Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net loss	$ (51,834)	$ (194,912)
Reconciliation of net loss to net cash used in operating activities:
Non-cash portion of acquired in-process research and development		164,612
Stock-based compensation expense	4,554	3,362
Expense on warrants inherited in acquisition of Quellis	1,542	71
Right-of-use asset- operating lease	(554)	572
Other non-cash items	112	21
Changes in assets and liabilities:
Prepaid expenses and other assets	(1,568)	85
Lease liability - operating lease	574	(681)
Accounts payable	(766)	(1,965)
Accrued expenses	4,407	(1,316)
Net cash used in operating activities	(43,533)	(30,151)
Investing activities
Purchases of short-term investments	(396,064)	(78,000)
Sales and maturities of short-term investments	229,026	59,000
Cash acquired in acquisition of Quellis		6,466
Purchases of property and equipment	(91)	(21)
Net cash used in investing activities	(167,129)	(12,555)
Financing activities
Proceeds from public offering, net of underwritting discounts and issuance costs	107,646	104,261
Proceeds from at-the-market offering, net of issuance costs	36,991
Proceeds from exercise of stock options	84	23
Net cash provided by financing activities	144,721	104,284
Net (decrease) increase in cash, cash equivalents and restricted cash	(65,941)	61,578
Cash, cash equivalents and restricted cash, beginning of period	86,629	25,051
Cash, cash equivalents and restricted cash, end of period	20,688	86,629
Supplemental disclosure of non-cash investing and financing activities:
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	1,268
Supplemental disclosure of non-cash transactions:
Conversion of Series X Preferred Stock into common stock		168,920
Non-cash dividend on convertible preferred stock		24,437
Reclassification of warrant liability to additional paid-in capital		$ 3,468
Public offering issuance costs in accrued expenses	$ 100