Fair Value Measurement (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2023

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Financial Assets and Liabilities Measured at Fair Value on Recurring Basis

The following tables set forth the fair value of the Company’s financial assets and liabilities at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands):

	September 30, 2023
	Level 1		Level 2		Level 3		Total
Financial Assets:
Money market funds	$	55,451	$	—	$	—	$	55,451
Commercial paper		—		107,093		—		107,093
Corporate bonds		—		22,828		—		22,828
Total financial assets	$	55,451	$	129,921	$	—	$	185,372
Liabilities:
Parapyre Option Obligation	$	—	$	2,952	$	—	$	2,952
CVR liability		—		—		28,200		28,200
Total liabilities	$	—	$	2,952	$	28,200	$	31,152
	December 31, 2022
	Level 1		Level 2		Level 3		Total
Financial Assets:
Money market funds	$	15,250	$	—	$	—	$	15,250
Commercial paper		—		23,641		—		23,641
U.S. government securities		—		4,230		—		4,230
Corporate bonds		—		3,732		—		3,732
Total financial assets	$	15,250	$	31,603	$	—	$	46,853

The following tables sets forth the fair value of the Company’s financial assets and liabilities at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands):

	December 31, 2022
	Level 1		Level 2		Level 3		Total
Financial Assets
Money market funds	$	15,250	$	—	$	—	$	15,250
Commercial paper		—		23,641		—		23,641
U.S. government securities		—		4,230		—		4,230
Corporate bonds		—		3,732		—		3,732
Total financial assets	$	15,250	$	31,603	$	—	$	46,853

	December 31, 2021
	Level 1		Level 2		Level 3		Total
Financial Assets
Money market funds	$	8,888	$	—	$	—	$	8,888
Commercial paper		—		65,412		—		65,412
Corporate bonds		—		12,574		—		12,574
Total financial assets	$	8,888	$	77,986	$	—	$	86,874

Significant Inputs used to Estimate the Fair Value of Derivative Liabilities

The significant inputs used to estimate the fair value of the CVR liability were as follows:

	September 30, 2023
Estimated cash flow dates	11/28/23 - 06/22/26
Estimated probability of success	27% - 100%
Risk-adjusted discount rates	7.14% - 7.57%

Changes in Derivative Liabilities

The following table presents changes in the forward contract liability for the periods presented (in millions):

	Forward Contract Liability
Beginning balance as of June 22, 2023	$	106.2
Change in fair value		58.1
Ending balance as of June 30, 2023		164.3
Change in fair value		25.4
Issuance of Series A Preferred Stock on July 7, 2023		(189.7	)
Ending balance as of September 30, 2023	$	—

The following table presents changes in the CVR liability for the periods presented (in thousands):

	CVR Liability
Beginning balance as of December 31, 2022	$	—
Fair value at CVR issuance		29,500
Changes in the fair value of the CVR liability since issuance	$	(1,300	)
Ending Balance as of September 30, 2023	$	28,200