Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2023

Fair Value Disclosures [Abstract]

Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table sets forth the fair value of the Company’s financial assets and liabilities measured 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	$	168,800	$	—	$	—	$	168,800
U.S. Treasury securities	—		249,157		—		249,157
U.S. government agency securities	—		68,953		—		68,953
Corporate debt securities	—		89,563		—		89,563
Total financial assets	$	168,800	$	407,673	$	—	$	576,473
Financial liabilities:
Success payment liabilities	$	—	$	—	$	1,047	$	1,047
Total financial liabilities	$	—	$	—	$	1,047	$	1,047

	December 31, 2022
	Level 1		Level 2		Level 3		Total
Financial assets:
Money market funds	$	67,970	$	—	$	—	$	67,970
U.S. Treasury securities	—		271,799		—		271,799
U.S. government agency securities	—		134,045		—		134,045
Corporate debt securities	—		220,681		—		220,681
Total financial assets	$	67,970	$	626,525	$	—	$	694,495
Financial liabilities:
Success payment liabilities	$	—	$	—	$	4,356	$	4,356
Total financial liabilities	$	—	$	—	$	4,356	$	4,356

Schedule of Estimated Fair Value of Success Payment Liability Assumptions

The following assumptions were incorporated into the calculation of the estimated fair value of the Fred Hutch success payment liability:

	September 30, 2023			December 31, 2022
Fair value of common stock	$	1.47		$	3.47
Risk-free interest rate	4.26% - 5.42%			3.58% - 4.65%
Expected volatility	80.0		%	80.0		%
Expected term (in years)	0.71 - 4.22			0.46 - 4.97

The following assumptions were incorporated into the calculation of the estimated fair value of the Stanford success payment liability:

	September 30, 2023			December 31, 2022
Fair value of common stock	$	1.47		$	3.47
Risk-free interest rate	4.21% - 5.42%			3.58% - 4.65%
Expected volatility	80.0		%	80.0		%
Expected term (in years)	0.71 - 6.00			0.46 - 6.75

Schedule of Changes in the Estimated Fair Value of Level 3 Financial Assets

The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 liabilities (in thousands):

	Success Payment Liabilities
Balance at December 31, 2022	$	4,356
Change in fair value (1)	(3,309)
Balance at September 30, 2023	$	1,047

(1)The change in the fair value associated with the Fred Hutch success payment liabilities of approximately $(2.1) million is recorded in other income (expense), net. The change in the fair value of approximately $(1.2) million associated with the Stanford success payment liabilities is recorded as research and development expenses. (See Note 3, License, Collaboration and Success Payment Agreements).