0001213900-25-021165 | 10-K | XBRL Viewer

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Income Taxes - Schedule of Components of the Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Feb. 05, 2024
Deferred tax assets
Net operating loss carryforwards	$ 2,260
Research and development credits	3,080
Stock-based compensation	3,063
Accruals and other	424
Lease liability	203
Intangibles	1,477
Capitalized R&D expenses	10,994
Total deferred tax assets	21,501
Deferred tax liabilities
Right- of- use asset	(184)
Total deferred tax liabilities	(184)
Less valuation allowance	(21,317)
Deferred tax assets, net

Fair Value Measurements - Schedule of Fair Value Hierarchy for Financial Assets Measured (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Feb. 06, 2024
Cash equivalents
Cash equivalents	$ 52,175
Marketable securities, current
Marketable securities, current	314,073
Marketable securities, long-term
Marketable securities, long-term	18,069
Cash equivalents and marketable securities	384,317
Level 1 [Member]
Cash equivalents
Cash equivalents	6,350
Marketable securities, long-term
Cash equivalents and marketable securities	6,350
Level 2 [Member]
Cash equivalents
Cash equivalents	45,825
Marketable securities, current
Marketable securities, current	314,073
Marketable securities, long-term
Marketable securities, long-term	18,069
Cash equivalents and marketable securities	377,967
Level 3 [Member]
Cash equivalents
Cash equivalents
Marketable securities, current
Marketable securities, current
Marketable securities, long-term
Marketable securities, long-term
Cash equivalents and marketable securities
Money market funds [Member]
Cash equivalents
Cash equivalents	6,350
Money market funds [Member] \| Level 1 [Member]
Cash equivalents
Cash equivalents	6,350
Money market funds [Member] \| Level 2 [Member]
Cash equivalents
Cash equivalents
Money market funds [Member] \| Level 3 [Member]
Cash equivalents
Cash equivalents
US Treasury Securities [Member]
Cash equivalents
Cash equivalents	19,660
Marketable securities, current
Marketable securities, current	190,792
Marketable securities, long-term
Marketable securities, long-term	13,607
US Treasury Securities [Member] \| Level 2 [Member]
Cash equivalents
Cash equivalents	19,660
Marketable securities, current
Marketable securities, current	190,792
Marketable securities, long-term
Marketable securities, long-term	13,607
US Treasury Securities [Member] \| Level 3 [Member]
Cash equivalents
Cash equivalents
Marketable securities, current
Marketable securities, current
Marketable securities, long-term
Marketable securities, long-term
US Government Agency Securities [Member]
Cash equivalents
Cash equivalents	3,988
Marketable securities, current
Marketable securities, current	12,966
Marketable securities, long-term
Marketable securities, long-term	4,462
US Government Agency Securities [Member] \| Level 1 [Member]
Cash equivalents
Cash equivalents
Marketable securities, current
Marketable securities, current
Marketable securities, long-term
Marketable securities, long-term
US Government Agency Securities [Member] \| Level 2 [Member]
Cash equivalents
Cash equivalents	3,988
Marketable securities, current
Marketable securities, current	12,966
Marketable securities, long-term
Marketable securities, long-term	4,462
US Government Agency Securities [Member] \| Level 3 [Member]
Cash equivalents
Cash equivalents
Marketable securities, current
Marketable securities, current
Marketable securities, long-term
Marketable securities, long-term
Commercial Papers [Member]
Cash equivalents
Cash equivalents	22,177
Marketable securities, current
Marketable securities, current	34,811
Commercial Papers [Member] \| Level 1 [Member]
Cash equivalents
Cash equivalents
Marketable securities, current
Marketable securities, current
Commercial Papers [Member] \| Level 2 [Member]
Cash equivalents
Cash equivalents	22,177
Marketable securities, current
Marketable securities, current	34,811
Commercial Papers [Member] \| Level 3 [Member]
Cash equivalents
Cash equivalents
Marketable securities, current
Marketable securities, current
Corporate Debt Securities [Member]
Marketable securities, current
Marketable securities, current	75,504
Corporate Debt Securities [Member] \| Level 1 [Member]
Marketable securities, current
Marketable securities, current
Corporate Debt Securities [Member] \| Level 2 [Member]
Marketable securities, current
Marketable securities, current	75,504
Corporate Debt Securities [Member] \| Level 3 [Member]
Marketable securities, current
Marketable securities, current

Reverse Recapitalization and Pre-Closing Financing - Schedule of the Assets and Liabilities (Details) $ in Thousands	Aug. 29, 2024 USD ($)
Schedule of the Assets and Liabilities [Abstract]
Cash and cash equivalents	$ 4,940
Other current assets	114
Accrued liabilities	(54)
Net assets acquired	$ 5,000

Reverse Recapitalization and Pre-Closing Financing

11 Months Ended

Dec. 31, 2024

Reverse Recapitalization and Pre-Closing Financing [Abstract]

Reverse Recapitalization and Pre-Closing Financing

3. Reverse Recapitalization and Pre-Closing Financing

As described within the Reverse Recapitalization and Pre-Closing Financing section in Note 1, on August 29, 2024, the reverse recapitalization between Pre-Merger Oruka and ARCA was consummated. The Merger was accounted for as a reverse recapitalization in accordance with U.S. GAAP. At the effective time of the Merger, substantially all of the assets of ARCA consisted of cash and cash equivalents and other nominal non-operating assets and liabilities. No goodwill or intangible assets were recognized.

As part of the recapitalization, the Company acquired the assets and liabilities listed below (in thousands):

	August 29, 2024
Cash and cash equivalents	$	4,940
Other current assets		114
Accrued liabilities		(54	)
Net assets acquired	$	5,000

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2024	Feb. 06, 2024
Current assets:
Cash and cash equivalents	$ 61,575
Marketable securities, current	314,073
Subscription receivable		1
Prepaid expenses and other current assets	1,221
Total current assets	376,869	1
Marketable securities, long-term	18,069
Property and equipment, net	162
Operating lease right-of-use assets	876
Other non-current assets	43
Total assets	396,019	1
Current liabilities:
Accounts payable	3,462
Accrued expenses and other current liabilities	3,346
Operating lease liability, current	213
Total current liabilities	13,043
Operating lease liability, non-current	755
Total liabilities	13,798
Commitments and contingencies (Note 13)
Stockholders’ equity:
Common stock, $0.001 and $0.001 par value as of December 31, 2024 and February 6, 2024, respectively; 545,000,000 and 65,000,000 shares authorized, 37,440,510 and 3,197,975 shares issued and outstanding as of December 31, 2024 and February 6, 2024, respectively	37
Additional paid-in capital	463,018	1
Accumulated other comprehensive loss	(41)
Accumulated deficit	(83,724)
Total stockholders’ equity	382,221	1
Total liabilities, convertible preferred stock and stockholders’ equity	396,019	1
Related Party
Current liabilities:
Related party accounts payable and other current liabilities	6,022
Series A Convertible Preferred Stock
Current liabilities:
Convertible preferred stock, value
Series A Non-Voting Convertible Preferred Stock
Current liabilities:
Convertible preferred stock, value
Series B Non-Voting Convertible Preferred Stock
Stockholders’ equity:
Series B non-voting convertible preferred stock, $0.001 par value; 251,504 and no shares authorized as of December 31, 2024 and February 6, 2024, respectively; 137,138 and no shares issued and outstanding as of December 31, 2024 and February 6, 2024, respectively	$ 2,931

Consolidated Statement of Convertible Preferred Stock and Stockholders’ Equity - 11 months ended Dec. 31, 2024 - USD ($)
$ in Thousands

Convertible Preferred Stock

Series A

Convertible Preferred Stock

Series A Non-Voting

Convertible Preferred Stock

Series B Non-Voting

Common Stock

Additional Paid-in Capital

Accumulated Other Comprehensive Gain (Loss)

Accumulated Deficit

Series A

^[1]

Total

Balances at Feb. 05, 2024

$ 3

$ (2)

$ 1

Balances (in Shares) at Feb. 05, 2024

3,197,975

Issuance of common stock

$ 2

(2)

Issuance of common stock (in Shares)

2,207,553

Issuance of Series A convertible preferred stock, net of issuance costs of $69

$ 2,931

Issuance of Series A convertible preferred stock, net of issuance costs of $69 (in Shares)

20,000,000

Exchange of Series A convertible preferred stock for Series B non-voting convertible preferred stock upon the closing of the reverse capitalization

$ (2,931)

$ 2,931

2,931

Exchange of Series A convertible preferred stock for Series B non-voting convertible preferred stock upon the closing of the reverse capitalization (in Shares)

(20,000,000)

137,138

Conversion of convertible notes (including accrued interest) into common stock upon the closing of the reverse recapitalization

$ 3

26,445

26,448

Conversion of convertible notes (including accrued interest) into common stock upon the closing of the reverse recapitalization (in Shares)

2,722,207

Issuance of common stock and pre-funded warrants in the Pre-Closing Financing

$ 20

248,437

248,457

Issuance of common stock and pre-funded warrants in the Pre-Closing Financing (in Shares)

20,061,932

Issuance costs of Pre-Closing Financing and reverse recapitalization

(20,504)

Issuance of common stock to former stockholders of ARCA biopharma, Inc. in connection with the closing of reverse recapitalization

$ 1

4,999

5,000

Issuance of common stock to former stockholders of ARCA biopharma, Inc. in connection with the closing of reverse recapitalization (in Shares)

1,208,883

Issuance of common stock, Series A non-voting convertible preferred stock, and pre-funded warrants in connection with the PIPE Financing

$ 56,097

$ 6

144,433

144,439

Issuance of common stock, Series A non-voting convertible preferred stock, and pre-funded warrants in connection with the PIPE Financing (in Shares)

2,439

5,600,000

Issuance costs of PIPE Financing

$ (3,263)

(8,592)

Conversion of Series A non-voting convertible preferred stock to common stock

$ (52,834)

$ 2

52,832

52,834

Conversion of Series A non-voting convertible preferred stock to common stock (in Shares)

(2,439)

2,439,000

Issuance of common stock under employee stock purchase plan

Issuance of common stock under employee stock purchase plan (in Shares)

2,960

Reclassification of the Paruka warrant from liability to equity

10,357

Stock-based compensation expense

4,562

Unrealized loss on marketable securities

(41)

Net loss

(65,037)

(83,724)

$ (1,918)

(83,724)

Balances at Dec. 31, 2024

$ 2,931

$ 37

$ 463,018

$ (41)

$ (83,724)

$ 382,221

Balances (in Shares) at Dec. 31, 2024

137,138

37,440,510

[1]	The weighted-average number of shares of as-converted Company Series A Preferred Stock used in the loss allocation was 495,191 for the period from February 6, 2024 (inception) to December 31, 2024.

Reverse Recapitalization and Pre-Closing Financing (Tables)

11 Months Ended

Dec. 31, 2024

Reverse Recapitalization and Pre-Closing Financing [Abstract]

Schedule of the Assets and Liabilities

As part of the recapitalization, the Company acquired the assets and liabilities listed below (in thousands):

	August 29, 2024
Cash and cash equivalents	$	4,940
Other current assets		114
Accrued liabilities		(54	)
Net assets acquired	$	5,000

Commitment and Contingencies - Schedule of Company’s Operating Lease Liabilities Showing the Aggregate Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Feb. 06, 2024
Schedule of Company’s Operating Lease Liabilities Showing the Aggregate Lease Payments [Abstract]
2025	$ 369
2026	494
2027	380
Total undiscounted lease payments	1,243
Less: imputed interest	(275)
Total discounted lease payments	968
Less: current portion of lease liability	(213)
Non-current portion of lease liability	$ 755

Segment Disclosures

11 Months Ended

Dec. 31, 2024

Segment Disclosures [Abstract]

Segment Disclosures

10. Segment disclosures

The Company operates and manages its business activities on a consolidated basis and operates in one reportable segment.

The Company operates as a single reportable and operating segment. Its Chief Executive Officer, serving as the Chief Operating Decision Maker (“CODM”), oversees operations on an aggregated basis to allocate resources effectively. In assessing the Company’s financial performance, the CODM regularly reviews total operating expenses and consolidated net loss.

The measure of segment assets is reported on the balance sheet as total consolidated assets. The Company’s long-lived assets consist primarily of property and equipment, net. As of December 31, 2024 all of long-lived assets were in the U.S.

The table below is a summary of the segment loss from operations, including significant segment expenses (in thousands):

	Period from February 6, 2024 (Inception) to December 31, 2024
Research and development personnel-related (excluding stock-based compensation)	$	3,959
General and administrative personnel-related (excluding stock-based compensation)		5,054
Research and development stock-based compensation		11,992
General and administrative stock-based compensation		2,927
External research and development		57,680
Other research and development		1,429
General and administrative, excluding personnel-related and stock-based compensation		5,082
Total operating expenses		88,123
Loss from operations	$	(88,123	)

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

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+ Details

Stock-Based Compensation - Schedule of Weighted-Average Assumptions Used in Calculating the Fair Value of the Awards (Details)	11 Months Ended
	Dec. 31, 2024
Stock Option [Member]
Schedule of Weighted-Average Assumptions Used in Calculating the Fair Value of the Awards [Line Items]
Expected term (in years)	6 years 1 month 6 days
Expected volatility	100.21%
Risk-free interest rate	4.26%
Expected dividend yield
Employee Warrants [Member]
Schedule of Weighted-Average Assumptions Used in Calculating the Fair Value of the Awards [Line Items]
Expected term (in years)	6 years 1 month 6 days
Expected volatility	99.02%
Risk-free interest rate	4.15%
Expected dividend yield

Summary of Significant Accounting Policies (Tables)

11 Months Ended

Dec. 31, 2024

Summary of Significant Accounting Policies [Abstract]

Schedule of Property and Equipment

Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset as follows:

		Estimated Useful Life
Furniture and fixtures		3-5 years
Computer and office equipment		3-5 years

Subsequent Events (Details) - Subsequent Event [Member] $ in Millions	Feb. 28, 2025 USD ($)
Subsequent Events [Line Items]
Lease initial period	54 months
Future lease payment	$ 1.6

Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share Attributable to Stockholders (Details)
$ / shares in Units, $ in Thousands

11 Months Ended

Dec. 31, 2024

USD ($)

$ / shares

Schedule of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders [Line Items]

Net loss | $

$ (83,724)

Weighted average shares outstanding – Basic | shares

16,789,362

Weighted average shares outstanding – Diluted | shares

16,789,362

Loss per share – Basic | $ / shares

$ (3.87)

Loss per share – Diluted | $ / shares

$ (3.87)

Series A Preferred Stock [Member]

Schedule of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders [Line Items]

Net loss | $

$ (1,918)

^[1]

Weighted average shares outstanding – Basic | shares

495

^[1]

Weighted average shares outstanding – Diluted | shares

495

^[1]

Loss per share – Basic | $ / shares

$ (3,873.25)

Loss per share – Diluted | $ / shares

$ (3,873.25)

Series B Preferred Stock [Member]

Schedule of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders [Line Items]

Net loss | $

$ (16,769)

^[2]

Weighted average shares outstanding – Basic | shares

51,946

^[2]

Weighted average shares outstanding – Diluted | shares

51,946

^[2]

Loss per share – Basic | $ / shares

$ (322.81)

Loss per share – Diluted | $ / shares

$ (322.81)

Common Stock [Member]

Schedule of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders [Line Items]

Net loss | $

$ (65,037)

Weighted average shares outstanding – Basic | shares

16,789,362

Weighted average shares outstanding – Diluted | shares

16,789,362

Loss per share – Basic | $ / shares

$ (3.87)

Loss per share – Diluted | $ / shares

$ (3.87)

[1]	The weighted-average number of shares of as-converted Company Series A Preferred Stock used in the loss allocation was 495,191 for the period from February 6, 2024 (inception) to December 31, 2024.
[2]	The weighted-average number of shares of as-converted Company Series B Preferred Stock used in the loss allocation was 4,328,844 for the period from February 6, 2024 (inception) to December 31, 2024.

