Fair Value Measurements

6 Months Ended

Jun. 30, 2024

Fair Value Disclosures [Abstract]

Fair Value Measurements

Note 3. Fair value measurements

The following tables summarize the Company’s financial assets measured at fair value on a recurring basis and their respective input levels based on the fair value hierarchy (in thousands):

			Fair value measurements as of June 30, 2024 using
			Quoted prices in		Significant		Significant
			active markets		other		unobservable
	June 30,		for identical		observable		inputs
	2024		assets (level 1)		inputs (level 2)		(level 3)
Assets:
Money market funds(1)	$	169,440	$	169,440	$	—	$	—
US treasury securities(2)		54,219		54,219		—		—
US government agency securities(2)		40,633		—		40,633		—
Corporate debt securities(2)		39,597		—		39,597		—
Commercial paper(2)		101,161		—		101,161		—
US treasury securities(3)		29,619		29,619		—		—
US government agency securities(3)		22,217		—		22,217		—
Total fair value of assets	$	456,886	$	253,278	$	203,608	$	—

(1)Included as cash and cash equivalents on the condensed consolidated balance sheets.

(2)Included as short-term marketable securities on the condensed consolidated balance sheets.

(3)Included as long-term marketable securities on the condensed consolidated balance sheets.

			Fair value measurements as of December 31, 2023 using
			Quoted prices in		Significant		Significant
			active markets		other		unobservable
	December 31,		for identical		observable		inputs
	2023		assets (level 1)		inputs (level 2)		(level 3)
Assets:
Money market funds(1)	$	83,101	$	83,101	$	—	$	—
US treasury securities(2)		93,303		93,303		—		—
US government agency securities(2)		26,824		—		26,824		—
Corporate debt securities(2)		10,734		—		10,734		—
Commercial paper(2)		88,414		—		88,414		—
US treasury securities(3)		9,642		9,642		—		—
Total fair value of assets	$	312,018	$	186,046	$	125,972	$	—

(1)Included as cash and cash equivalents on the condensed consolidated balance sheets.

(2)Included as short-term marketable securities on the condensed consolidated balance sheets.

(3)Included as long-term marketable securities on the condensed consolidated balance sheets.

The carrying amounts of the Company’s financial instruments, including cash, prepaid expenses and other current assets, accounts payable and accrued expenses and other current liabilities, approximate fair value due to their short maturities. As of June 30, 2024 and December 31, 2023, the Company held $1.8 million and $2.0 million in equity investments in Affini-T Therapeutics, Inc. (Affini-T) at cost, less impairment, respectively. An impairment adjustment of $402,000 was made to the value of the Company’s equity investment in Affini-T during the three months ended June 30, 2024. The Company was notified by Affini-T of an extension financing in June 2024 and the terms of such financing. Accordingly, the Company reassessed the value of its equity investment in Affini-T using a market approach. This represents a Level 3 nonrecurring fair value measurement. Calculating the fair value of the equity investment involves unobservable inputs, including the terms and preferences of the extension financing, and significant estimates and assumptions. Changes in the estimates and assumptions used could materially affect the amount of impairment loss recognized in the period the equity investment is considered impaired. This impairment was offset by a new investment obligation of approximately $235,000 recorded as of June 30, 2024. In July 2024, the Company paid approximately $157,000 of the obligation related to the extension financing. No transfers between levels have occurred during the periods presented.

Cash equivalents consist of money market funds, short-term marketable securities consist of US treasury securities, US government agency securities, corporate debt securities and commercial paper, and long-term marketable securities consist of US treasury securities and US government agency securities. The Company obtains pricing information from its investment manager and generally determines the fair value of marketable securities using standard observable inputs, including benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, and bid and/or offers.