Fair value measurements

6 Months Ended

Jun. 30, 2024

Fair Value Disclosures [Abstract]

Fair value measurements

Fair value measurements

The following table sets forth the Company’s assets and liabilities that are measured at fair value on a recurring basis as of June 30, 2024 and December 31, 2023 (in thousands):

	Total		Quoted prices in active markets  (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
June 30, 2024
Assets:
Cash and cash equivalents	$	111,864	$	111,864	$	—	$	—
Marketable securities:
U.S. government agency securities and treasuries	63,331		—		63,331		—
Commercial paper	26,678		—		26,678		—
Restricted cash and cash equivalents	433		433		—		—
Restricted investments	34,168		—		34,168		—
Total assets	$	236,474	$	112,297	$	124,177	$	—
December 31, 2023
Assets:
Cash and cash equivalents	$	74,958	$	74,958	$	—	$	—
Marketable securities:
U.S. government agency securities and treasuries	101,625		—		101,625		—
Commercial paper	45,222		—		45,222		—
Restricted cash and cash equivalents	1,725		1,725		—
Restricted investments	32,774		—		32,774		—
Total assets	$	256,304	$	76,683	$	179,621	$	—
Liabilities:
Contingent consideration	$	2,415	$	—	$	—	$	2,415
Total liabilities	$	2,415	$	—	$	—	$	2,415

Contingent consideration

In connection with bluebird bio's prior acquisition of Precision Genome Engineering, Inc. (“Pregenen”) in 2014, the Company may be required to pay future consideration that is contingent upon the achievement of certain commercial milestone events. Contingent consideration is measured at fair value and is based on significant unobservable inputs, which represents a Level 3 measurement within the fair value hierarchy. The valuation of contingent consideration uses assumptions the Company believes would be made by a market participant. The Company assesses these estimates on an on-going basis as additional data impacting the assumptions is obtained. Future changes in the fair value of contingent consideration related to updated assumptions and estimates are recognized within the condensed consolidated statements of operations and comprehensive income (loss). In the absence of new information related to the probability of milestone achievement, changes in fair value will reflect changing discount rates and the passage of time. As of June 30, 2024, the Company determined the probability of milestone achievement to be zero and as a result reduced the fair value of contingent consideration included in other non-current liabilities on the condensed consolidated balance sheets to zero.

The table below provides a roll-forward of fair value of the Company’s contingent consideration obligations that include Level 3 inputs (in thousands):

	For the six months ended June 30, 2024
Beginning balance	$	2,415
Additions	—
Changes in fair value	(2,415)
Payments	—
Ending balance	$	—

Please refer to Note 9, Commitments and contingencies, for further information.