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

Cash equivalents and Marketable Securities - Schedule of Cash Equivalents and Marketable Securities (Details) $ in Thousands	Dec. 31, 2024 USD ($)
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	$ 384,358
Gross Unrealized Gains, Cash Equivalents and Marketable Securities	70
Gross Unrealized Losses, Cash Equivalents and Marketable Securities	(111)
Fair Value, Cash Equivalents and Marketable Securities	384,317
Cash Equivalents [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	52,174
Gross Unrealized Gains, Cash Equivalents and Marketable Securities	4
Gross Unrealized Losses, Cash Equivalents and Marketable Securities	(3)
Fair Value, Cash Equivalents and Marketable Securities	52,175
Cash Equivalents [Member] \| Money market funds [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	6,350
Gross Unrealized Gains, Cash Equivalents and Marketable Securities
Gross Unrealized Losses, Cash Equivalents and Marketable Securities
Fair Value, Cash Equivalents and Marketable Securities	6,350
Cash Equivalents [Member] \| U.S. treasury securities [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	19,656
Gross Unrealized Gains, Cash Equivalents and Marketable Securities	4
Gross Unrealized Losses, Cash Equivalents and Marketable Securities
Fair Value, Cash Equivalents and Marketable Securities	19,660
Cash Equivalents [Member] \| U.S. government agency securities [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	3,988
Gross Unrealized Gains, Cash Equivalents and Marketable Securities
Gross Unrealized Losses, Cash Equivalents and Marketable Securities
Fair Value, Cash Equivalents and Marketable Securities	3,988
Cash Equivalents [Member] \| Commercial papers [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	22,180
Gross Unrealized Gains, Cash Equivalents and Marketable Securities
Gross Unrealized Losses, Cash Equivalents and Marketable Securities	(3)
Fair Value, Cash Equivalents and Marketable Securities	22,177
Marketable Securities [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	314,060
Gross Unrealized Gains, Cash Equivalents and Marketable Securities	66
Gross Unrealized Losses, Cash Equivalents and Marketable Securities	(53)
Fair Value, Cash Equivalents and Marketable Securities	314,073
Marketable Securities [Member] \| U.S. treasury securities [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	190,748
Gross Unrealized Gains, Cash Equivalents and Marketable Securities	55
Gross Unrealized Losses, Cash Equivalents and Marketable Securities	(11)
Fair Value, Cash Equivalents and Marketable Securities	190,792
Marketable Securities [Member] \| U.S. government agency securities [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	12,967
Gross Unrealized Gains, Cash Equivalents and Marketable Securities	1
Gross Unrealized Losses, Cash Equivalents and Marketable Securities	(2)
Fair Value, Cash Equivalents and Marketable Securities	12,966
Marketable Securities [Member] \| Commercial papers [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	34,808
Gross Unrealized Gains, Cash Equivalents and Marketable Securities	3
Gross Unrealized Losses, Cash Equivalents and Marketable Securities
Fair Value, Cash Equivalents and Marketable Securities	34,811
Marketable Securities [Member] \| Corporate debt securities [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	75,537
Gross Unrealized Gains, Cash Equivalents and Marketable Securities	7
Gross Unrealized Losses, Cash Equivalents and Marketable Securities	(40)
Fair Value, Cash Equivalents and Marketable Securities	75,504
Marketable Securities,Long-Term [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	18,124
Gross Unrealized Gains, Cash Equivalents and Marketable Securities
Gross Unrealized Losses, Cash Equivalents and Marketable Securities	(55)
Fair Value, Cash Equivalents and Marketable Securities	18,069
Marketable Securities,Long-Term [Member] \| U.S. treasury securities [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	13,639
Gross Unrealized Gains, Cash Equivalents and Marketable Securities
Gross Unrealized Losses, Cash Equivalents and Marketable Securities	(32)
Fair Value, Cash Equivalents and Marketable Securities	13,607
Marketable Securities,Long-Term [Member] \| U.S. government agency securities [Member]
Cash equivalents
Amortized Cost, Cash Equivalents and Marketable Securities	4,485
Gross Unrealized Gains, Cash Equivalents and Marketable Securities
Gross Unrealized Losses, Cash Equivalents and Marketable Securities	(23)
Fair Value, Cash Equivalents and Marketable Securities	$ 4,462

Income Taxes - Schedule of Unrecognized Tax Benefits (Details) $ in Thousands	11 Months Ended
	Dec. 31, 2024 USD ($)
Schedule of Unrecognized Tax Benefits [Abstract]
Beginning balance
Changes related to tax positions taken in the current year	1,047
Ending balance	$ 1,047

Stock-Based Compensation - Schedule of Award Types of Company’s Stock-Based Compensation Expense (Details) $ in Thousands	11 Months Ended
	Dec. 31, 2024 USD ($)
Schedule of Award Types of Company’s Stock-Based Compensation Expense [Line Items]
Total stock-based compensation expense	$ 14,919
Paruka warrant obligation [Member]
Schedule of Award Types of Company’s Stock-Based Compensation Expense [Line Items]
Total stock-based compensation expense	10,357
Employee warrants [Member]
Schedule of Award Types of Company’s Stock-Based Compensation Expense [Line Items]
Total stock-based compensation expense	2,899
Stock options [Member]
Schedule of Award Types of Company’s Stock-Based Compensation Expense [Line Items]
Total stock-based compensation expense	1,626
Employee stock purchase plan [Member]
Schedule of Award Types of Company’s Stock-Based Compensation Expense [Line Items]
Total stock-based compensation expense	$ 37

Convertible Preferred Stock and Stockholders’ Equity - Schedule of Common Stock Reserved for Future Issuance (Details) - shares	Dec. 31, 2024	Aug. 29, 2024
Schedule of Common Stock Reserved for Future Issuance [Line Items]
Total shares of common stock reserved	27,556,257
Outstanding and Issued Stock Options [Member]
Schedule of Common Stock Reserved for Future Issuance [Line Items]
Total shares of common stock reserved	1,567,760
Pre-funded Warrants [Member]
Schedule of Common Stock Reserved for Future Issuance [Line Items]
Total shares of common stock reserved	6,202,207
Paruka Warrant Obligation [Member]
Schedule of Common Stock Reserved for Future Issuance [Line Items]
Total shares of common stock reserved	596,930
Employee Warrants [Member]
Schedule of Common Stock Reserved for Future Issuance [Line Items]
Total shares of common stock reserved	3,054,358
Shares issuable on conversion of Company Series B Preferred Stock [Member]
Schedule of Common Stock Reserved for Future Issuance [Line Items]
Total shares of common stock reserved	11,428,149
2024 Stock Incentive Plan [Member]
Schedule of Common Stock Reserved for Future Issuance [Line Items]
Total shares of common stock reserved	4,246,324
2024 Stock Incentive Plan [Member] \| Outstanding and Issued Stock Options [Member]
Schedule of Common Stock Reserved for Future Issuance [Line Items]
Total shares of common stock reserved	388,567
2024 Employee Stock Purchase Plan [Member]
Schedule of Common Stock Reserved for Future Issuance [Line Items]
Total shares of common stock reserved	460,529	463,489

Stock-Based Compensation - Schedule of Employee Warrant Activity (Details) - Employee Warrants [Member] - USD ($) $ / shares in Units, $ in Thousands	11 Months Ended
	Dec. 31, 2024
Schedule of Employee Warrant Activity [Line Items]
Beginning Balance (in Shares)
Beginning Balance (in Shares)
Aggregate Intrinsic Value, Beginning Balance
Ending Balance (in Shares)	3,054,358
Ending Balance (in Shares)	$ 7.8
Ending Balance (in Shares)	9 years 6 months
Aggregate Intrinsic Value, Ending Balance	$ 35,400
Number of Employee Warrants Outstanding, Vested and expected to vest	3,054,358
Weighted Average Exercise Price Per Share, Vested and expected to vest	$ 7.8
Weighted Average Remaining Contractual Term, Vested and expected to vest	9 years 6 months
Aggregate Intrinsic Value, Vested and expected to vest	$ 35,400
Number of Employee Warrants Outstanding, Vested and exercisable
Weighted Average Exercise Price Per Share, Vested and exercisable
Aggregate Intrinsic Value, Vested and exercisable
Number of Granted	3,054,358
Weighted Average,Granted	$ 7.8
Number of Employee Warrants Outstanding, Exercised
Weighted Average Exercise Price Per Share, Exercised
Number of Employee Warrants Outstanding, Forfeited
Weighted Average Exercise Price Per Share, Forfeited

Nature of the Business and Basis of Presentation

11 Months Ended

Dec. 31, 2024

Nature of the Business and Basis of Presentation [Abstract]

Nature of the Business and Basis of Presentation

1. Nature of the Business and Basis of Presentation

Background and Basis of Presentation

Oruka Therapeutics, Inc., together with its subsidiaries (collectively, the “Company”), formerly known as ARCA biopharma, Inc. (“ARCA”), is a clinical-stage biotechnology company that is the result of the reverse recapitalization discussed below. Prior to the reverse recapitalization, the private company Oruka Therapeutics, Inc. (“Pre-Merger Oruka”) was established and incorporated under the laws of the state of Delaware on February 6, 2024 (referred to in the Notes as the inception of the Company). The Company is headquartered in Menlo Park, California. The Company is focused on developing novel monoclonal antibody therapeutics for psoriasis (“PsO”) and other inflammatory and immunology (“I&I”) indications.

The accompanying consolidated financial statements reflect the operations of the Company and its wholly-owned subsidiaries. Intercompany balances and transactions have been eliminated in consolidation. The accompanying consolidated financial statements have been prepared in conformity with United States (“U.S.”) generally accepted accounting principles (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”).

Reverse Recapitalization and Pre-Closing Financing

On August 29, 2024 (the “Merger Closing”), the Company completed the acquisition (the “Merger”) of Pre-Merger Oruka pursuant to an Agreement and Plan of Merger and Reorganization, dated as of April 3, 2024 (the “Merger Agreement”). Following the transactions contemplated by the Merger Agreement, Pre-Merger Oruka merged with and into Atlas Merger Sub Corp., a wholly owned subsidiary of ARCA and following that, Pre-Merger Oruka then merged with and into Atlas Merger Sub II, LLC (“Second Merger Sub”), with Second Merger Sub being the surviving entity. Second Merger Sub changed its corporate name to “Oruka Therapeutics Operating Company, LLC.” On August 29, 2024, the Company changed its name from “ARCA biopharma, Inc.” to “Oruka Therapeutics, Inc.” and its Nasdaq ticker symbol from “ABIO” to “ORKA”.

Following consummation of the Merger, the Company effected a 1-for-12 reverse stock split (the “Reverse Stock Split”) of the common stock, par value $0.001 per share, of the Company (“Company Common Stock”), which became effective on September 3, 2024. The Company Common Stock commenced trading on a post-Reverse Stock Split, post-Merger basis at the opening of trading on September 3, 2024. The Company is led by the Pre-Merger Oruka management team and remains focused on developing biologics to optimize the treatment of inflammatory skin diseases.

Immediately prior to the execution and delivery of the Merger Agreement on April 3, 2024, certain new and existing investors of Pre-Merger Oruka entered into a subscription agreement with Pre-Merger Oruka (the “Subscription Agreement”), pursuant to which, and on the terms and subject to the conditions of which, immediately prior to the Closing, those investors purchased shares of common stock of Pre-Merger Oruka (“Pre-Merger Oruka Common Stock”) and Pre-Merger Oruka pre-funded warrants for gross proceeds of approximately $275.0 million (which includes $25.0 million of proceeds previously received from the issuance of the Convertible Note (as defined in Note 7) and accrued interest on such note which converted to shares of Pre-Merger Oruka Common Stock) (the “Pre-Closing Financing”). The Company incurred transaction costs of $20.5 million which was recorded as a reduction to additional paid-in capital in the consolidated financial statements. At the Merger Closing, the shares of Pre-Merger Oruka Common Stock and Pre-Merger Oruka pre-funded warrants issued pursuant to the Subscription Agreement were converted into shares of Company Common Stock and pre-funded warrants of Company Common Stock in accordance with the Exchange Ratio (defined below).

In accordance with an Exchange Ratio determined by terms of the Merger Agreement and upon the effective time of the First Merger (the “First Effective Time”), (i) each then-issued and outstanding share of Pre-Merger Oruka Common Stock including outstanding and unvested Pre-Merger Oruka restricted stock and shares of Pre-Merger Oruka Common Stock issued in connection with the Subscription Agreement, were converted into the right to receive a number of shares of Company Common Stock, equal to the Exchange Ratio of 6.8569 shares of Company Common Stock, which were subject to the same vesting provisions as those immediately prior to the Merger, (ii) each share of Pre-Merger Oruka Series A convertible preferred stock, par value $0.0001 (“Pre-Merger Oruka Series A Preferred Stock”), outstanding immediately prior to the First Effective Time was converted into the right to receive a number of shares of ARCA Series B non-voting convertible preferred stock, par value $0.001 per share (“Company Series B Preferred Stock”), which are convertible into shares of Company Common Stock, at a conversion ratio of approximately 83:3332:1 (iii) each outstanding option to purchase Pre-Merger Oruka Common Stock was converted into an option to purchase shares of Company Common Stock, (iv) each outstanding warrant to purchase shares of Pre-Merger Oruka Common Stock was converted into a warrant to purchase shares of Company Common Stock, and (v) each share of Company Common Stock issued and outstanding at the First Effective Time remain issued and outstanding in accordance with its terms and such shares. Subsequent to the close of the merger, the common stock shares were then subject to the reverse stock split of 1-for-12 effected on September 3, 2024.

As part of the Pre-Closing Financing and the Merger Closing, investors in the Pre-Closing Financing received 22,784,139 shares of Company Common Stock in exchange for 39,873,706 shares of Pre-Merger Oruka Common Stock (which includes the issuance of 2,722,207 shares of Company Common Stock in exchange for 4,764,032 shares of Pre-Merger Oruka Common Stock on the conversion of Convertible Note along with the accrued interest through the conversion date) and 5,522,207 Company pre-funded warrants in exchange for 9,664,208 Pre-Merger pre-funded warrants.

The Merger was accounted for as a reverse recapitalization in accordance with U.S. GAAP. Under this method of accounting, Pre-Merger Oruka was deemed to be the accounting acquirer for financial reporting purposes. This determination was primarily based on the fact that, immediately following the Merger: (i) Pre-Merger Oruka stockholders own a substantial majority of the voting rights in the combined company; (ii) Pre-Merger Oruka’s largest stockholders retain the largest interest in the combined company; (iii) Pre-Merger Oruka designated a majority of the initial members of the board of directors of the combined company; and (iv) Pre-Merger Oruka’s executive management team became the management team of the combined company. Accordingly, for accounting purposes: (i) the Merger was treated as the equivalent of Pre-Merger Oruka issuing stock to acquire the net assets of ARCA, and (ii) the reported historical operating results of the combined company prior to the Merger are those of Pre-Merger Oruka. Additional information regarding the Merger is included in Note 3.

Reverse Stock Split

On September 3, 2024, the Company effected the Reverse Stock Split, a 1-for-12 reverse stock split of Company Common Stock. The par value per share and the number of authorized shares were not adjusted as a result of the Reverse Stock Split. The shares of Company Common Stock underlying outstanding stock options, common stock warrants and other equity instruments were proportionately reduced and the respective exercise prices, if applicable, were proportionately increased in accordance with the terms of the agreements governing such securities. All references to common stock, options to purchase common stock, outstanding common stock warrants, common stock share data, per share data, and related information contained in the consolidated financial statements have been retrospectively adjusted to reflect the effect of the Reverse Stock Split for all periods presented, unless otherwise specifically indicated or the context otherwise requires.

PIPE Financing

On September 11, 2024, the Company entered into a Securities Purchase Agreement for a private placement (the “PIPE Financing”) with certain institutional and accredited investors. The closing of the PIPE Financing occurred on September 13, 2024.

Pursuant to the Securities Purchase Agreement, the investors purchased an aggregate of 5,600,000 shares of Company Common Stock at a purchase price of $23.00 per share, an aggregate of 2,439 shares of the Company’s Series A non-voting convertible preferred stock, par value $0.001 per share (“Company Series A Preferred Stock”), at a purchase price of $23,000.00 per share (each Company Series A Preferred Stock is convertible into 1,000 shares of Company Common Stock), and pre-funded warrants to purchase an aggregate of 680,000 shares of Company Common Stock at a purchase price of $22.999 per pre-funded warrant, for aggregate net proceeds of approximately $188.7 million (net of issuance costs of $11.9 million).

Liquidity and Going Concern

Since its inception, the Company has devoted substantially all of its resources to advancing the development of its portfolio of programs, organizing and staffing the Company, business planning, raising capital, and providing general and administrative support for these operations. Current and future programs will require significant research and development efforts, including preclinical and clinical trials, and regulatory approvals to commercialization. Until such time as the Company can generate significant revenue from product sales, if ever, the Company expects to finance its operating activities through a combination of equity offerings and debt financings.

The Company has not generated any revenue from product sales or other sources and has incurred significant operating losses and negative cash flows from operations since inception. For the period from February 6, 2024 (inception) to December 31, 2024, the Company has incurred a net loss of $83.7 million and used net cash of $57.8 million for its operating activities.

As of December 31, 2024, the Company had cash, cash equivalents, and marketable securities of $393.7 million. The Company’s management expects that the existing cash, cash equivalents, and marketable securities will be sufficient to fund the Company’s operating plans for at least twelve months from the date these consolidated financial statements were issued. The Company expects that its research and development and general and administrative costs will continue to increase significantly, including in connection with conducting future pre-clinical activities and clinical trials and manufacturing for its existing product candidates and any future product candidates to support commercialization and providing general and administrative support for its operations, including the costs associated with operating as a public company. The Company’s ability to access capital when needed is not assured and, if capital is not available to the Company when, and in the amounts needed, the Company may be required to significantly curtail, delay, or discontinue one or more of its research or development programs or the commercialization of any product candidate, or be unable to expand its operations or otherwise capitalize on the Company’s business opportunities, as desired, which could materially harm the Company’s business, financial condition and results of operations.

Segment Disclosures (Details)	11 Months Ended
Segment Disclosures (Details)	Dec. 31, 2024
Segment Disclosures [Abstract]
Operating segment	1
Reporting segment	1

Income Taxes

11 Months Ended

Dec. 31, 2024

Income Taxes [Abstract]

Income Taxes

11. Income Taxes

No provision for income taxes was recorded for the period from February 6, 2024 (inception) to December 31, 2024.

The following table summarizes the loss before income tax expense by jurisdiction for the periods indicated:

	Period from February 6, 2024 (Inception) to December 31, 2024
Domestic	$	(83,724	)
Foreign		—
Loss before income tax expense	$	(83,724	)

For the period from February 6, 2024 (inception) to December 31, 2024, the Company recognized no provision or benefit from income taxes. The difference between the Company’s provision for income taxes and the amounts computed by applying the statutory federal income tax rate to income before income taxes is as follows:

	Period from February 6, 2024 (Inception) to December 31, 2024
Tax benefit derived by applying the federal statutory rate to income before income taxes		(21.00	)%
Permanent differences		(0.18	)
Research and development credits		(3.41	)
Other		(0.87	)
Change in the valuation allowance		25.46
Income tax (benefit) expense		0.00	%

The components of the deferred tax assets and liabilities consist of the following (in thousands):

	December 31, 2024
Deferred tax assets
Net operating loss carryforwards	$	2,260
Research and development credits		3,080
Stock-based compensation		3,063
Accruals and other		424
Lease liability		203
Intangibles		1,477
Capitalized R&D expenses		10,994
Total deferred tax assets		21,501
Deferred tax liabilities
Right- of- use asset		(184	)
Total deferred tax liabilities		(184	)
Less valuation allowance		(21,317	)
Deferred tax assets, net	$	—

The Company has established a full federal and state valuation allowance equal to the net deferred tax assets due to uncertainties regarding the realization of the deferred tax asset based on the Company’s lack of earnings history. The valuation allowance increased by $21.3 million primarily due to continuing loss from operations.

