Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (131,668)	$ (126,612)	$ (136,639)
Adjustments to reconcile net loss to net cash used in operating activities:
Loss on lease termination	62,685
Stock-based compensation expense	14,609	24,341	24,452
Depreciation and amortization expense	4,931	5,263	5,130
Amortization (accretion) of premium (discount) on marketable securities, net	(7,853)	(9,340)	(2,289)
Other	(97)	27	41
Loss on impairment of property and equipment	259	39	5,811
Changes in operating assets and liabilities:
Collaboration receivable	(1,224)
Tenant receivable		(3,565)	(395)
Prepaid expenses and other current assets	(1,565)	3,156	(3,489)
Operating lease right-of-use assets	3,710	(10,644)	5,935
Other noncurrent assets	(273)	1,433	(1,295)
Accounts payable	(386)	1,087	(1,386)
Accrued expenses and other current liabilities	(7,958)	4,287	795
Deferred revenue	(15,118)	41,596
Operating lease liability	(8,615)	16,187	881
Net cash used in operating activities	(88,563)	(52,745)	(102,448)
Cash flows from investing activities:
Purchases of property and equipment	(2,401)	(7,397)	(8,801)
Proceeds from sale of property and equipment	196
Purchases of marketable securities	(135,266)	(405,301)	(323,714)
Maturities of marketable securities	232,000	403,000	140,000
Net cash provided by (used in) investing activities	94,529	(9,698)	(192,515)
Cash flows from financing activities:
Payment of share issuance costs		(164)	(50)
Proceeds from exercise of stock options and ESPP, net	436	546	1,260
Tax withholding payments related to net share settlements of restricted stock units	(186)	(565)	(581)
Net cash provided by financing activities	250	35,817	12,989
Net increase (decrease) in cash, cash equivalents and restricted cash	6,216	(26,626)	(281,974)
Cash, cash equivalents and restricted cash at beginning of period	72,237	98,863	380,837
Cash, cash equivalents and restricted cash at end of period	78,453	72,237	98,863
Supplemental disclosure of noncash investing and financing information:
Purchases of property and equipment included in accounts payable and accrued expenses	178	1,461	24
Unrealized gains (losses) on marketable securities	$ (115)	356	$ (83)
ModernaTX, Inc
Cash flows from financing activities:
Proceeds from issuance/sale of common stock		$ 36,000