Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (111,566)	$ (166,014)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	1,371	1,172
Research and development license expense	3,500	1,250
Stock-based compensation	7,905	18,043
Change in fair value of warrant liability	34,718
Issuance costs for pre-funded warrant liability	2,567
Non-cash loss on debt extinguishment	1,366
Non-cash change in fair value of term loan	1,278
Debt issuance costs expensed under the fair value option	867
Impairment of long-lived assets	1,065	36,420
Non-cash lease expense	1,182	1,315
Other	741	906
Changes in operating assets and liabilities:
Prepaid expenses and other assets	6,011	2,088
Accounts payable	(2,295)	(7,804)
Accrued expenses and other liabilities	(6,277)	(9,323)
Deferred revenue	(15,451)	33,557
Net cash used in operating activities	(73,018)	(88,390)
Cash flows from investing activities
Purchase of research and development license	(3,500)	(4,250)
Purchase of property, plant and equipment	(3,869)	(20,619)
Other	17	(61)
Net cash used in investing activities	(7,352)	(24,930)
Cash flows from financing activities
Proceeds from Trinity term loan, net	39,550
Debt issuance costs for term loan	(399)
Repayment of SVB term loan	(43,000)
Proceeds from issuance of common stock and pre-funded warrants from private placement, net of placement agent commissions and other offering costs	140,290
Payment of offering costs	(387)	(358)
Proceeds from common stock issuances under ESPP	68	253
Other	(229)	(1,042)
Net cash provided by financing activities	136,393	52,097
Net increase (decrease) in cash, cash equivalents and restricted cash	56,023	(61,223)
Cash, cash equivalents and restricted cash at the beginning of the period	90,517	151,740
Cash, cash equivalents and restricted cash at the end of the period	146,540	90,517
Cash and cash equivalents	143,940	87,880
Restricted cash	2,600	2,637
Supplemental disclosure of cash flow information:
Cash paid for interest	4,952	2,775
Supplemental disclosure of noncash investing and financing activities:
Reclassification of warrants to additional paid-in capital	74,342
Allocation of proceeds to Success Fee liability	770
Recognition of asset retirement obligation	449
Property, plant and equipment in accounts payable and accrued expenses		4,002
Right-of-use assets obtained in exchange for lease liabilities		23,432
Offering costs not yet paid	18	387
Issuance of warrants in connection with private placement	252
Public Offering
Cash flows from financing activities
Net proceeds from issuance of common stock		27,717
Offering to Astellas
Cash flows from financing activities
Net proceeds from issuance of common stock		13,887
At-the-Market Offering
Cash flows from financing activities
Net proceeds from issuance of common stock		$ 11,640
Private Placement
Cash flows from financing activities
Net proceeds from issuance of common stock	$ 500