	December 31, 2024
Beginning balance as of February 6, 2024	$	—
Change in valuation allowance		21,317
Ending balance as of December 31, 2024	$	21,317

As of December 31, 2024, the Company had U.S. net operating loss carryforwards (“NOL”) of $10.8 million. The federal NOL carryforwards do not expire and can be utilized to offset up to 80% of the taxable income in any tax year. For the period from February 6, 2024 (inception) to December 31, 2024 the Company had federal tax credit carryforwards and state tax credit carryforwards of $3.8 million and $0.4 million, respectively. The federal credits will expire starting in 2044 if not utilized, and the state research credit can be carried forward indefinitely.

The Tax Reform Act of 1986 limits the use of net operating loss carryforwards in certain situations where changes occur in the stock ownership of a company. The annual limitation may result in the expiration of net operating losses and credits before utilization. The Company has not performed a Section 382 analysis through December 31, 2024. To the extent that an assessment is completed in the future, the Company’s ability to utilize tax attributes could be restricted on a year-by-year basis and certain attributes could expire before they are utilized. The Company will examine the impact of any potential ownership changes in the future.

A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands):

	Period from February 6, 2024 (Inception) to December 31, 2024
Beginning balance as of February 6, 2024	$	—
Changes related to tax positions taken in the current year		1,047
Ending balance as of December 31, 2024	$	1,047

The Company includes penalties and interest expense related to income taxes as a component of income tax expense, as necessary. As of December 31, 2024, the Company had no accrued interest or penalties related to uncertain tax positions.

The Company will be filing initial year income tax returns in the United States federal jurisdiction and state jurisdictions. Due to net operating loss carryforwards, the statute of limitations will remain open for income tax examination.

- Definition

The entire disclosure for income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 2: http://www.xbrl.org/2003/role/exampleRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477891/740-270-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 2
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482603/740-30-50-2

+ Details

Consolidated Statement of Operations and Comprehensive Loss (Parentheticals) $ in Thousands	11 Months Ended
	Dec. 31, 2024 USD ($)
Research and development
Related party amount	$ 42,640
General and administrative
Related party amount	1,364
Interest Expense
Related party amount	$ 1,468

Related Party Transactions

11 Months Ended

Dec. 31, 2024

Related Party Transactions

15. Related Party Transactions

Paragon and Paruka each beneficially own less than 5% of the Company’s capital stock through their respective holdings of Company Common Stock.

Fairmount beneficially owns more than 5% of the Company’s capital, currently has one representative appointed to the Board, and beneficially owns more than 5% of Paragon. Fairmount appointed Paragon’s board of directors and has the contractual right to approve the appointment of any executive officers of Paragon.

The following is a summary of related party accounts payable and other current liabilities (in thousands):

	December 31, 2024
Paragon reimbursable Option Agreements’ fees	$	1,482
Paragon milestone payments for Option Agreement		4,000
Paragon reimbursable other research expenses		515
Paragon reimbursable patent expenses		25
Total	$	6,022

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-Section 50
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-Section 50
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-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
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-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

+ Details

Consolidated Statement of Operations and Comprehensive Loss
$ in Thousands

11 Months Ended

Dec. 31, 2024

USD ($)

$ / shares

Operating expenses

Research and development

$ 75,060

^[1]

General and administrative

13,063

^[2]

Total operating expenses

88,123

Loss from operations

(88,123)

Other income (expense)

Interest income

5,863

Interest expense

(1,468)

^[3]

Other income, net

Total other income, net

4,399

Net loss

(83,724)

Unrealized loss on marketable securities

(41)

Comprehensive loss

$ (83,765)

Net loss per share attributable to stockholders, basic (in Dollars per share) | $ / shares

$ (3.87)

Net loss per share attributable to stockholders, diluted (in Dollars per share) | $ / shares

$ (3.87)

Weighted-average shares used in computing net loss per share attributable to stockholders, basic (in Shares) | shares

16,789,362

Weighted-average shares used in computing net loss per share attributable to stockholders, diluted (in Shares) | shares

16,789,362

Series A Non-Voting Convertible Preferred Stockholders

Other income (expense)

Net loss per share attributable to stockholders, basic (in Dollars per share) | $ / shares

$ (3,873.25)

Net loss per share attributable to stockholders, diluted (in Dollars per share) | $ / shares

$ (3,873.25)

Weighted-average shares used in computing net loss per share attributable to stockholders, basic (in Shares) | shares

495

Weighted-average shares used in computing net loss per share attributable to stockholders, diluted (in Shares) | shares

495

Series B Non-Voting Convertible Preferred Stockholders

Other income (expense)

Net loss per share attributable to stockholders, basic (in Dollars per share) | $ / shares

$ (322.81)

Net loss per share attributable to stockholders, diluted (in Dollars per share) | $ / shares

$ (322.81)

Weighted-average shares used in computing net loss per share attributable to stockholders, basic (in Shares) | shares

51,946

Weighted-average shares used in computing net loss per share attributable to stockholders, diluted (in Shares) | shares

51,946

[1]	Includes related party amount of $42,640 for the period from February 6, 2024 (inception) to December 31, 2024
[2]	Includes related party amount of $1,364 for the period from February 6, 2024 (inception) to December 31, 2024
[3]	Includes related party amount of $1,468 for the period from February 6, 2024 (inception) to December 31, 2024

Note Payable with Related Party

11 Months Ended

Dec. 31, 2024

Note Payable with Related Party [Abstract]

Note Payable with Related Party

7. Note Payable with Related Party

In March 2024, Pre-Merger Oruka entered into a Series A Preferred Stock and Convertible Note Purchase Agreement (the “Purchase Agreement”) with Fairmount Healthcare Fund II, L.P. (“Fairmount”), whereby Pre-Merger Oruka issued a convertible note (the “Convertible Note”), with an initial principal amount of $25.0 million that, at the time of issuance, could be converted into Pre-Merger Oruka Series A Preferred Stock (or a series of preferred shares that is identical in respect to the shares of preferred shares issued in its next equity financing) or shares of Pre-Merger Oruka Common Stock in exchange for aggregate proceeds of $25.0 million. The Convertible Note accrued interest at a rate of 12.0% per annum. At issuance, the Convertible Note required all unpaid interest and principal to mature on December 31, 2025 (the “Maturity Date”) and prepayment was not permitted without prior written consent of Fairmount.

The Company assessed all terms and features of the Convertible Note in order to identify any potential embedded features that would require bifurcation. As part of this analysis, the Company assessed the economic characteristics and risks of the embedded features. The Company determined that the share settled redemption feature was clearly and closely related to the debt host and did not require separate accounting. The Company determined that the conversion options of the Convertible Note were not clearly and closely associated with a debt host. However, these features did not meet the definition of a derivative under ASC 815, Derivatives and Hedging, and as a result, did not require separate accounting as a derivative liability.

The Company paid debt issuance costs of less than $0.1 million in relation to the Convertible Note. The debt issuance costs were reflected as a reduction of the carrying value of Convertible Note on the consolidated balance sheet and were being amortized as interest expense over the term of the Convertible Note using the effective interest method. For the period from February 6, 2024 (inception) to December 31, 2024, the Company recognized interest expenses related to the Convertible Note of $1.5 million, which includes non-cash interest expense related to the amortization of debt issuance.

Immediately prior to the completion of the Merger (see Note 1), the Convertible Note was converted into shares of Pre-Merger Oruka Common Stock based on the aggregate principal amount of $25.0 million, plus unpaid accrued interest of $1.5 million divided by the conversion price which was determined based upon the Company’s fully-diluted capitalization immediately prior to the Merger. At the effective time of the Merger, the Pre-Merger Oruka Common Stock issued upon the conversion of the Convertible Note (including accrued interest) automatically converted into 2,722,207 shares of Company Common Stock. As of December 31, 2024, the Convertible Note is not outstanding.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Stock-Based Compensation - Schedule of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands		11 Months Ended
	Feb. 06, 2024	Dec. 31, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of Stock Options Outstanding, Ending Balance		1,567,760
Weighted Average Exercise Price Per Share, Ending Balance		$ 11.39
Weighted Average Remaining Contractual Term (in Years), Ending Balance		9 years 4 months 24 days
Aggregate Intrinsic Value, Ending Balance		$ 15,470
Number of Stock Options Outstanding, Vested and expected to vest		1,567,760
Weighted Average Exercise Price Per Share, Vested and expected to vest, September 30, 2024		$ 11.39
Weighted Average Remaining Contractual Term (in Years), Vested and expected to vest, September 30, 2024		9 years 4 months 24 days
Aggregate Intrinsic Value, Vested and expected to vest		$ 15,470
Number of Stock Options Outstanding, Exercisable
Weighted Average Exercise Price Per Share, Exercisable,
Weighted Average Remaining Contractual Term (in Years), Exercisable
Aggregate Intrinsic Value, Exercisable
Stock Options, Granted		1,567,760
Weighted Average Exercise Price Per Share, Granted		$ 11.39
Stock Options, Exercised
Weighted Average Exercise Price Per Share, Exercised
Stock Options, Forfeited
Weighted Average Exercise Price Per Share, Forfeited

Segment Disclosures - Schedule of Segment Loss from Operations (Details)
$ in Thousands

11 Months Ended

Dec. 31, 2024

USD ($)

Schedule of Segment Loss from Operations [Line Items]

Research and development personnel-related expense (excluding stock-based compensation)

$ 75,060

^[1]

General and administrative personnel-related expense (excluding stock-based compensation)

13,063

^[2]

Total operating expenses

88,123

Loss from operations

(88,123)

Operating Expense Excluding Personnel Related And Stock Based Compensation [Member]

Schedule of Segment Loss from Operations [Line Items]

Research and development personnel-related expense (excluding stock-based compensation)

3,959

General and administrative personnel-related expense (excluding stock-based compensation)

5,054

Research and development stock-based compensation [Member]

Schedule of Segment Loss from Operations [Line Items]

Research and development personnel-related expense (excluding stock-based compensation)

11,992

General and administrative stock-based compensation [Member]

Schedule of Segment Loss from Operations [Line Items]

Research and development personnel-related expense (excluding stock-based compensation)

2,927

External [Member]

Schedule of Segment Loss from Operations [Line Items]

Research and development personnel-related expense (excluding stock-based compensation)

57,680

Other [Member]

Schedule of Segment Loss from Operations [Line Items]

Research and development personnel-related expense (excluding stock-based compensation)

1,429

Operating Expense Excluding Personnel Related And Stock Based Compensation [Member]

Schedule of Segment Loss from Operations [Line Items]

General and administrative personnel-related expense (excluding stock-based compensation)

$ 5,082

[1]	Includes related party amount of $42,640 for the period from February 6, 2024 (inception) to December 31, 2024
[2]	Includes related party amount of $1,364 for the period from February 6, 2024 (inception) to December 31, 2024

Summary of Significant Accounting Policies (Details)	11 Months Ended
Summary of Significant Accounting Policies (Details)	Dec. 31, 2024 USD ($)
Summary of Significant Accounting Policies [Line Items]
Federal Deposit Insurance Corporation	$ 250,000

Income Taxes - Schedule of Loss Before Income Tax Expense (Details) $ in Thousands	11 Months Ended
	Dec. 31, 2024 USD ($)
Schedule of Loss Before Income Tax Expense [Abstract]
Domestic	$ (83,724)
Foreign
Loss before income tax expense	$ (83,724)

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

Summary of Significant Accounting Policies - Schedule of Property and Equipment (Details)	Dec. 31, 2024
Minimum [Member] \| Furniture and fixtures [Member]
Schedule of Property and Equipment [Line Items]
Estimated useful life	3 years
Minimum [Member] \| Computer and office equipment [Member]
Schedule of Property and Equipment [Line Items]
Estimated useful life	3 years
Maximum [Member] \| Furniture and fixtures [Member]
Schedule of Property and Equipment [Line Items]
Estimated useful life	5 years
Maximum [Member] \| Computer and office equipment [Member]
Schedule of Property and Equipment [Line Items]
Estimated useful life	5 years

Cover - USD ($) $ in Millions	11 Months Ended
Cover - USD ($) $ in Millions	Dec. 31, 2024	Feb. 28, 2025	Jun. 30, 2024
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Financial Statement Error Correction [Flag]	false
Entity Interactive Data Current	Yes
ICFR Auditor Attestation Flag	false
Amendment Flag	false
Document Period End Date	Dec. 31, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Entity Information [Line Items]
Entity Registrant Name	Oruka Therapeutics, Inc.
Entity Central Index Key	0000907654
Entity File Number	000-22873
Entity Tax Identification Number	36-3855489
Entity Incorporation, State or Country Code	DE
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Public Float			$ 39.7
Entity Contact Personnel [Line Items]
Entity Address, Address Line One	855 Oak Grove Avenue
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Menlo Park
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94025
Entity Phone Fax Numbers [Line Items]
City Area Code	(650)
Local Phone Number	606-7910
Entity Listings [Line Items]
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	ORKA
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		37,440,510

Net Loss Per Share

11 Months Ended

Dec. 31, 2024

Net Loss per Share [Abstract]

Net Loss Per Share

14. Net Loss per Share

Basic and diluted net loss per share attributable to stockholders were calculated as follows (in thousands, except share and per share data):

	Period from February 6, 2024 (Inception) to December 31, 2024
	Loss Allocation			Weighted Average Shares Outstanding		Loss Per Share, Basic and Diluted
Common Stock	$	(65,037	)		16,789,362	$	(3.87	)
Company Series A Preferred Stock ⁽¹⁾		(1,918	)		495	$	(3,873.25	)
Company Series B Preferred Stock ⁽²⁾		(16,769	)		51,946	$	(322.81	)
Net loss	$	(83,724	)

(1)	The weighted-average number of shares of as-converted Company Series A Preferred Stock used in the loss allocation was 495,191 for the period from February 6, 2024 (inception) to December 31, 2024.

(2)	The weighted-average number of shares of as-converted Company Series B Preferred Stock used in the loss allocation was 4,328,844 for the period from February 6, 2024 (inception) to December 31, 2024.

For the computation of basic net loss per share attributable to stockholders, the amount of weighted-average shares outstanding excludes all shares of unvested restricted common stock as such shares are not considered outstanding for accounting purposes until vested. The amount of weighted-average shares outstanding includes the pre-funded warrants as the exercise price is negligible and these warrants are fully vested and exercisable.

The potential shares of common stock that were excluded from the computation of diluted net loss per share attributable to stockholders for the periods presented because including them would have had an anti-dilutive effect were as follows:

	December 31, 2024
Outstanding employee warrants to purchase common stock		3,054,358
Outstanding unvested restricted stock awards		2,207,553
Outstanding and issued common stock options		1,567,760
Outstanding and issued warrant to Paruka		596,930
Total		7,426,601

Commitment and Contingencies (Tables)

11 Months Ended

Dec. 31, 2024

Commitment and Contingencies [Abstract]

Schedule of Company’s Supplemental Cash Flow Information Related to Leases

The following table presents the Company’s supplemental cash flow information related to leases (in thousands):

		Period from February 6, 2024 (Inception) to December 31, 2024
Cash paid for amounts included in the measurement of lease liabilities		$	116

Schedule of Company’s Operating Lease Liabilities Showing the Aggregate Lease Payments

The following table summarizes a maturity analysis of the Company’s operating lease liabilities showing the aggregate lease payments as of December 31, 2024 (in thousands):

Year ending December 31,	Amount
2025	$	369
2026		494
2027		380
Total undiscounted lease payments		1,243
Less: imputed interest		(275	)
Total discounted lease payments		968
Less: current portion of lease liability		(213	)
Non-current portion of lease liability	$	755

Stock-Based Compensation - Schedule of RSA Activity (Details) - Restricted Stock Award [Member] - $ / shares	11 Months Ended
	Dec. 31, 2024
Schedule of RSA Activity [Line Items]
Beginning Balance (in Shares)
Weighted Average Grant Date Fair Value, Unvested balance, Beginning
Unvested balance, Number of Granted	2,207,553
Weighted Average Grant Date Fair Value, Granted
Ending Balance (in Shares)	2,207,553
Weighted Average Grant Date Fair Value, Unvested balance, Ending

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

Cash equivalents and Marketable Securities - Schedule of Marketable Securities at Estimated Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Feb. 06, 2024
Schedule of Marketable Securities at Estimated Fair Value [Abstract]
Due in one year or less	$ 314,073
Due in 1-2 years	18,069
Total	$ 332,142

Accounting Policies, by Policy (Policies)

11 Months Ended

Dec. 31, 2024

Summary of Significant Accounting Policies [Abstract]

Use of Estimates

Use of Estimates

The preparation of the Company’s consolidated financial statements in conformity with U.S. GAAP requires management to make estimates, assumptions, and judgments that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the date of the consolidated financial statements and the reported amounts of income and expenses during the reporting periods. Significant estimates and assumptions reflected within these consolidated financial statements include but are not limited to research and development expenses and related prepaid or accrued costs and the valuation of stock-based compensation awards and related expenses. The Company bases its estimates on known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates, as there are changes in circumstances, facts, and experience. Actual results could differ materially from those estimates or assumptions.

Concentrations of Credit Risk and Other Risks and Uncertainties

Concentrations of Credit Risk and Other Risks and Uncertainties

Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents and marketable securities. The Company’s investment policy limits investments to high credit quality securities issued by the U.S. government, U.S. government-sponsored agencies, highly rated banks, and corporate issuers, subject to certain concentration limits and restrictions on maturities. The Company’s cash, cash equivalents and marketable securities are held by financial institutions that management believes are of high credit quality. The financial instruments that potentially subject the Company to a concentration of credit risk consist principally of cash deposits. Accounts at the Company’s U.S. banking institution are insured by the Federal Deposit Insurance Corporation (“FDIC”) up to $250,000 per depositor. As of December 31, 2024, the balance at the Company’s U.S. banking institution exceeded the FDIC limits. The Company has not experienced any losses on its deposits of cash and cash equivalents and its accounts are monitored by management to mitigate risk. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents, and bond issuers.

