Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2024

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Summary of Fair Value Hierarchy of Assets and Liabilities Measured on Recurring Basis

The following tables present the Company’s fair value hierarchy for its assets and liabilities that are measured at fair value on a recurring basis and indicate the level within the fair value hierarchy of the valuation techniques the Company utilized to determine such fair value (in thousands):

	Fair Value Measurements at June 30, 2024
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	62,394	$	—	$	—	$	62,394
U.S. Treasury bills		—		19,813		—		19,813
Short-term investments:
U.S. Treasury bills, government securities,    and government agency securities		—		225,975		—		225,975
	$	62,394	$	245,788	$	—	$	308,182

	Fair Value Measurements at December 31, 2023
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	23,441	$	—	$	—	$	23,441
U.S. Treasury bills		—		23,832		—		23,832
Short-term investments:
U.S. Treasury bills and government securities		—		77,309		—		77,309
	$	23,441	$	101,141	$	—	$	124,582
Liabilities
Series B preferred stock tranche right liability	$	—	$	—	$	4,200	$	4,200
	$	—	$	—	$	4,200	$	4,200

Schedule of Short-Term Investments

Short-term investments consisted of the following (in thousands):

	June 30, 2024
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Short-term investments:
U.S. Treasury bills, government securities,    and government agency securities	$	226,158	$	—		(183	)		225,975
	$	226,158	$	—		(183	)		225,975

	December 31, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Short-term investments:
U.S. Treasury bills and government securities	$	77,305	$	4	$	—	$	77,309
	$	77,305	$	4	$	—	$	77,309

Summary of Contractual Maturities of Short-term Investments in Available-for-Sale Debt Securities

The contractual maturities of the Company’s short-term investments in available-for-sale debt securities held were as follows (in thousands):

	June 30, 2024		December 31, 2023
Due within one year	$	220,468	$	77,309
Due between one and two years		5,507		—
	$	225,975	$	77,309

Series A Preferred Stock Tranche Right Liability

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Summary of Aggregate Fair Value Determined Using Level 3 Inputs

The following tables provide a roll-forward of the aggregate fair value of the Company’s Series A preferred stock tranche right liability during the six months ended June 30, 2023, for which fair value is determined using Level 3 inputs (in thousands):

	Series A Preferred Stock Tranche Right Liability
Balance as of December 31, 2022	$	10,435
Change in fair value of Series A preferred stock tranche    right liability		1,030
Settlement of Series A preferred stock tranche right    liability upon waiver of milestone		(11,465	)
Balance as of June 30, 2023	$	—

Series B Preferred Stock Tranche Right Liability

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Summary of Aggregate Fair Value Determined Using Level 3 Inputs

The following tables provide a roll-forward of the aggregate fair value of the Company’s Series B preferred stock tranche right liability during the six months ended June 30, 2024, for which fair value is determined using Level 3 inputs (in thousands):

	Series B Preferred Stock Tranche Right Liability
Balance as of December 31, 2023	$	4,200
Change in fair value of Series B preferred stock    tranche right liability		7,390
Settlement of Series B preferred stock tranche right    liability upon waiver of milestone		(11,590	)
Balance as of June 30, 2024	$	—

Summary of Fair Value Measurement Inputs Used in Valuation Model

The significant unobservable inputs used in the valuation model to measure the Series B preferred stock tranche right liability that is categorized within Level 3 of the fair value hierarchy as of December 31, 2023 are as follows:

	Second Tranche Milestone
Probability of meeting Series B milestone		80	%
Milestone achievement date	12/31/2024
Risk-free rate		4.79	%
Expected value of Series B if milestones are not met	$	0.84