Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net loss	$ (194,912)	$ (37,300)
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	3,362	1,390
Net gain on warrants inherited in acquisiton of Quellis	71
Other non-cash items	21	58
Changes in assets and liabilities:
Prepaid expenses and other assets	85	1,257
Right-of-use asset-operating	(109)	176
Accounts payable	(1,965)	347
Accrued expenses	(1,316)	1,587
Net cash used in operating activities	(30,151)	(32,485)
Investing activities
Purchases of short-term investments	(78,000)	(62,777)
Sales and maturities of short-term investments	59,000	69,110
Cash acquired in acquisition of Quellis	6,466
Purchases of property and equipment	(21)	(33)
Net cash provided by investing activities	(12,555)	6,300
Financing activities
Proceeds from underwritten public offering, net of issuance costs		24,559
Proceeds from private offering of public equity, net of issuance costs	104,261
Proceeds from at-the-market offering, net of issuance costs		16,270
Proceeds from exercise of common stock options	23	31
Net cash provided by financing activities	104,284	40,860
Net increase in cash, cash equivalents and restricted cash	61,578	14,675
Cash, cash equivalents and restricted cash, beginning of period	25,051	10,376
Cash, cash equivalents and restricted cash, end of period	86,629	$ 25,051
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