The Company is dependent on third-party organizations to research, develop, manufacture, and process its product candidates for its development programs, including its two most advanced programs, ORKA-001 and ORKA-002. The Company expects to continue to be dependent on a small number of manufacturers to supply it with its requirements for all products. The Company’s research and development programs could be adversely affected by a significant interruption in the supply of the necessary materials. A significant amount of the Company’s research and development activities are performed under its agreements with Paragon Therapeutics, Inc. (“Paragon”) (see Note 12).

Cash and Cash Equivalents

Cash and Cash Equivalents

The Company considers all highly liquid investments with an original maturity of three months or less at the time of initial purchase to be cash equivalents. The cash equivalents were comprised of investments in money market funds, U. S. treasury securities, U.S. government agency securities, and debt securities and are stated at fair value.

Marketable Securities

Marketable Securities

The Company invests in marketable securities, primarily securities issued by the U.S. government and its agencies, commercial paper and corporate debt securities. The Company’s marketable securities are classified as available-for-sale and reported at fair value, with unrealized gains and losses included as a component of accumulated other comprehensive loss.

For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in other income (expense) in the results of operations. For available-for-sale debt securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, an allowance is recorded for the difference between the present value of cash flows expected to be collected and the amortized cost basis of the security. Impairment losses attributable to credit loss factors are charged against the allowance when management believes an available-for-sale security is uncollectible or when either of the criteria regarding intent or requirement to sell is met.

Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit loss factors are recognized as a component of accumulated other comprehensive loss, net of unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in other income, net, in the results of operations.

Marketable securities with stated maturities of greater than three months from the date of purchase but less than one year from the consolidated balance sheet date are classified as current, while marketable securities with maturities in one year or beyond one year from the consolidated balance sheet date are classified as long-term. The cost of securities sold is determined using the specific-identification method. Interest earned and adjustments for the amortization of premiums and discounts on investments are included in interest income on the consolidated statements of operations and comprehensive loss.

Debt Issuance Costs

Debt Issuance Costs

Debt issuance costs incurred in connection with the Convertible Note (see Note 7) are recorded as a reduction of the carrying value of the notes payable liability on the Company’s balance sheet and are amortized to interest expense over the term of the loan using the effective interest method. At the effective time of the Merger the Converted Note was converted to common stock and is no longer on the balance sheet as of December 31, 2024.

Subscription Receivable

Subscription Receivable

The Company accounts for any notes received in exchange for common stock as a subscription receivable, provided the note underlying the receivable is paid prior to the date the financial statement is available to be issued.

Fair Value Measurements

Fair Value Measurements

Certain assets and liabilities are carried at fair value under U.S. GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:

●

Level 1 — Quoted prices in active markets that are identical assets or liabilities.

●

Level 2 — Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.

●

Level 3 — Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies, and similar techniques.

The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy described above (see Note 4). The carrying values of the Company’s prepaid expenses and other current assets, accounts payable and accrued expenses and other current liabilities approximate their fair values due to their relatively short maturity period.

Property and Equipment

Property and Equipment

Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset as follows:

		Estimated Useful Life
Furniture and fixtures		3-5 years
Computer and office equipment		3-5 years

Classification of Convertible Preferred Stock

Classification of Convertible Preferred Stock

Prior to the reverse recapitalization, the Company had classified its Pre-Merger Oruka Series A Preferred Stock outside of stockholders’ equity on the Company’s consolidated balance sheet because the holders of such stock have certain liquidation rights in the event of a deemed liquidation event that, in certain situations, is not solely within the control of the Company and would require the redemption of the then-outstanding convertible preferred stock.

Upon the closing of the Merger, the Company converted its Pre-Merger Oruka Series A Preferred Stock to Company Series B Preferred Stock and has classified the Company Series B Preferred Stock within stockholders’ equity on its consolidated balance sheet because the Company Series B Preferred Stock is not redeemable or puttable to the Company by the holder under any circumstances.

In connection with the PIPE Financing (see Note 1) the Company issued Company Series A Preferred Stock, and has classified the Company Series A Preferred Stock outside of stockholders’ equity on the Company’s consolidated balance sheet because the holders of such stock have certain rights (see Note 8) that, in certain situations, is not solely within the control of the Company and would require the redemption of the then-outstanding convertible preferred stock. In November 2024, the Company Series A Preferred Stock shares were converted to common stock, and as of December 31, 2024, there were no shares of Company Series A Preferred Stock outstanding.

Note Payable to Related Party

Note Payable to Related Party

The Company accounted for the Convertible Note (as defined in Note 7) at amortized cost. The Company considered if optional conversion features are required to be bifurcated and separately accounted for as a derivative. Costs related to the issuance of the Convertible Note were recorded as a debt discount, amortized over the term of the Convertible Note (see Note 7) and were accounted for as interest expense in other income (expenses) within the consolidated statement of operations and comprehensive loss using the effective interest method. At the effective time of the Merger, shares of Pre-Merger Oruka Common Stock issued pursuant to the conversion of the Convertible Note (including accrued interest) automatically converted into shares of Company Common Stock (see Note 1).

Research and Development Contract Costs Accruals

Research and Development Contract Costs Accruals

The Company records the costs associated with research studies and manufacturing development as incurred. These costs are a significant component of the Company’s research and development expenses, with a substantial portion of the Company’s ongoing research and development activities conducted by third-party service providers, including contract research organizations (“CROs”) and contract manufacturing organizations (“CMOs”), and the Company’s related-party Paragon (see Note 12).

The Company accrues for expenses resulting from obligations under its two antibody discovery and option agreements (the “Option Agreements”) (see Note 12), by and among Paragon, Paruka Holding LLC (“Paruka”), an entity formed by Paragon as a vehicle to hold equity in the Company, and the Company as well as agreements with CROs, CMOs, and other outside service providers for which payment flows do not match the periods over which materials or services are provided to the Company. Accruals are recorded based on estimates of services received and efforts expended pursuant to agreements established with Paragon, CROs, CMOs, and other outside service providers. These estimates are typically based on contracted amounts applied to the proportion of work performed and determined through analysis with internal personnel and external service providers as to the progress or stage of completion of the services. The Company makes significant judgments and estimates in determining the accrual balance in each reporting period. If advance payments are made to Paragon, a CRO, CMO, or outside service provider, the payments will be recorded as a prepaid asset which will be expensed as the contracted services are performed. Changes in these estimates that result in material changes to the Company’s accruals could materially affect the Company’s results of operations. As of December 31, 2024, the Company has not experienced any material deviations between accrued and actual research and development expenses.

Leases

Leases

At the lease commencement date, when control of the underlying asset is transferred from the lessor to the Company, the Company classifies a lease as either an operating or finance lease and recognizes a right-of-use (“ROU”) asset and a current and non-current lease liability, as applicable, in the balance sheet if the lease has a term greater than one year. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise its option.

At the lease commencement date, operating lease liabilities and their corresponding ROU assets are recorded at the present value of future minimum lease payments over the expected remaining lease term. The Company determines the present value of lease payments using the implicit rate, if it is readily determinable, or the risk-free discount rate for a period comparable with that of the lease term. For operating leases, lease expense for lease payments is recognized on a straight-line basis over the lease term. For finance leases, lease expense includes amortization expense of the ROU asset recognized on a straight-line basis over the lease term and interest expense recognized on the finance lease liability. In addition, certain adjustments to the ROU asset may be required for items such as lease prepayments, incentives received or initial direct costs. As of December 31, 2024, the Company has one operating lease and no finance leases.

The Company accounts for lease and non-lease components related to operating leases as a single lease component. The Company has elected that costs associated with leases having an initial term of 12 months or less are recognized in the consolidated statement of operations and comprehensive loss on a straight-line basis over the lease term and are not recorded on its consolidated balance sheets. Variable lease expense is recognized as incurred and consists primarily of real estate taxes, utilities, and other office space related expenses.

Segment Reporting

Segment Reporting

Research and Development Costs

Research and Development Costs

Research and development costs are expensed as incurred. Research and development costs include salaries and bonuses, stock-based compensation, employee benefits, and external costs of vendors and consultants engaged to conduct research and development activities, as well as allocated human resource costs, information technology costs, and facility-related costs, including rent, maintenance, utilities, and depreciation.

Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses on the accompanying consolidated balance sheet. The prepaid amounts are expensed as the related goods are delivered or the services are performed, or when it is no longer expected that the goods will be delivered, or the services rendered. If nonrefundable advance payments represent a one-time cost for obtaining goods or services, with anticipated benefits to be utilized within a year of period end, the payment is expensed immediately.

General and Administrative Expenses

General and Administrative Expenses

General and administrative expenses consist primarily of salaries and bonuses, stock-based compensation, employee benefits, finance and administration costs, patent and intellectual property costs, professional fees, as well as allocated human resource costs, information technology costs, and facility-related costs, including rent, maintenance, utilities and depreciation.

Commitments and Contingencies

Commitments and Contingencies

The Company is subject to contingent liabilities, such as legal proceedings and claims, that arise in the ordinary course of business activities. The Company accrues for loss contingencies when losses become probable and are reasonably estimable. If the reasonable estimate of the loss is a range and no amount within the range is a better estimate, the minimum amount of the range is recorded as a liability on the balance sheet. The Company does not accrue for contingent losses that, in its judgment, are considered to be reasonably possible, but not probable; however, it discloses the range of reasonably possible losses. As of December 31, 2024, no liabilities were recorded for loss contingencies (see Note 13).

Stock-Based Compensation

Stock-Based Compensation

The Company estimates the fair value of its stock awards using the Black-Scholes option pricing model, which uses as inputs the fair value of the Company’s common stock, and certain management estimates, including the expected stock price volatility, the expected term of the award, the risk-free interest rate, and expected dividends. Expected volatility is calculated based on reported volatility data for a representative group of publicly traded companies for which historical information is available. The Company selects companies with comparable characteristics with historical share price information that approximates the expected term of the equity-based awards. The Company computes the historical volatility data using the daily closing prices for the selected companies’ shares during the equivalent period that approximates the calculated expected term of the stock options. The Company will continue to apply this method until a sufficient amount of historical information regarding the volatility of its stock price becomes available. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant commensurate with the expected term assumption. For employee and non-employee awards (except the Paruka warrant) the Company uses the simplified method, under which the expected term is presumed to be the midpoint between the vesting date and the end of the contractual term. The Company utilizes this method due to lack of historical exercise data. For the Paruka warrant, the contractual term is used for the expected term. The expected dividend yield is assumed to be zero as the Company has no current plans to pay any dividends on common stock.

The Company measures restricted common stock awards (“RSAs”) using the difference, if any, between the purchase price per share of the award and the fair value of the Company’s common stock at the date of grant.

The Company grants stock options, restricted stock awards, and warrants that are subject to service or performance-based vesting conditions. Compensation expense for awards to employees and directors with service-based vesting conditions is recognized using the straight-line method over the requisite service period, which is generally the vesting period of the respective award. Compensation expense for awards to non-employees with service-based vesting conditions is recognized in the same manner as if the Company had paid cash in exchange for the goods or services, which is generally over the vesting period of the award. Forfeitures are accounted for as they occur. As of each reporting date, the Company estimates the probability that specified performance criteria will be met and does not recognize compensation expense until it is probable that the performance-based vesting condition will be achieved.

The Company has issued stock options, warrants, and RSAs with service-based and performance-based vesting conditions.

The Company recognizes the compensation expense for the option to purchase common stock under the Employee Stock Purchase Plan (“ESPP”), based on the fair value of the common stock estimated using the closing price of the Company’s common stock as reported on the date of offering, less the purchase discount percentage provided for in the plan.

The Company classifies stock-based compensation expense in its consolidated statement of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified or in which the award recipient’s service payments are classified, as applicable.

Comprehensive Loss

Comprehensive Loss

Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and events other than those with stockholders. The Company’s unrealized gains and losses on marketable securities represent the only component of other comprehensive loss that are excluded from the reported net loss and that are presented in the consolidated statement of comprehensive loss.

Net Loss per Share Attributable to Stockholders

Net Loss per Share Attributable to Stockholders

Basic and diluted net loss attributable to stockholders per share is presented in conformity with the two-class method required for participating securities (Pre-Merger Oruka Series A Preferred Stock). Basic earnings per share is computed by dividing net income available to each class of shares by the weighted-average number of shares of common stock and participating securities outstanding during the period. Pre-funded warrants were included as the exercise price is negligible and these warrants are fully vested and exercisable. Company Series A Preferred Stock and Company Series B Preferred Stock share the same characteristics as Common Stock and have no substantive preference attributed to them and, accordingly, have been considered as classes of Common Stock in the computation of net loss per share regardless of their legal form.

Net loss is allocated to common stock based on its proportional ownership on an as-converted basis. Net loss is not allocated to participating securities as they do not have an obligation to fund losses. The weighted-average number of shares outstanding of common stock reflects changes in ownership over the periods presented. See Note 8 — Convertible Preferred Stock and Stockholders’ Equity.

Diluted net loss per share is computed by dividing the net loss attributable to stockholders adjusted for income (expenses), net of tax, related to any diluted securities, by the weighted-average number of shares of common stock and potentially dilutive securities outstanding for the period. For purposes of this calculation, stock options to purchase common stock, employee warrants to purchase common stock, and unvested RSAs are considered potential dilutive common shares.

The Company generated a net loss for the periods presented. Accordingly, basic and diluted net loss per share is the same because the inclusion of the potentially dilutive securities would be anti-dilutive.

Other income, net

Other income, net

Other income, net, consists of interest earned on the Company’s cash, cash equivalents, and marketable securities; interest expense on the convertible note from a related party and foreign currency transactions gains and losses.

Income Taxes

Income Taxes

The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the financial statements or in the Company’s tax returns. Deferred tax assets and liabilities are determined based on the differences between the financial statement basis and tax basis of assets and liabilities using enacted tax rates in effect for the years in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. The potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies.

The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more likely than not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the consolidated financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties. The Company had accrued no amounts for interest or penalties related to uncertain tax positions as of December 31, 2024.

Recently Adopted Accounting Pronouncements

Recently Adopted Accounting Pronouncements

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which enhances the segment disclosure requirements for public entities on an annual and interim basis. Under this standard, public entities will be required to disclose significant segment expenses that are regularly provided to the CODM and included within each reported measure of segment profit or loss. Additionally, current annual disclosures about a reportable segment’s profit or loss and assets will be required on an interim basis. Entities will also be required to disclose information about the CODM’s title and position at the Company along with an explanation of how the CODM uses the reported measures of segment profit or loss in their assessment of segment performance and deciding how to allocate resources. Finally, ASU 2023-07 requires all segment disclosures for public entities that have only a single reportable segment. The amendments in ASU 2023-07 are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. The Company adopted ASU 2023-07 in 2024 and additional required disclosures have been included in Note 10.

Recently Issued Accounting Pronouncements

Recently Issued Accounting Pronouncements

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This ASU expands disclosures in an entity’s income tax rate reconciliation table and disclosures regarding taxes paid both in the U.S. and foreign jurisdictions. This update is effective beginning with the Company’s 2025 fiscal year annual reporting period. The Company is currently evaluating the impact of the adoption of this ASU on its consolidated financial statements.

In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. This ASU requires more detailed disclosures, on an annual and interim basis, about specified categories of expenses (including employee compensation, depreciation, and amortization) included in certain expense captions presented on the face of the income statement. This ASU is effective for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. This ASU may be applied either prospectively or retrospectively. The Company is currently evaluating the impact of the adoption of this ASU on its consolidated financial statements.

Convertible Preferred Stock and Stockholders’ Equity (Tables)

11 Months Ended

Dec. 31, 2024

Convertible Preferred Stock and Stockholders’ Equity [Abstract]

Schedule of Convertible Preferred Stock

As of December 31, 2024, convertible preferred stock consisted of the following (in thousands, except share data):

	December 31, 2024
	Preferred Stock Authorized		Preferred Stock Issued and Outstanding		Carrying Value		Common Stock Issuable Upon Conversion
Series B convertible preferred stock		251,504		137,138		2,931		11,428,149

Schedule of Common Stock Reserved for Future Issuance

As of December 31, 2024, the Company had common stock reserved for future issuance as follows:

	December 31, 2024
Shares issuable on conversion of Company Series B Preferred Stock		11,428,149
Shares issuable upon exercise of pre-funded warrants		6,202,207
Shares issuable upon exercise of warrant under the Paruka Warrant Obligation		596,930
Outstanding and issued stock options		1,567,760
Outstanding and issued employee warrants		3,054,358
Shares available for grant under 2024 Stock Incentive Plan		4,246,324
Shares available for grant under 2024 Employee Stock Purchase Plan		460,529
Total shares of common stock reserved		27,556,257

Consolidated Statement of Convertible Preferred Stock and Stockholders’ Equity (Parentheticals) $ in Thousands	11 Months Ended
	Dec. 31, 2024 USD ($)
Statement of Stockholders' Equity [Abstract]
Issuance of Series A Convertible Preferred Stock, Net of Issuance Costs	$ 69

Cash equivalents and Marketable Securities (Tables)

11 Months Ended

Dec. 31, 2024

Cash equivalents and Marketable Securities [Abstract]

Schedule of Cash Equivalents and Marketable Securities

Cash equivalents and marketable securities, which are classified as available-for-sale, consisted of the following as of December 31, 2024 (in thousands):

	December 31, 2024
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash equivalents
Money market funds	$	6,350	$	—	$	—		$	6,350
U.S. treasury securities		19,656		4		—			19,660
U.S. government agency securities		3,988		—		—			3,988
Commercial papers		22,180		—		(3	)		22,177
Total cash equivalents		52,174		4		(3	)		52,175
Marketable securities
Marketable securities, current
U.S. treasury securities		190,748		55		(11	)		190,792
U.S. government agency securities		12,967		1		(2	)		12,966
Commercial papers		34,808		3		—			34,811
Corporate debt securities		75,537		7		(40	)		75,504
Total marketable securities, current		314,060		66		(53	)		314,073
Marketable securities, long-term
U.S. treasury securities		13,639		—		(32	)		13,607
U.S. government agency securities		4,485		—		(23	)		4,462
Total marketable securities, long-term		18,124		—		(55	)		18,069
Total cash equivalents and marketable securities	$	384,358	$	70	$	(111	)	$	384,317

Schedule of Available-for-Sale Securities in an Unrealized Loss Position

The following table summarizes the available-for-sale securities in an unrealized loss position, aggregated by major security type and length of time in a continuous unrealized loss position, for which an allowance for credit losses was not recorded as of December 31, 2024, (in thousands):

	December 31, 2024
	Less than 12 months					12 months or longer				Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Cash equivalents
Commercial papers	$	18,199	$	(3	)	$	—	$	—	$	18,199	$	(3	)
Marketable securities
Marketable securities, current
U.S. treasury securities		49,904		(11	)		—		—		49,904		(11	)
U.S. government agency securities		4,713		(2	)		—		—		4,713		(2	)
Corporate debt securities		39,468		(40	)		—		—		39,468		(40	)
Marketable securities, long-term											—		—
U.S. treasury securities		13,607		(32	)		—		—		13,607		(32	)
U.S. government agency securities		4,462		(23	)		—		—		4,462		(23	)
Total	$	130,353	$	(111	)	$	—	$	—	$	130,353	$	(111	)

Schedule of Marketable Securities at Estimated Fair Value

The following table summarizes the contractual maturities of the Company’s marketable securities at estimated fair value (in thousands):

	December 31, 2024
Due in one year or less	$	314,073
Due in 1-2 years		18,069
Total	$	332,142

Convertible Preferred Stock and Stockholders’ Equity

11 Months Ended

Dec. 31, 2024

Convertible Preferred Stock and Stockholders’ Equity [Abstract]

Convertible Preferred Stock and Stockholders’ Equity

8. Convertible Preferred Stock and Stockholders’ Equity

Pre-Funded Warrants

In August 2024, pursuant to the Subscription Agreement and immediately prior to the Closing, certain new and current investors purchased pre-funded warrants, which, at the effective time of the Merger, were exercisable for 5,522,207 shares of Company Common Stock at a purchase price of approximately $9.70 per warrant. After the Merger, there are 5,522,207 pre-funded warrants outstanding and are exercisable for 5,522,207 shares of the Company Common Stock at an exercise price of $0.01 per share.

