Stock-Based Compensation (Tables)

6 Months Ended

9 Months Ended

Dec. 31, 2024

Sep. 30, 2025

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Schedule of Stock Option Activity

The following table summarizes the stock option activity for the period from June 18, 2024 (inception) to December 31, 2024:

	Number of Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in thousands)
Balance as of June 18, 2024 (inception)		—	$	—		—	$	—
Granted		2,392,751		1.81
Exercised		—		—
Forfeited		—		—
Balance as of December 31, 2024		2,392,751	$	1.81		9.8	$	10,993
Vested and expected to vest, December 31, 2024		2,392,751	$	1.81		9.8	$	10,993
Exercisable, December 31, 2024		1,724	$	0.49		9.7	$	10

The following table summarizes the stock option activity for the nine months ended September 30, 2025:

	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in thousands)
Balance as of December 31, 2024		2,392,751		$	1.81		9.8	$	10,993
Granted		7,818,195			6.97
Exercised		—			—
Forfeited		(510,051	)		4.77
Outstanding at September 30, 2025		9,700,895		$	5.81		9.3	$	29,305
Options vested and exercisable as of September 30, 2025		458,489		$	3.67		8.3	$	2,275

Schedule Of Restricted Stock Awards Activity

The following table summarizes the RSA activity for the period from June 18, 2024 (inception) to December 31, 2024:

	Number of RSAs		Weighted Average Grant Date Fair Value
Unvested balance as of June 18, 2024 (inception)		517,293	$	—
Granted		—		—
Unvested balance as of December 31, 2024		517,293	$	—

The following table summarizes the RSA activity for the nine months ended September 30, 2025:

	Number of RSAs			Weighted Average Grant Date Fair Value
Unvested balance as of December 31, 2024		517,293		$	—
Granted		—			—
Vested		(145,489	)	$	—
Forfeited		—			—
Unvested balance as of September 30, 2025		371,804		$	—

Schedule of 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 June 18, 2024 (Inception) to December 31, 2024
Research and development	$	1,161
General and administrative		95
	$	1,256

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 June 18, 2024 (Inception) to December 31, 2024
Parade warrant obligation	$	1,077
Stock options		179
Restricted stock awards		—
	$	1,256

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

	Three Months Ended September 30, 2025		Nine Months Ended September 30, 2025
Research and development	$	2,452	$	6,674
General and administrative		1,843		3,939
Total	$	4,295	$	10,613

The following table summarizes the stock-based compensation based on type of award for the three and nine months ended September 30, 2025:

	Three Months Ended September 30, 2025		Nine Months Ended September 30, 2025
Parade warrant obligation	$	1,383	$	3,869
Stock options		2,912		6,744
Total	$	4,295	$	10,613

Stock Option Valuation

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Schedule of Assumptions Used in Calculating the Fair Value

The following table summarizes the weighted-average assumptions used in calculating the fair value of the awards for the period June 18, 2024 (inception) to December 31, 2024:

	Period from June 18, 2024 (Inception) to December 31, 2024
Expected volatility		95.4	%
Expected term (in years)		6.1
Risk-free interest rate		4.0	%
Expected dividend yield		—	%

The following table summarizes the weighted-average assumptions used in calculating the fair value of the awards during the nine months ended September 30, 2025:

	Nine Months Ended September 30, 2025
Expected volatility		95.62	%
Expected term (in years)		6.07
Risk-free interest rate		4.35	%
Expected dividend yield		—	%

Parade Warrant Obligation

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Schedule of Assumptions Used in Calculating the Fair Value

The following table summarizes the assumptions used in calculating the fair value of the warrant obligation as of December 31, 2024:

	As of December 31, 2024
Expected volatility		93.3	%
Expected term (in years)		10
Risk-free interest rate		4.6	%
Expected dividend yield		—	%

The following table summarizes the assumptions used in calculating the fair value of the warrant obligation for the three and nine months ended September 30, 2025:

	Nine Months Ended September 30, 2025
Expected volatility		97.8	%
Expected term (in years)		10.0
Risk-free interest rate		4.2	%
Expected dividend yield		—	%