In September 2024, in connection with the PIPE Financing, the Company issued and sold 680,000 pre-funded warrants, at a purchase price of $22.999 per warrant, exercisable for 680,000 shares of Company Common Stock at an exercise price of $0.001 per share.

The pre-funded warrants were recorded as a component of stockholders’ equity within additional paid-in-capital and have no expiration date. As of December 31, 2024, none of the pre-funded warrants have been exercised and 6,202,207 pre-funded warrants remain outstanding.

Employee Warrants

In July 2024, Pre-Merger Oruka entered into a Subscription Agreement that provided for, among other things, the issuance of warrants to certain of Pre-Merger Oruka’s employees and directors immediately prior to the closing of the Merger. During the period from February 6, 2024 (inception) to December 31, 2024, 3,054,358 employee warrants were issued at an exercise price of $7.80 per warrant. These warrants vest over a period of four years. Per the terms of the Employee Warrant Agreement, the holders of the Company’s warrants shall not have any of the rights or privileges of a stockholder of the Company in respect of any shares purchasable upon the exercise of the warrant or any portion thereof unless and until a certificate or certificates representing such shares have been issued or a book entry representing such shares has been made and such shares have been deposited with the appropriate registered book-entry custodian. The Company recognizes compensation cost related to warrants on a straight-line basis over the requisite service period, which is the period in which the related services are received. As of December 31, 2024, none of the warrants have been exercised and 3,054,358 warrants remain outstanding.

Convertible Preferred Stock

In March 2024, Pre-Merger Oruka issued and sold an aggregate of 20,000,000 shares of Pre-Merger Oruka Series A Preferred Stock to Fairmount (see Note 15), at a purchase price of approximately $0.15 per share, for aggregate gross proceeds of $3.0 million. Pre-Merger Oruka incurred less than $0.1 million of issuance costs in connection with this transaction. Upon the issuance of the Pre-Merger Oruka Series A Preferred Stock, the Company assessed the embedded conversion and liquidation features of the securities as described below and determined that such features did not require the Company to separately account for these features.

In August 2024, upon the closing of the Merger, the Company converted the Pre-Merger Oruka Series A Preferred Stock to 137,138 shares of Company Series B Preferred Stock.

In September 2024, in connection with the PIPE Financing, the Company issued and sold an aggregate of 2,439 shares of the Company Series A Preferred Stock at a purchase price of $23,000.00 per share. In November 2024, the 2,439 shares of the Company Series A Preferred Stock were converted to 2,439,000 shares of Company Common Stock. As of December 31, 2024, there are no outstanding shares of Company Series A Preferred Stock.

As of December 31, 2024, convertible preferred stock consisted of the following (in thousands, except share data):

	December 31, 2024
	Preferred Stock Authorized		Preferred Stock Issued and Outstanding		Carrying Value		Common Stock Issuable Upon Conversion
Series B convertible preferred stock		251,504		137,138		2,931		11,428,149

Pursuant to the Certificate of Designation of Preferences, Rights and Limitations of the Series A Non-Voting Convertible Preferred Stock (the “Series A Certificate of Designation”) filed in connection with the PIPE Financing, holders of Company Series A Preferred Stock were entitled to receive dividends on shares of Company Series A Preferred Stock equal to, on an as-if-converted-to-Company Common Stock basis, and in the same form as, dividends actually paid on shares of Company Common Stock. Except as provided in the Series A Certificate of Designation or as otherwise required by law, the Company Series A Preferred Stock did not have voting rights. The Company Series A Preferred Stock shall rank on parity with the Company Common Stock and Company Series B Preferred Stock upon any liquidation, dissolution or winding-up of the Company. Subject to the terms and limitations contained in the Series A Certificate of Designation, the Company Series A Preferred Stock issued in the PIPE Financing will not become convertible until the Company’s stockholders approve the conversion of the Company Series A Preferred Stock into shares of Company Common Stock in accordance with the listing rules of the Nasdaq Stock Market (the “Stockholder Approval”), which, on issuance, resulted in the Company Series A Preferred Stock being classified outside of stockholders’ equity on the Company’s consolidated balance sheet. Following the Stockholder Approval in November 2024, each share of Company Series A Preferred Stock was automatically converted into 1,000 shares of Company Common Stock.

Pursuant to the Certificate of Designation of Preferences, Rights and Limitations of the Series B Non-Voting Convertible Preferred Stock (the “Series B Certificate of Designation”) filed in connection with the Merger, holders of Company Series B Preferred Stock are entitled to receive dividends on shares of Company Series B Preferred Stock equal to, on an as-if-converted-to-Company Common Stock basis, and in the same form as, dividends actually paid on shares of Company Common Stock. Except as provided in the Series B Certificate of Designation or as otherwise required by law, the Company Series B Preferred Stock does not have voting rights. The Company Series B Preferred Stock shall rank on parity with the Company Common Stock as to the distribution of assets upon any liquidation, dissolution, or winding-up of the Company. Each share of Company Series B Preferred Stock is convertible at the option of the holder, at any time, and without the payment of additional consideration by the holder. As of December 31, 2024, each outstanding share of Company Series B Preferred Stock was convertible into common stock at a ratio of approximately 83.3332:1.

Paruka Warrant

On December 31, 2024, the Company settled its 2024 obligations under the Paruka Warrant Obligation (defined below) by issuing Paruka a warrant to purchase 596,930 shares of Company Common Stock at an exercise price of $19.39 per share. The warrant has a term of 10 years, is fully vested, and is exercisable in part or full at any time during the term of the warrant. As of December 31, 2024, the warrant issued under the Paruka Warrant Obligation is outstanding and unexercised. See Note 9 for additional information on the Paruka Warrant Obligation.

Common Stock

As of December 31, 2024, the Certificate of Incorporation provides for 545,000,000 authorized shares of Company Common Stock. As of December 31, 2024, 37,440,510 shares of Company Common Stock were issued and outstanding, including 2,207,553 shares of RSAs issued and outstanding.

As of December 31, 2024, the Company had common stock reserved for future issuance as follows:

	December 31, 2024
Shares issuable on conversion of Company Series B Preferred Stock		11,428,149
Shares issuable upon exercise of pre-funded warrants		6,202,207
Shares issuable upon exercise of warrant under the Paruka Warrant Obligation		596,930
Outstanding and issued stock options		1,567,760
Outstanding and issued employee warrants		3,054,358
Shares available for grant under 2024 Stock Incentive Plan		4,246,324
Shares available for grant under 2024 Employee Stock Purchase Plan		460,529
Total shares of common stock reserved		27,556,257

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
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+ Details

Stock-Based Compensation

11 Months Ended

Dec. 31, 2024

Stock-Based Compensation [Abstract]

Stock-Based Compensation

9. Stock-Based Compensation

2024 Equity Incentive Plan

The 2024 Equity Incentive Plan (“2024 Plan”) was adopted by the board of directors of Pre-Merger Oruka on February 6, 2024. The 2024 Plan provided for Pre-Merger Oruka to grant stock options, restricted stock awards, restricted stock units, and other stock-based awards to employees, officers, directors, consultants, and advisors. Equity Incentive Stock options granted under the 2024 Plan generally vest over four years, subject to the participant’s continued service, and expire after ten years, although two non-employee stock options were granted with vesting terms less than four years. As of December 31, 2024, there are no shares of common stock available for issuance.

2024 Stock Incentive Plan

On August 22, 2024, the 2024 Stock Incentive Plan (“2024 Stock Plan”) was approved by the Company’s stockholders and on August 29, 2024, the board of directors of the Company (the “Board”) ratified the 2024 Stock Plan. The 2024 Stock Plan allows for the grant of stock options, stock appreciation rights, restricted stock awards, restricted stock units, other stockholder-based awards and incentive bonuses. The 2024 Stock Plan is administered by the Compensation Committee of the Board (the “Compensation Committee”) or another committee designated by the Board to administer the Plan. The initial share pool under the 2024 Stock Plan is 4,634,891 shares of Company Common Stock. During the period from February 6, 2024 (inception) to December 31, 2024, 388,567 shares were subject to outstanding stock options, and as of December 31, 2024, there were 4,246,324 shares available in the pool. The shares that may be issued under the 2024 Stock Plan will be automatically increased on January 1 of each year beginning in 2025 and ending with a final increase on January 1, 2034 in an amount equal to 5% of the diluted stock (including Company Common Stock, preferred stock and unexercised pre-funded warrants) on the preceding December 31, unless a lower, or no, increase is determined by the Compensation Committee. Current or prospective employees, officers, non-employee directors, and other independent service providers of the Company and its subsidiaries are eligible to participate in the 2024 Stock Plan.

2024 Employee Stock Purchase Plan

The 2024 Employee Stock Purchase Plan (the “ESPP”) became effective on August 29, 2024, at which time 463,489 shares of Company Common Stock were reserved for issuance. Eligible employees may purchase shares of Company Common Stock under the ESPP at 85% of the lower of the fair market value of the Company Common Stock as of the first or the last day of each offering period. Employees are limited to contributing 15% of the employee’s eligible compensation and may not purchase more than $25,000 of stock during any calendar year. The ESPP will terminate ten years from the first purchase date under the plan, unless terminated earlier by the board of directors.

The shares that may be issued under the ESPP will be automatically increased on January 1 of each year beginning in 2025 and ending with a final increase on January 1, 2034 in an amount equal to 1% of the diluted stock (including Company Common Stock, preferred stock and unexercised pre-funded warrants) on the preceding December 31, unless a lower, or no increase is determined by the Compensation Committee. During the period from February 6, 2024 (inception) to December 31, 2024, 2,960 shares of Company Common Stock were issued out of the ESPP and as of December 31, 2024, there were 460,529 shares of Company Common Stock available in the pool.

For the period February 6, 2024 (inception) to December 31, 2024, stock-based compensation expense related to the ESPP was less than $0.1 million.

Stock Option Valuation

The following table summarizes the weighted-average assumptions used in calculating the fair value of the awards for the period from February 6, 2024 (inception) to December 31, 2024:

	Period from February 6, 2024 (Inception) to December 31, 2024
Expected term (in years)		6.1
Expected volatility		100.21	%
Risk-free interest rate		4.26	%
Expected dividend yield		—

Stock Options

The following table summarizes the stock option activities under the 2024 Plan and 2024 Stock Plan for the period of February 6, 2024 (inception) through December 31, 2024:

	Number of Stock Options Outstanding		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value (in Thousands)
Balance as of February 6, 2024 (inception)		—	$	—		—	$	—
Granted		1,567,760	$	11.39
Exercised		—	$	—
Forfeited		—	$	—
Balance as of December 31, 2024		1,567,760	$	11.39		9.4	$	15,470
Vested and expected to vest, December 31, 2024		1,567,760	$	11.39		9.4	$	15,470
Exercisable, December 31, 2024		—	$	—		—	$	—

The weighted average grant-date fair value per share of stock options granted during the period from February 6, 2024 (inception) to December 31, 2024 was $9.12 per share. Aggregate intrinsic value represents the difference between the estimated fair value of the underlying Company Common Stock and the exercise price of outstanding, in-the-money employee stock options.

Restricted Stock Awards

In February 2024 and March 2024, the Company issued 2,207,553 shares of RSAs to certain employees, directors, and consultants at a price of $0.0001 per share, the then par value of Pre-Merger Oruka Common Stock. Such RSAs have service-based vesting conditions only and vest over a four-year period, during which time all unvested shares are subject to forfeiture in the event the holder’s service with the Company voluntarily or involuntarily terminates. As of December 31, 2024, none of the RSAs had vested. For the period February 6, 2024 (inception) to December 31, 2024, stock-based compensation expense related to RSAs was less than $0.1 million.

The following table summarizes the RSA activity for the period from February 6, 2024 (inception) through December 31, 2024:

	Number of RSAs		Weighted Average Grant Date Fair Value
Unvested balance as of February 6, 2024 (inception)		—	$	—
Granted		2,207,553	$	—
Unvested balance as of December 31, 2024		2,207,553	$	—

Option Agreements and the Paruka Warrant Obligation

As part of the Option Agreements, on December 31, 2024 the Company granted and on December 31, 2025, will grant Paruka a warrant to purchase a number of shares equal to 1.00% of outstanding shares as of the date of the grant on a fully-diluted basis, with an exercise price equal to the fair market value of the underlying shares on the grant date (the “Paruka Warrant Obligation”).

The grant dates for the issuance of warrants were expected to be December 31, 2024 and December 31, 2025 as all terms of the award, including number of shares and exercise price, will be known by all parties. The Company determined that the 2024 and 2025 grants are two separate grants, as there would be no obligation for the 2025 grant had the Company exercised or terminated all of the options under the Option Agreements prior to December 31, 2024. The service inception period for the grant precedes the grant date, with the full award being vested as of the grant date with no post-grant date service requirement. Accordingly, the warrant expected to be granted to Paruka was accounted for as a liability on the balance sheet on the service inception date and, after the initial recognition, the liability is adjusted to fair value at the end of each reporting period, with changes in fair value recorded in the consolidated statement of operations and comprehensive loss as stock-based compensation expenses under research and development expenses. Accordingly, the Company measured the grant date fair value of the warrant granted on December 31, 2024 at $10.4 million. For the period from February 6, 2024 (inception) to December 31, 2024, $10.4 million was recognized as stock-based compensation expense related to the Paruka Warrant Obligation in the consolidated statement of operations and comprehensive loss. As of December 31, 2024, there was no unamortized expense related to the December 31, 2024 Paruka Warrant Obligation. On issuance of the warrant to Paruka, the fair value of the warrant was reclassified from liability to equity on the consolidated balance sheet as of December 31, 2024.

Employee Warrants

As stated above, on July 3, 2024, the Subscription Agreement was amended and restated, among other things, for employee warrants to be issued to certain Pre-Merger Oruka employees and directors immediately prior to the closing of the Merger. Pursuant to this amendment, during the period from February 6, 2024 (inception) to December 31, 2024, the Company issued 3,054,358 warrants at an exercise price of $7.80 per warrant, which are accounted as equity in the consolidated financial statements. The employee warrants were subject to performance and service based vesting requirements and upon completion of the Merger the performance-based requirements had been achieved.

The following table summarizes the warrant activity for the period from February 6, 2024 (inception) through December 31, 2024:

	Number of Employee Warrants Outstanding		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value (in Thousands)
Balance as of February 6, 2024 (inception)		—	$	—		—	$	—
Granted		3,054,358	$	7.80
Exercised		—	$	—
Forfeited		—	$	—
Balance as of December 31, 2024		3,054,358	$	7.80		9.5	$	35,400
Vested and expected to vest, December 31, 2024		3,054,358	$	7.80		9.5	$	35,400
Exercisable, December 31, 2024		—	$	—		—	$	—

The weighted average grant-date fair value per share of warrants granted during the period from February 6, 2024 (inception) to December 31, 2024 was $6.27 per share. Aggregate intrinsic value represents the difference between the estimated fair value of the underlying Company Common Stock and the exercise price of outstanding, in-the-money warrants.

The following table summarizes the weighted-average assumptions used in calculating the fair value of the warrants for the period from February 6, 2024 (inception) to December 31, 2024:

	Period from February 6, 2024 (Inception) to December 31, 2024
Expected term (in years)		6.1
Expected volatility		99.02	%
Risk-free interest rate		4.15	%
Expected dividend yield		—

Stock-Based Compensation Expense

The following table summarizes the classification of the Company’s stock-based compensation expense in the consolidated statement of operations and comprehensive loss (in thousands):

	Period from February 6, 2024 (Inception) to December 31, 2024
Research and development	$	11,992
General and administrative		2,927
Total	$	14,919

As of December 31, 2024, total unrecognized compensation cost related to the unvested stock options was $12.7 million, which is expected to be recognized over a weighted average period of approximately 3.2 years. As of December 31, 2024, total unrecognized compensation cost related to the unvested RSAs was less than $0.1 million, which is expected to be recognized over a weighted average period of 3.1 years. As of December 31, 2024, the unrecognized compensation cost related to the employee warrants was $16.3 million, which is expected to be recognized over a weighted average period of 3.3 years.

The following table summarizes the award types of the Company’s stock-based compensation expense in the consolidated statement of operations and comprehensive loss (in thousands):

	Period from February 6, 2024 (Inception) to December 31, 2024
Paruka Warrant Obligation	$	10,357
Employee warrants		2,899
Stock options		1,626
Employee stock purchase plan		37
Total	$	14,919

Commitment and Contingencies (Details) - USD ($)	11 Months Ended
Commitment and Contingencies (Details) - USD ($)	Dec. 31, 2024	Jun. 15, 2024	Feb. 06, 2024
Commitment and Contingencies [Line Items]
Operating lease right-of-use assets	$ 876,000
Operating lease liability, current	213,000
Operating lease liability, noncurrent	$ 755,000
Lease discount rate	17.95%
Variable lease expense	$ 300,000
Non-refundable license fee	$ 150,000
California [Member]
Commitment and Contingencies [Line Items]
Lease term		39 months 15 days
Remaining lease term	33 months

Income Taxes - Schedule of Net Deferred Tax Assets (Details) $ in Thousands	11 Months Ended
	Dec. 31, 2024 USD ($)
Schedule of Net Deferred Tax Assets [Abstract]
Beginning balance
Change in valuation allowance	21,317
Ending balance	$ 21,317

Option Agreements and License Agreements (Details) - USD ($) $ in Millions	11 Months Ended	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Option Agreements and License Agreements [Line Items]
Expenses	$ 42.0
Regulatory Milestones Member [Member]
Option Agreements and License Agreements [Line Items]
Non-refundable milestone payments	$ 10.0
Paruka Warrant Obligation [Member]
Option Agreements and License Agreements [Line Items]
Warrant purchase percentage	1.00%
Paragon [Member] \| Clinical Development Milestones [Member]
Option Agreements and License Agreements [Line Items]
Non-refundable milestone payments	$ 12.0
Paragon [Member] \| Regulatory Milestones Member [Member]
Option Agreements and License Agreements [Line Items]
Non-refundable milestone payments	$ 10.0
Paragon [Member] \| Antibody Products [Member]
Option Agreements and License Agreements [Line Items]
Royalty payable on product sales, description	low single-digit percentage royalty for antibody products
Nomination Of A Development Candidate [Member] \| Paragon [Member]
Option Agreements and License Agreements [Line Items]
Non-refundable milestone payments	$ 1.5
ORKA-001 License Agreement [Member] \| Paragon [Member] \| Clinical Development Milestones [Member]
Option Agreements and License Agreements [Line Items]
Non-refundable milestone payments	12.0
ORKA-002 License Agreement [Member] \| Paragon [Member] \| Clinical Development Milestones [Member]
Option Agreements and License Agreements [Line Items]
Non-refundable milestone payments	$ 12.0
ORKA-001 [Member]
Option Agreements and License Agreements [Line Items]
Development costs, percentage	50.00%
Research and development expenses	$ 13.5
ORKA-001 [Member] \| Paragon [Member]
Option Agreements and License Agreements [Line Items]
Initiation fee	0.8
ORKA-001 [Member] \| Paragon [Member] \| First Dosing of Human Patient in Phase1Trial Milestone [Member]
Option Agreements and License Agreements [Line Items]
Non-refundable milestone payments	2.5
ORKA-001 [Member] \| Related Party [Member]
Option Agreements and License Agreements [Line Items]
Accounts payable and other current liabilities	2.8
ORKA-001 [Member] \| Research and Development Expense [Member] \| Paragon [Member] \| First Dosing of Human Patient in Phase1Trial Milestone [Member]
Option Agreements and License Agreements [Line Items]
Milestone consideration paid	2.5
ORKA-001 [Member] \| Research and Development Expense [Member] \| Paragon [Member] \| Achievement Of Development Candidate [Member]
Option Agreements and License Agreements [Line Items]
Milestone consideration paid	$ 1.5
ORKA-002 [Member] \| Paruka Warrant Obligation [Member]
Option Agreements and License Agreements [Line Items]
Warrant purchase percentage	1.00%
ORKA-002 [Member] \| Paragon [Member]
Option Agreements and License Agreements [Line Items]
Research and development expenses	$ 7.8
Development costs		$ 3.3
Research initial fees	0.8
ORKA-002 [Member] \| Paragon [Member] \| First Dosing of Human Patient in Phase1Trial Milestone [Member]
Option Agreements and License Agreements [Line Items]
Non-refundable milestone payments	2.5
ORKA-002 [Member] \| Related Party [Member]
Option Agreements and License Agreements [Line Items]
Accounts payable and other current liabilities	2.7
ORKA-002 [Member] \| Research and Development Expense [Member] \| Paragon [Member] \| Achievement Of Development Candidate [Member]
Option Agreements and License Agreements [Line Items]
Milestone consideration paid	$ 1.5

Option Agreements and License Agreements

11 Months Ended

Dec. 31, 2024

Option Agreements and License Agreements [Abstract]

Option Agreements and License Agreements

12. Option Agreements and License Agreements

In March 2024, the Company entered into two antibody discovery and option agreements (“Option Agreements”) with Paragon and Paruka. Under the terms of each agreement, Paragon identifies, evaluates, and develops antibodies directed against certain mutually agreed therapeutic targets of interest to the Company. From time to time, the Company can choose to add additional targets to the collaboration upon agreement with Paragon and Paruka. Under the Option Agreements, the Company has the exclusive option to, on a research program-by-research program basis, be granted an exclusive, worldwide license to all of Paragon’s right, title, and interest in and to the intellectual property resulting from the applicable research program to develop, manufacture, and commercialize the antibodies and products directed to the selected target(s) (each, an “Option”). The Company has initiated certain research programs with Paragon that generally focus on discovering, generating, identifying and/or characterizing antibodies directed to a particular target (each, a “Research Program”), including for IL-23 and IL-17A/F for ORKA-001 and ORKA-002, respectively. The exclusive option with respect to each Research Program is exercisable at the Company’s sole discretion at such time as specified in the Option Agreements (the “Option Period”). There is no payment due upon exercise of an Option pursuant to the Option Agreements. For each of these agreements, once the Company enters into the corresponding license agreements, it will be required to make non-refundable milestone payments to Paragon of up to $12.0 million under each respective agreement upon the achievement of certain clinical development milestones, up to $10.0 million under each respective agreement upon the achievement of certain regulatory milestones, as well as a low single-digit percentage royalty for antibody products beginning on the first commercial sale in each program.

The Company may terminate any Option Agreement or any Research Program at any time for any or no reason upon 30 days’ prior written notice to Paragon, provided that it must pay certain unpaid fees due to Paragon upon such termination, as well as any non-cancellable obligations reasonably incurred by Paragon in connection with its activities under any terminated Research Program. Paragon may terminate any Option Agreement or a Research Program immediately upon written notice to the Company if, as a result of any action or failure to act by the Company or its affiliates, such Research Program or all material activities under the applicable Research Plan are suspended, discontinued or otherwise delayed for a certain consecutive number of months. Each party has the right to terminate the Option Agreements or any Research Program upon material breach that remains uncured or the other party’s bankruptcy.

Paragon Therapeutics – License Agreements

In September 2024, the Company exercised the Option to acquire certain rights to ORKA-001, and in December 2024, it entered into the corresponding license agreement with Paragon (the “ORKA-001 License Agreement”), pursuant to which Paragon granted the Company a royalty-bearing, world-wide, exclusive license to develop, manufacture, commercialize or otherwise exploit certain antibodies and products targeting IL-23 in all fields other than the field of inflammatory bowel disease (“ORKA-001 Field”). In December 2024, the Company exercised the Option with respect to ORKA-002 for the IL-17A/F program, and in February 2025, it entered into the corresponding license agreement with Paragon (the “ORKA-002 License Agreement” and together with the ORKA-001 License Agreement, the “License Agreements”), pursuant to which Paragon granted the Company a royalty-bearing, world-wide, exclusive license to develop, manufacture, commercialize or otherwise exploit certain antibodies and products targeting IL-17A/F in all fields (“ORKA-002 Field” and together with the ORKA-001 Field, the “Fields”).

The License Agreements provide the Company with exclusive licenses in the Fields to Paragon’s patent applications covering the related antibodies, their method of use and their method of manufacture and Paragon has agreed not to conduct any new campaigns that generate anti-IL-23 monospecific antibodies or anti-IL-17A/F monospecific antibodies for the ORKA-001 Field or the ORKA-002 Field, respectively, for at least five years. Each of the ORKA-001 and ORKA-002 License Agreements may be terminated on 60 days’ notice to Paragon, on material breach without cure, and on a party’s insolvency or bankruptcy to the extent permitted by law.

Pursuant to the terms of each of the ORKA-001 and ORKA-002 License Agreements, the Company is obligated to pay Paragon non-refundable milestone payments of up to $12.0 million under each respective agreement upon the achievement of certain clinical development milestones and up to $10.0 million under each respective agreement upon the achievement of certain regulatory milestones, including a $1.5 million fee for nomination of a development candidate (or initiation of an IND-enabling toxicology study) and a further milestone payment of $2.5 million upon the first dosing of a human patient in a Phase 1 trial for each of ORKA-001 and ORKA-002. In addition, the Company is obligated to pay Paragon a low single-digit percentage royalty for antibody products for each of ORKA-001 and ORKA-002. For each of the License Agreements, the royalty term ends on the later of (i) the last-to-expire licensed patent or our patent directed to the manufacture, use or sale of a licensed antibody in the country at issue or (ii) 12 years from the date of first sale of a Company product. There is also a royalty step-down if there is no Paragon patent in effect during the royalty term for each program.

Additionally, as part of the Option Agreements, on December 31, 2024 the Company granted and on December 31, 2025, will grant Paruka a warrant to purchase a number of shares equal to 1.00% of outstanding shares as of the date of the grant on a fully-diluted basis, with an exercise price equal to the fair market value of the underlying shares on the grant date.

Pursuant to the Option Agreements, on a research program-by-research program basis following the finalization of the research plan for each respective research program, the Company was required to pay Paragon a one-time, nonrefundable research initiation fee of $0.8 million related to the ORKA-001 program. This amount was recognized as a research and development expense during the period from February 6, 2024 (inception) to December 31, 2024. In June 2024, pursuant to the Option Agreements with Paragon, the Company completed the selection process of its development candidate for IL-23 antibody for ORKA-001 program. The Company was responsible for 50% of the development costs incurred through the completion of the IL-23 selection process. The Company received the rights to at least one selected IL-23 antibody in June 2024. During the period from February 6, 2024 (inception) to December 31, 2024, the Company exercised its option for ORKA-001 and recorded a $1.5 million milestone payment related to the achievement of development candidate as research and development expense in the Company’s consolidated statement of operations and comprehensive loss. In addition, during the period from February 6, 2024 (inception) to December 31, 2024, the Company recorded a $2.5 million milestone payment related to the first dosing of a human subject in a Phase 1 trial of ORKA-001 in December 2024 as research and development expense in its consolidated statement of operations and comprehensive loss. The Company’s share of development costs incurred for the period from February 6, 2024 (inception) to December 31, 2024 was $13.5 million (excluding research initiation fee and milestones), which were recorded as research and development expenses. An amount of $2.8 million related to ORKA-001 is included in related party accounts payable and other current liabilities as of December 31, 2024.

The Company was also required to reimburse Paragon $3.3 million for development costs related to ORKA-002 incurred by Paragon through December 31, 2023 and certain other development costs incurred by Paragon between January 1, 2024 and March 6, 2024 as stipulated by the Option Agreements. This amount was recognized as a research and development expense during the period from February 6, 2024 (inception) to December 31, 2024. The Company is also responsible for the development costs incurred by Paragon from January 1, 2024 through the completion of the IL-17 selection process. The Company recognized an amount of $0.8 million payable to Paragon for the research initiation fee related to ORKA-002 following the finalization of the ORKA-002 research plan. This was recognized as research and development expenses in the period from February 6, 2024 (inception) to December 31, 2024. During the period from February 6, 2024 (inception) to December 31, 2024, the Company exercised its option for ORKA-002 and recorded a $1.5 million milestone payment related to the achievement of development candidate as research and development expense in its consolidated statement of operations and comprehensive loss. The Company accounted for development costs of $7.8 million (excluding research initiation fee, milestone, and reimbursements of development costs through December 31, 2023) for the period from February 6, 2024 (inception) to December 31, 2024 as research and development expenses. An amount of $2.7 million related to ORKA-002 is included in related party accounts payable and other current liabilities as of December 31, 2024.

The Company expenses the service fees as the associated costs are incurred when the underlying services are rendered. Such amounts are classified within research and development expenses in the accompanying consolidated statement of operations and comprehensive loss.

The Company concluded that the rights obtained under the Option Agreements represent an asset acquisition whereby the underlying assets comprise in-process research and development assets with no alternative future use. The Option Agreements did not qualify as a business combination because substantially all of the fair value of the assets acquired was concentrated in the exclusive license options, which represent a group of similar identifiable assets. The research initiation fee represents a one-time cost on a research program-by-research program basis for accessing research services or resources with benefits that are expected to be consumed in the near term, therefore the amounts paid are expensed as part of research and development costs immediately. Amounts paid as reimbursements of ongoing development cost, monthly development cost fee and additional development expenses incurred by Paragon due to work completed for selected targets prior to the effective date of the Option Agreements that is associated with services being rendered under the related Research Programs are recognized as research and development expense when incurred.

For the period from February 6, 2024 (inception) to December 31, 2024, the Company recognized $42.0 million of expenses in connection with services provided by Paragon and Paruka under the Option Agreements.

Cash equivalents and Marketable Securities

11 Months Ended

Dec. 31, 2024

Cash equivalents and Marketable Securities [Abstract]

Cash Equivalents and marketable Securities

5. Cash equivalents and marketable Securities

Cash equivalents and marketable securities, which are classified as available-for-sale, consisted of the following as of December 31, 2024 (in thousands):

	December 31, 2024
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash equivalents
Money market funds	$	6,350	$	—	$	—		$	6,350
U.S. treasury securities		19,656		4		—			19,660
U.S. government agency securities		3,988		—		—			3,988
Commercial papers		22,180		—		(3	)		22,177
Total cash equivalents		52,174		4		(3	)		52,175
Marketable securities
Marketable securities, current
U.S. treasury securities		190,748		55		(11	)		190,792
U.S. government agency securities		12,967		1		(2	)		12,966
Commercial papers		34,808		3		—			34,811
Corporate debt securities		75,537		7		(40	)		75,504
Total marketable securities, current		314,060		66		(53	)		314,073
Marketable securities, long-term
U.S. treasury securities		13,639		—		(32	)		13,607
U.S. government agency securities		4,485		—		(23	)		4,462
Total marketable securities, long-term		18,124		—		(55	)		18,069
Total cash equivalents and marketable securities	$	384,358	$	70	$	(111	)	$	384,317

	December 31, 2024
	Less than 12 months					12 months or longer				Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Cash equivalents
Commercial papers	$	18,199	$	(3	)	$	—	$	—	$	18,199	$	(3	)
Marketable securities
Marketable securities, current
U.S. treasury securities		49,904		(11	)		—		—		49,904		(11	)
U.S. government agency securities		4,713		(2	)		—		—		4,713		(2	)
Corporate debt securities		39,468		(40	)		—		—		39,468		(40	)
Marketable securities, long-term											—		—
U.S. treasury securities		13,607		(32	)		—		—		13,607		(32	)
U.S. government agency securities		4,462		(23	)		—		—		4,462		(23	)
Total	$	130,353	$	(111	)	$	—	$	—	$	130,353	$	(111	)

The Company evaluated its securities for credit losses and considered the decline in market value to be primarily attributable to current economic and market conditions and not to a credit loss or other factors. Additionally, the Company does not intend to sell the securities in an unrealized loss position and it is not more likely than not that the Company will be required to sell the securities before recovery of the unamortized cost basis, which may be at maturity. There were no material realized gains or realized losses on marketable securities for the period presented. Given the Company’s intent and ability to hold such securities until recovery, and the lack of significant change in credit risk of these investments, the Company does not consider these marketable securities to be impaired as of December 31, 2024. As of December 31, 2024, the Company did not record an allowance for credit losses.

The following table summarizes the contractual maturities of the Company’s marketable securities at estimated fair value (in thousands):

	December 31, 2024
Due in one year or less	$	314,073
Due in 1-2 years		18,069
Total	$	332,142

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Feb. 06, 2024
Schedule of Accrued Expenses and Other Current Liabilities [Abstract]
Accrued employee compensation and benefits	$ 2,041
Accrued professional and consulting	221
Accrued research and development	1,084
Total	$ 3,346

Related Party Transactions (Details)	11 Months Ended
Related Party Transactions (Details)	Dec. 31, 2024
Fairmount's Ownership Interest in Paragon [Member]
Related Party Transactions [Line Items]
Ownership percentage	beneficially owns more than 5%
Common Stock [Member] \| Paragon [Member]
Related Party Transactions [Line Items]
Ownership percentage	beneficially own less than 5%
Common Stock [Member] \| Paruka [Member]
Related Party Transactions [Line Items]
Ownership percentage	beneficially own less than 5%
Common Stock [Member] \| Fairmount [Member]
Related Party Transactions [Line Items]
Ownership percentage	beneficially owns more than 5%

Convertible Preferred Stock and Stockholders’ Equity - Schedule of Convertible Preferred Stock (Details) - Series B Convertible Preferred Stock [Member] $ in Thousands	Dec. 31, 2024 USD ($) shares
Schedule of Convertible Preferred Stock [Line Items]
Preferred Stock Authorized	251,504
Preferred Stock Issued	137,138
Preferred Stock Outstanding	137,138
Carrying Value (in Dollars) \| $	$ 2,931
Common Stock Issuable Upon Conversion	11,428,149

Fair Value Measurements

11 Months Ended

Dec. 31, 2024

Fair Value Measurements [Abstract]

Fair Value Measurements

4. Fair Value Measurements

The following tables present the Company’s fair value hierarchy for financial assets measured as of December 31, 2024 (in thousands):

	December 31, 2024
	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds	$	6,350	$	—	$	—	$	6,350
U.S. treasury securities		—		19,660		—		19,660
U.S. government agency securities		—		3,988		—		3,988
Commercial papers		—		22,177		—		22,177
Total cash equivalents		6,350		45,825		—		52,175
Marketable securities
Marketable securities, current
U.S. treasury securities		—		190,792		—		190,792
U.S. government agency securities		—		12,966		—		12,966
Commercial papers		—		34,811		—		34,811
Corporate debt securities		—		75,504		—		75,504
Total marketable securities, current		—		314,073		—		314,073
Marketable securities, long-term
U.S. treasury securities		—		13,607		—		13,607
U.S. government agency securities		—		4,462		—		4,462
Total marketable securities, long-term		—		18,069		—		18,069
Total cash equivalents and marketable securities	$	6,350	$	377,967	$	—	$	384,317

There were no transfers in or out of Level 3 during the period from February 6, 2024 (inception) to December 31, 2024.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 107
-Publisher FASB
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+ Details

Income Taxes (Details) $ in Thousands	11 Months Ended
Income Taxes (Details) $ in Thousands	Dec. 31, 2024 USD ($)
Income Taxes (Details) [Line Items]
Provision for income taxes
Change in valuation allowance due to continuing loss from operations	21,300
Net operating loss carryforwards	$ 10,800
Operating loss carryforwards as a percentage of taxable income	80.00%
Tax credit carryforwards	$ 3,080
Domestic Tax Jurisdiction [Member]
Income Taxes (Details) [Line Items]
Tax credit carryforwards	3,800
State and Local Jurisdiction [Member]
Income Taxes (Details) [Line Items]
Tax credit carryforwards	$ 400

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 270
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
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-SubTopic 10
-Topic 235
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

+ Details

Subsequent Events

11 Months Ended

Dec. 31, 2024

Subsequent Events [Abstract]

Subsequent Events

16. Subsequent Events

In February 2025, the Company entered into a lease agreement for an office space located in Waltham, Massachusetts. The lease is for an initial period of 54 months. The Company expects to pay approximately $1.6 million over the lease term.

Related Party Transactions - Schedule of Related Party Accounts Payable and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Feb. 06, 2024
Paragon reimbursable Option Agreements’ fees [Member]
Schedule of Related Party Accounts Payable and Other Current Liabilities [Line Items]
Related party accounts payable and other current liabilities	$ 1,482
Paragon milestone payments for Option Agreement [Member]
Schedule of Related Party Accounts Payable and Other Current Liabilities [Line Items]
Related party accounts payable and other current liabilities	4,000
Paragon reimbursable other research expenses [Member]
Schedule of Related Party Accounts Payable and Other Current Liabilities [Line Items]
Related party accounts payable and other current liabilities	515
Paragon reimbursable patent expenses [Member]
Schedule of Related Party Accounts Payable and Other Current Liabilities [Line Items]
Related party accounts payable and other current liabilities	25
Related Party [Member]
Schedule of Related Party Accounts Payable and Other Current Liabilities [Line Items]
Related party accounts payable and other current liabilities	$ 6,022

Income Taxes - Schedule of Statutory Federal Income Tax Rate to Income Before Income Taxes (Details)	11 Months Ended
	Dec. 31, 2024
Schedule of Statutory Federal Income Tax Rate to Income Before Income Taxes [Abstract]
Tax benefit derived by applying the federal statutory rate to income before income taxes	(21.00%)
Permanent differences	(0.18%)
Research and development credits	(3.41%)
Other	(0.87%)
Change in the valuation allowance	25.46%
Income tax (benefit) expense	0.00%

Pay vs Performance Disclosure $ in Thousands	11 Months Ended
Pay vs Performance Disclosure $ in Thousands	Dec. 31, 2024 USD ($)
Pay vs Performance Disclosure
Net Income (Loss)	$ (83,724)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

Nature of the Business and Basis of Presentation (Details)
$ / shares in Units, $ in Thousands

1 Months Ended

11 Months Ended

Sep. 03, 2024

$ / shares

Apr. 03, 2024

USD ($)

Sep. 30, 2024

$ / shares

Dec. 31, 2024

USD ($)

$ / shares

Feb. 06, 2024

$ / shares

Nature of the Business and Basis of Presentation [Line Items]

Common stock, par value (in Dollars per share) | $ / shares

$ 0.001

Additional paid-in capital transaction costs (in Dollars) | $

$ 20,500

Pre-funded warrants of common stock shares | shares

5,522,207

Warrants exchange | shares

9,664,208

Net loss (in Dollars) | $

$ (83,724)

Net cash operating activities (in Dollars) | $

(57,837)

Cash, cash equivalents, and marketable securities (in Dollars) | $

393,700

Pre-funded Warrants [Member]

Nature of the Business and Basis of Presentation [Line Items]

Aggregate gross proceeds (in Dollars) | $

$ 188,700

Purchase price per share (in Dollars per share) | $ / shares

$ 22.999

Net of issuance costs (in Dollars) | $

$ 11,900

Series B Preferred Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Conversion ratio

83:3332:1

Net loss (in Dollars) | $

^[1]

$ (16,769)

Common Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Investors shares | shares

22,784,139

Exchange shares | shares

4,764,032

Issuance of shares | shares

2,722,207

Prefunded warrants to purchase an aggregate shares | shares

680,000

Series A Non-Voting Convertible Preferred Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Purchase price per share (in Dollars per share) | $ / shares

$ 23,000

Series A Preferred Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Purchase price per share (in Dollars per share) | $ / shares

$ 23,000

Net loss (in Dollars) | $

^[2]

$ (1,918)

Common Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Net loss (in Dollars) | $

$ (65,037)

Common Stock [Member] | Series A Preferred Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Convertible shares | shares

1,000

Oruka Common Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Reverse stock split

1-for-12

Common stock, par value (in Dollars per share) | $ / shares

$ 0.001

Pre-Merger Oruka [Member] | Pre-funded Warrants [Member]

Nature of the Business and Basis of Presentation [Line Items]

Aggregate gross proceeds (in Dollars) | $

275,000

Proceeds from Issuance of convertible note (in Dollars) | $

$ 25,000

Pre-Merger Oruka [Member] | Common Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Exchange shares | shares

39,873,706

ARCA common stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Exchange ratio

6.8569

Oruka Series A Convertible Preferred Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Common stock, par value (in Dollars per share) | $ / shares

$ 0.0001

Series A Non-Voting Convertible Preferred Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Common stock, par value (in Dollars per share) | $ / shares

$ 0.001

PIPE Financing [Member] | Common Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Aggregate of purchased shares | shares

5,600,000

Purchase price per share (in Dollars per share) | $ / shares

$ 23

PIPE Financing [Member] | Series A Non-Voting Convertible Preferred Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Common stock, par value (in Dollars per share) | $ / shares

$ 0.001

Aggregate shares | shares

2,439

PIPE Financing [Member] | Series A Preferred Stock [Member]

Nature of the Business and Basis of Presentation [Line Items]

Exchange shares | shares

2,439

[1]	The weighted-average number of shares of as-converted Company Series B Preferred Stock used in the loss allocation was 4,328,844 for the period from February 6, 2024 (inception) to December 31, 2024.
[2]	The weighted-average number of shares of as-converted Company Series A Preferred Stock used in the loss allocation was 495,191 for the period from February 6, 2024 (inception) to December 31, 2024.

Related Party Transactions (Tables)

11 Months Ended

Dec. 31, 2024

The following is a summary of related party accounts payable and other current liabilities (in thousands):

	December 31, 2024
Paragon reimbursable Option Agreements’ fees	$	1,482
Paragon milestone payments for Option Agreement		4,000
Paragon reimbursable other research expenses		515
Paragon reimbursable patent expenses		25
Total	$	6,022

Audit Information	11 Months Ended
Audit Information	Dec. 31, 2024
Auditor [Table]
Auditor Name	PricewaterhouseCoopers LLP
Auditor Firm ID	238
Auditor Location	Boston, Massachusetts
Auditor Opinion [Text Block]	Opinion on the Financial Statements We have audited the accompanying consolidated balance sheets of Oruka Therapeutics, Inc. and its subsidiaries (the “Company”) as of December 31, 2024 and February 6, 2024, and the related consolidated statements of operations and comprehensive loss, of convertible preferred stock and stockholders’ equity and of cash flows for the period from February 6, 2024 (inception) to December 31, 2024, including the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2024 and February 6, 2024, and the results of its operations and its cash flows for the period from February 6, 2024 (inception) to December 31, 2024 in conformity with accounting principles generally accepted in the United States of America.

Stock-Based Compensation (Details) - USD ($)		11 Months Ended
Stock-Based Compensation (Details) - USD ($)	Aug. 29, 2024	Dec. 31, 2024	Aug. 22, 2024	Feb. 06, 2024
Stock-Based Compensation [Line Items]
Shares reserved for future issuance		27,556,257
Common stock, shares issued		37,440,510		3,197,975
Stock-based compensation expense		$ 14,919,000
Estimated fair value of warrants to be granted		$ 10,400,000
Stock Options [Member]
Stock-Based Compensation [Line Items]
Shares reserved for future issuance		1,567,760
Weighted average grant-date fair value		$ 9.12
Total unrecognized compensation cost		$ 12,700,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition		3 years 2 months 12 days
2024 Stock Incentive Plan [Member]
Stock-Based Compensation [Line Items]
Shares available for grant		4,246,324
Annual increase in shares available for issuance as a percentage of outstanding diluted stock		5.00%
RSA [Member]
Stock-Based Compensation [Line Items]
Common stock, shares issued		2,207,553
Stock-based compensation expense		$ 100,000
RSAs issued		2,207,553
RSAs price per share		$ 0.0001
Total unrecognized compensation cost		$ 100,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition		3 years 1 month 6 days
Paruka Warrant Obligation [Member]
Stock-Based Compensation [Line Items]
Shares reserved for future issuance		596,930
Stock-based compensation expense		$ 10,400,000
Warrant To Purchase Number Of Shares As A Percentage Of Outstanding Diluted Stock		1.00%
Employee Warrants [Member]
Stock-Based Compensation [Line Items]
Shares reserved for future issuance		3,054,358
Warrants issued		3,054,358
Exercise price per warrant		$ 7.8
Price per share		$ 6.27
Total unrecognized compensation cost		$ 16,300,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition		3 years 3 months 18 days
2024 Stock Incentive Plan [Member]
Stock-Based Compensation [Line Items]
Shares available for grant			4,634,891
Shares reserved for future issuance		4,246,324
2024 Stock Incentive Plan [Member] \| Stock Options [Member]
Stock-Based Compensation [Line Items]
Shares reserved for future issuance		388,567
2024 Employee Stock Purchase Plan [Member]
Stock-Based Compensation [Line Items]
Shares available for grant		460,529
Shares reserved for future issuance	463,489	460,529
Annual increase in shares available for issuance as a percentage of outstanding diluted stock		1.00%
Purchase price of common stock expressed as a percentage of its fair value	85.00%
Maximum contribution of employee's eligible compensation	15.00%
Total amount of annual salary that an employee is permitted to utilize to purchase company shares under ESPP	$ 25,000
Common stock, shares issued		2,960
Stock-based compensation expense		$ 100,000

Commitment and Contingencies - Schedule of Company’s Supplemental Cash Flow Information Related to Leases (Details) $ in Thousands	11 Months Ended
	Dec. 31, 2024 USD ($)
Schedule of Company’s Supplemental Cash Flow Information Related to Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities	$ 116

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Dec. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Accrued Expenses and Other Current Liabilities

11 Months Ended

Dec. 31, 2024

Accrued Expenses and Other Current Liabilities [Abstract]

Accrued Expenses and Other Current Liabilities

6. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):

	December 31, 2024
Accrued employee compensation and benefits	$	2,041
Accrued professional and consulting		221
Accrued research and development		1,084
Total	$	3,346

Summary of Significant Accounting Policies

11 Months Ended

Dec. 31, 2024

Summary of Significant Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Use of Estimates

Concentrations of Credit Risk and Other Risks and Uncertainties

Cash and Cash Equivalents

Marketable Securities

Debt Issuance Costs

Subscription Receivable

Fair Value Measurements

●

Level 1 — Quoted prices in active markets that are identical assets or liabilities.

●

Property and Equipment

Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset as follows:

		Estimated Useful Life
Furniture and fixtures		3-5 years
Computer and office equipment		3-5 years

Classification of Convertible Preferred Stock

Note Payable to Related Party

Research and Development Contract Costs Accruals

Leases

Segment Reporting

Research and Development Costs

General and Administrative Expenses

Commitments and Contingencies

Stock-Based Compensation

The Company has issued stock options, warrants, and RSAs with service-based and performance-based vesting conditions.

Comprehensive Loss

Net Loss per Share Attributable to Stockholders

Other income, net

Income Taxes

Recently Adopted Accounting Pronouncements

Recently Issued Accounting Pronouncements

Commitment and Contingencies

11 Months Ended

Dec. 31, 2024

Commitment and Contingencies [Abstract]

Commitment and Contingencies

13. Commitment and Contingencies

Leases

In April 2024, the Company entered into an operating lease agreement for the Company’s headquarters in Menlo Park, California, which commenced on June 15, 2024 with an initial term of 39.5 months. The Company leases office space under this noncancelable operating lease agreement. Lease liabilities are based on the net present value of the remaining lease payments over the remaining lease term. In determining the present value of lease payments, the Company used its incremental borrowing rate when measuring operating lease liabilities as discount rates were not implicit or readily determinable.

As of December 31, 2024, the Company had $0.9 million of operating lease right-of-use assets, operating lease liability, current of $0.2 million, and operating lease liability, noncurrent of $0.8 million on its consolidated balance sheet. As of December 31, 2024, the operating lease arrangement had a remaining lease term of 33 months and a discount rate of 17.95%. For the period from February 6, 2024 (inception) to December 31, 2024, the Company recorded operating and variable lease expense of $0.3 million in general and administrative expenses in its consolidated statement of operations and comprehensive loss.

The following table presents the Company’s supplemental cash flow information related to leases (in thousands):

		Period from February 6, 2024 (Inception) to December 31, 2024
Cash paid for amounts included in the measurement of lease liabilities		$	116

The following table summarizes a maturity analysis of the Company’s operating lease liabilities showing the aggregate lease payments as of December 31, 2024 (in thousands):

Year ending December 31,	Amount
2025	$	369
2026		494
2027		380
Total undiscounted lease payments		1,243
Less: imputed interest		(275	)
Total discounted lease payments		968
Less: current portion of lease liability		(213	)
Non-current portion of lease liability	$	755

Cell Line License Agreement

In March 2024, the Company entered into the Cell Line License Agreement (the “Cell Line License Agreement”) with WuXi Biologics Ireland Limited (“WuXi Biologics”). Under the Cell Line License Agreement, the Company received a non-exclusive, worldwide, sublicensable license to certain of WuXi Biologics’ know-how, cell line, biological materials (the “WuXi Biologics Licensed Technology”) and media and feeds to make, have made, use, sell and import certain therapeutic products produced through the use of the cell line licensed by WuXi Biologics under the Cell Line License Agreement (the “WuXi Biologics Licensed Products”). Specifically, the WuXi Biologics Licensed Technology is used in certain manufacturing activities in support of the ORKA-001 and ORKA-002 programs.

In consideration for the license, the Company agreed to pay WuXi Biologics a non-refundable license fee of $150,000, which was recognized as a research and development expense during the period from February 6, 2024 (inception) to December 31, 2024. Additionally, to the extent that the Company manufactures its commercial supplies of bulk drug product with a manufacturer other than WuXi Biologics or its affiliates, the Company is required to make royalty payments to WuXi Biologics at a rate of less than one percent of net sales of WuXi Biologics Licensed Products manufactured by the third-party manufacturer. Pursuant to an amendment to the Cell Line License Agreement effective in November 2024, a provision was added that permits the royalties owed under the agreement to be bought out on a product-by-product basis for a lump-sum payment.

The Cell Line License Agreement will continue indefinitely unless terminated (i) by the Company upon six months’ prior written notice and its payment of all undisputed amounts due to WuXi Biologics through the effective date of termination, (ii) by WuXi Biologics for a material breach by the Company that remains uncured for 60 days after written notice, (iii) by WuXi Biologics if the Company fails to make a payment and such failure continues for 30 days after receiving notice of such failure, or (iv) by either party upon the other party’s bankruptcy.

Accrued Expenses and Other Current Liabilities (Tables)

11 Months Ended

Dec. 31, 2024

Accrued Expenses and Other Current Liabilities [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):

	December 31, 2024
Accrued employee compensation and benefits	$	2,041
Accrued professional and consulting		221
Accrued research and development		1,084
Total	$	3,346

Stock-Based Compensation - Schedule of Company’s Stock-Based Compensation Expense (Details) $ in Thousands	11 Months Ended
	Dec. 31, 2024 USD ($)
Schedule of Company’s Stock-Based Compensation Expense [Line Items]
Stock-based compensation expense	$ 14,919
Research and development [Member]
Schedule of Company’s Stock-Based Compensation Expense [Line Items]
Stock-based compensation expense	11,992
General and administrative [Member]
Schedule of Company’s Stock-Based Compensation Expense [Line Items]
Stock-based compensation expense	$ 2,927

Note Payable with Related Party (Details) - Convertible Note [Member] - USD ($) $ in Millions	1 Months Ended	11 Months Ended
	Mar. 31, 2024	Dec. 31, 2024
Note Payable with Related Party [Line Items]
Interest expense		$ 1.5
Pre-Merger Oruka [Member]
Note Payable with Related Party [Line Items]
Initial principal amount	$ 25.0
Interest rate, percentage	12.00%
Maturity date	Dec. 31, 2025
Debt issuance costs		0.1
Unpaid accrued interest		$ 1.5
Pre-Merger Oruka [Member] \| Fairmount Healthcare Fund II, L.P. [Member]
Note Payable with Related Party [Line Items]
Initial principal amount	$ 25.0
Aggregate proceeds	$ 25.0
Common Stock [Member]
Note Payable with Related Party [Line Items]
Converted shares (in Shares)		2,722,207

Fair Value Measurements (Tables)

11 Months Ended

Dec. 31, 2024

Fair Value Measurements [Abstract]

Schedule of Fair Value Hierarchy for Financial Assets Measured

The following tables present the Company’s fair value hierarchy for financial assets measured as of December 31, 2024 (in thousands):

	December 31, 2024
	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds	$	6,350	$	—	$	—	$	6,350
U.S. treasury securities		—		19,660		—		19,660
U.S. government agency securities		—		3,988		—		3,988
Commercial papers		—		22,177		—		22,177
Total cash equivalents		6,350		45,825		—		52,175
Marketable securities
Marketable securities, current
U.S. treasury securities		—		190,792		—		190,792
U.S. government agency securities		—		12,966		—		12,966
Commercial papers		—		34,811		—		34,811
Corporate debt securities		—		75,504		—		75,504
Total marketable securities, current		—		314,073		—		314,073
Marketable securities, long-term
U.S. treasury securities		—		13,607		—		13,607
U.S. government agency securities		—		4,462		—		4,462
Total marketable securities, long-term		—		18,069		—		18,069
Total cash equivalents and marketable securities	$	6,350	$	377,967	$	—	$	384,317

Net Loss Per Share - Schedule of Anti-Dilutive Effect Excluded from Potential Computation of Diluted Net Loss Per Share (Details)	11 Months Ended
	Dec. 31, 2024 shares
Schedule of Anti-Dilutive Effect Excluded from Potential Computation of Diluted Net Loss Per Share [Line Items]
Total anti-dilutive securities	7,426,601
Employee Warrants [Member]
Schedule of Anti-Dilutive Effect Excluded from Potential Computation of Diluted Net Loss Per Share [Line Items]
Total anti-dilutive securities	3,054,358
Restricted Stock Awards [Member]
Schedule of Anti-Dilutive Effect Excluded from Potential Computation of Diluted Net Loss Per Share [Line Items]
Total anti-dilutive securities	2,207,553
Stock Options [Member]
Schedule of Anti-Dilutive Effect Excluded from Potential Computation of Diluted Net Loss Per Share [Line Items]
Total anti-dilutive securities	1,567,760
Paruka Warrant [Member]
Schedule of Anti-Dilutive Effect Excluded from Potential Computation of Diluted Net Loss Per Share [Line Items]
Total anti-dilutive securities	596,930

Consolidated Statement of Cash Flows $ in Thousands	11 Months Ended
Consolidated Statement of Cash Flows $ in Thousands	Dec. 31, 2024 USD ($)
Cash flows from operating activities:
Net loss	$ (83,724)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	14,919
Net accretion of premiums and discounts on marketable securities	(2,245)
Non-cash interest expense	1,468
Non-cash lease expense	127
Depreciation expense	27
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(1,128)
Other non-current assets	(43)
Accounts payable	3,462
Accrued expenses and other current liabilities	3,292
Operating lease liability	(14)
Related party accounts payable and other current liabilities	6,022
Net cash used in operating activities	(57,837)
Cash flows from investing activities:
Purchases of property and equipment	(189)
Purchases of marketable securities	(329,938)
Net cash used in investing activities	(330,127)
Cash flows from financing activities:
Proceeds from issuance of Pre-Merger Oruka Series A Preferred Stock, net of issuance costs paid	2,931
Proceeds from issuance of notes payable to related party, net of issuance costs paid	24,980
Proceeds from the Pre-Closing Financing, net	227,953
Proceeds from the PIPE Financing, net	188,681
Cash acquired in connection with the reverse recapitalization	4,940
Proceeds from issuance of common stock	54
Net cash provided by financing activities	449,539
Net increase in cash and cash equivalents	61,575
Cash at beginning of period
Cash and cash equivalents at end of period	61,575
Supplemental disclosures of non-cash operating and financing activities:
Operating lease liability arising from obtaining operating right-of-use asset	982
Assets acquired in connection with the reverse capitalization	114
Other liabilities assumed in connection with the reverse recapitalization	(54)
Non-cash accrued interest on convertible note converted to common stock	1,468
Non-cash exchange of Pre-Merger Oruka Series A preferred stock for Series B convertible preferred stock	2,931
Conversion of Series A non-voting convertible preferred stock to common stock	52,834
Reclassification of the Paruka warrant from liability to equity	$ 10,357

Consolidated Balance Sheets (Parentheticals) - $ / shares	Dec. 31, 2024	Feb. 06, 2024
Common stock, par value (in Dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	545,000,000	65,000,000
Common stock, shares issued	37,440,510	3,197,975
Common stock, shares outstanding	37,440,510	3,197,975
Series A Convertible Preferred Stock
Convertible preferred stock, par value (in Dollars per share)	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized		20,000,000
Convertible preferred stock, shares issued
Convertible preferred stock, shares outstanding
Series A Non-Voting Convertible Preferred Stock
Convertible preferred stock, par value (in Dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized
Convertible preferred stock, shares issued
Convertible preferred stock, shares outstanding
Series B Non-Voting Convertible Preferred Stock
Non-voting convertible preferred stock, par value (in Dollars per share)	$ 0.001	$ 0.001
Non-voting convertible preferred stock, shares authorized	251,504
Non-voting convertible preferred stock, shares issued	137,138
Non-voting convertible preferred stock, shares outstanding	137,138

Net Loss Per Share (Tables)

11 Months Ended

Dec. 31, 2024

Net Loss per Share [Abstract]

Schedule of Basic and Diluted Net Loss Per Share Attributable to Stockholders

Basic and diluted net loss per share attributable to stockholders were calculated as follows (in thousands, except share and per share data):

	Period from February 6, 2024 (Inception) to December 31, 2024
	Loss Allocation			Weighted Average Shares Outstanding		Loss Per Share, Basic and Diluted
Common Stock	$	(65,037	)		16,789,362	$	(3.87	)
Company Series A Preferred Stock ⁽¹⁾		(1,918	)		495	$	(3,873.25	)
Company Series B Preferred Stock ⁽²⁾		(16,769	)		51,946	$	(322.81	)
Net loss	$	(83,724	)

(1)	The weighted-average number of shares of as-converted Company Series A Preferred Stock used in the loss allocation was 495,191 for the period from February 6, 2024 (inception) to December 31, 2024.

(2)	The weighted-average number of shares of as-converted Company Series B Preferred Stock used in the loss allocation was 4,328,844 for the period from February 6, 2024 (inception) to December 31, 2024.

Schedule of Anti-Dilutive Effect Excluded from Potential Computation of Diluted Net Loss Per Share

	December 31, 2024
Outstanding employee warrants to purchase common stock		3,054,358
Outstanding unvested restricted stock awards		2,207,553
Outstanding and issued common stock options		1,567,760
Outstanding and issued warrant to Paruka		596,930
Total		7,426,601

Income Taxes (Tables)

11 Months Ended

Dec. 31, 2024

Income Taxes [Abstract]

Schedule of Loss Before Income Tax Expense

The following table summarizes the loss before income tax expense by jurisdiction for the periods indicated:

	Period from February 6, 2024 (Inception) to December 31, 2024
Domestic	$	(83,724	)
Foreign		—
Loss before income tax expense	$	(83,724	)

Schedule of Statutory Federal Income Tax Rate to Income Before Income Taxes

The difference between the Company’s provision for income taxes and the amounts computed by applying the statutory federal income tax rate to income before income taxes is as follows:

	Period from February 6, 2024 (Inception) to December 31, 2024
Tax benefit derived by applying the federal statutory rate to income before income taxes		(21.00	)%
Permanent differences		(0.18	)
Research and development credits		(3.41	)
Other		(0.87	)
Change in the valuation allowance		25.46
Income tax (benefit) expense		0.00	%

Schedule of Components of the Deferred Tax Assets and Liabilities

The components of the deferred tax assets and liabilities consist of the following (in thousands):

	December 31, 2024
Deferred tax assets
Net operating loss carryforwards	$	2,260
Research and development credits		3,080
Stock-based compensation		3,063
Accruals and other		424
Lease liability		203
Intangibles		1,477
Capitalized R&D expenses		10,994
Total deferred tax assets		21,501
Deferred tax liabilities
Right- of- use asset		(184	)
Total deferred tax liabilities		(184	)
Less valuation allowance		(21,317	)
Deferred tax assets, net	$	—

Schedule of Net Deferred Tax Assets

he Company has established a full federal and state valuation allowance equal to the net deferred tax assets due to uncertainties regarding the realization of the deferred tax asset based on the Company’s lack of earnings history. The valuation allowance increased by $21.3 million primarily due to continuing loss from operations.

	December 31, 2024
Beginning balance as of February 6, 2024	$	—
Change in valuation allowance		21,317
Ending balance as of December 31, 2024	$	21,317

Schedule of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands):

	Period from February 6, 2024 (Inception) to December 31, 2024
Beginning balance as of February 6, 2024	$	—
Changes related to tax positions taken in the current year		1,047
Ending balance as of December 31, 2024	$	1,047

Cash equivalents and Marketable Securities - Schedule of Available-for-Sale Securities in an Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2024 USD ($)
Cash equivalents
Less than 12 months, Fair Value	$ 130,353
Less than 12 months, Unrealized Losses	(111)
12 months or longer, Fair Value
12 months or longer, Unrealized Losses
Fair Value	130,353
Unrealized Losses	(111)
Commercial papers [Member]
Cash equivalents
Less than 12 months, Fair Value	18,199
Less than 12 months, Unrealized Losses	(3)
12 months or longer, Fair Value
12 months or longer, Unrealized Losses
Fair Value	18,199
Unrealized Losses	(3)
Marketable securities, current [Member] \| U.S. treasury securities [Member]
Cash equivalents
Less than 12 months, Fair Value	49,904
Less than 12 months, Unrealized Losses	(11)
12 months or longer, Fair Value
12 months or longer, Unrealized Losses
Fair Value	49,904
Unrealized Losses	(11)
Marketable securities, current [Member] \| U.S. government agency securities [Member]
Cash equivalents
Less than 12 months, Fair Value	4,713
Less than 12 months, Unrealized Losses	(2)
12 months or longer, Fair Value
12 months or longer, Unrealized Losses
Fair Value	4,713
Unrealized Losses	(2)
Marketable securities, current [Member] \| Corporate debt securities [Member]
Cash equivalents
Less than 12 months, Fair Value	39,468
Less than 12 months, Unrealized Losses	(40)
12 months or longer, Fair Value
12 months or longer, Unrealized Losses
Fair Value	39,468
Unrealized Losses	(40)
Marketable securities, long-term [Member] \| U.S. treasury securities [Member]
Cash equivalents
Less than 12 months, Fair Value	13,607
Less than 12 months, Unrealized Losses	(32)
12 months or longer, Fair Value
12 months or longer, Unrealized Losses
Fair Value	13,607
Unrealized Losses	(32)
Marketable securities, long-term [Member] \| U.S. government agency securities [Member]
Cash equivalents
Less than 12 months, Fair Value	4,462
Less than 12 months, Unrealized Losses	(23)
12 months or longer, Fair Value
12 months or longer, Unrealized Losses
Fair Value	4,462
Unrealized Losses	$ (23)

Stock-Based Compensation (Tables)

11 Months Ended

Dec. 31, 2024

Stock-Based Compensation [Abstract]

Schedule of Weighted-Average Assumptions Used in Calculating the Fair Value of the Awards

The following table summarizes the weighted-average assumptions used in calculating the fair value of the awards for the period from February 6, 2024 (inception) to December 31, 2024:

	Period from February 6, 2024 (Inception) to December 31, 2024
Expected term (in years)		6.1
Expected volatility		100.21	%
Risk-free interest rate		4.26	%
Expected dividend yield		—

The following table summarizes the weighted-average assumptions used in calculating the fair value of the warrants for the period from February 6, 2024 (inception) to December 31, 2024:

	Period from February 6, 2024 (Inception) to December 31, 2024
Expected term (in years)		6.1
Expected volatility		99.02	%
Risk-free interest rate		4.15	%
Expected dividend yield		—

Schedule of Stock Option Activity

The following table summarizes the stock option activities under the 2024 Plan and 2024 Stock Plan for the period of February 6, 2024 (inception) through December 31, 2024:

	Number of Stock Options Outstanding		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value (in Thousands)
Balance as of February 6, 2024 (inception)		—	$	—		—	$	—
Granted		1,567,760	$	11.39
Exercised		—	$	—
Forfeited		—	$	—
Balance as of December 31, 2024		1,567,760	$	11.39		9.4	$	15,470
Vested and expected to vest, December 31, 2024		1,567,760	$	11.39		9.4	$	15,470
Exercisable, December 31, 2024		—	$	—		—	$	—

Schedule of RSA Activity

The following table summarizes the RSA activity for the period from February 6, 2024 (inception) through December 31, 2024:

	Number of RSAs		Weighted Average Grant Date Fair Value
Unvested balance as of February 6, 2024 (inception)		—	$	—
Granted		2,207,553	$	—
Unvested balance as of December 31, 2024		2,207,553	$	—

Schedule of Employee Warrant Activity

The following table summarizes the warrant activity for the period from February 6, 2024 (inception) through December 31, 2024:

	Number of Employee Warrants Outstanding		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value (in Thousands)
Balance as of February 6, 2024 (inception)		—	$	—		—	$	—
Granted		3,054,358	$	7.80
Exercised		—	$	—
Forfeited		—	$	—
Balance as of December 31, 2024		3,054,358	$	7.80		9.5	$	35,400
Vested and expected to vest, December 31, 2024		3,054,358	$	7.80		9.5	$	35,400
Exercisable, December 31, 2024		—	$	—		—	$	—

Schedule of Company’s Stock-Based Compensation Expense

The following table summarizes the classification of the Company’s stock-based compensation expense in the consolidated statement of operations and comprehensive loss (in thousands):

	Period from February 6, 2024 (Inception) to December 31, 2024
Research and development	$	11,992
General and administrative		2,927
Total	$	14,919

Schedule of Award Types of Company’s Stock-Based Compensation Expense

The following table summarizes the award types of the Company’s stock-based compensation expense in the consolidated statement of operations and comprehensive loss (in thousands):

	Period from February 6, 2024 (Inception) to December 31, 2024
Paruka Warrant Obligation	$	10,357
Employee warrants		2,899
Stock options		1,626
Employee stock purchase plan		37
Total	$	14,919

Net Loss Per Share (Details)	11 Months Ended
Net Loss Per Share (Details)	Dec. 31, 2024 shares
Series A Preferred Stock [Member]
Net Loss per Share [Line Items]
Weighted-average number of shares of as-converted	495,191
Series B Preferred Stock [Member]
Net Loss per Share [Line Items]
Weighted-average number of shares of as-converted	4,328,844

Segment Disclosures (Tables)

11 Months Ended

Dec. 31, 2024

Segment Disclosures [Abstract]

Schedule of Segment Loss from Operations

The table below is a summary of the segment loss from operations, including significant segment expenses (in thousands):

	Period from February 6, 2024 (Inception) to December 31, 2024
Research and development personnel-related (excluding stock-based compensation)	$	3,959
General and administrative personnel-related (excluding stock-based compensation)		5,054
Research and development stock-based compensation		11,992
General and administrative stock-based compensation		2,927
External research and development		57,680
Other research and development		1,429
General and administrative, excluding personnel-related and stock-based compensation		5,082
Total operating expenses		88,123
Loss from operations	$	(88,123	)

Convertible Preferred Stock and Stockholders’ Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			11 Months Ended
	Sep. 30, 2024	Aug. 31, 2024	Mar. 31, 2024	Dec. 31, 2024	Nov. 30, 2024	Feb. 06, 2024
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Gross proceeds (in Dollars)				$ 2,931
Common stock, shares authorized				545,000,000		65,000,000
Common stock, shares issued				37,440,510		3,197,975
Common stock, shares outstanding				37,440,510		3,197,975
Pre-Funded Warrants [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Number of shares issued	680,000	5,522,207
Purchase price per share (in Dollars per share)		$ 9.7
Warrants outstanding		5,522,207		6,202,207
Purchase price per share (in Dollars per share)	$ 22.999
Expiration date
Warrants exercised
Employee Warrants [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Warrants outstanding				3,054,358
Exercise price per warrant (in Dollars per share)				$ 7.8
Employee warrants issued				3,054,358
Vesting period				4 years
Warrants exercised
Paruka Warrant [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Exercise price per warrant (in Dollars per share)				$ 19.39
Warrant purchase				596,930
Term of warrant				10 years
Common Stock [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Warrants exercisable	680,000	5,522,207
Common stock, shares authorized				545,000,000
Common stock, shares issued				37,440,510
Common stock, shares outstanding				37,440,510
Common Stock [Member] \| Pre-Funded Warrants [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Exercise price per warrant (in Dollars per share)	$ 0.001	$ 0.01
Restricted Stock [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Purchase price per share (in Dollars per share)				$ 0.0001
Common stock, shares issued				2,207,553
Common stock, shares outstanding				2,207,553
Series A Preferred Stock [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Purchase price per share (in Dollars per share)	$ 23,000
Converted shares					2,439,000
Preferred stock, shares outstanding
Converted shares of common stock					1,000
Series A Preferred Stock [Member] \| Fairmount [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Gross proceeds (in Dollars)			$ 3,000
Series B Preferred Stock [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Converted shares		137,138
Conversion ratio				83.3332:1
Pre-Merger Oruka [Member] \| Common Stock [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Number of shares issued				39,873,706
Pre-Merger Oruka [Member] \| Series A Preferred Stock [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Issuance costs (in Dollars)			$ 100
Pre-Merger Oruka [Member] \| Series A Preferred Stock [Member] \| Fairmount [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Number of shares issued			20,000,000
Purchase price per share (in Dollars per share)			$ 0.15
PIPE Financing [Member] \| Series A Preferred Stock [Member]
Convertible Preferred Stock and Stockholders’ Equity [Line Items]
Number of shares issued	2,439
Converted shares					2,439