Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating activities
Net loss	$ (38,571)	$ (185,421)
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	3,481	2,390
Expense (gain) on warrants inherited in acquisiton of Quellis	1,542	(315)
Other non-cash items	127	15
Changes in assets and liabilities:
Prepaid expenses and other assets	(468)	(1,092)
Right-of-use asset- operating lease	24	(96)
Accounts payable	(766)	(2,947)
Accrued expenses	1,762	(1,011)
Net cash used in operating activities	(32,869)	(23,865)
Investing activities
Purchases of short-term investments	(217,564)
Sales and maturities of short-term investments	185,675	20,000
Cash acquired in acquisition of Quellis		6,466
Purchases of property and equipment	(60)	(21)
Net cash (used in) provided by investing activities	(31,949)	26,445
Financing activities
Proceeds from private offering of public equity, net of issuance costs		104,261
Proceeds from at-the-market offering, net of issuance costs	24,290
Proceeds from exercise of stock options	34	6
Net cash provided by financing activities	24,324	104,267
Net (decrease) increase in cash, cash equivalents and restricted cash	(40,494)	106,847
Cash, cash equivalents and restricted cash, beginning of period	86,629	25,051
Cash, cash equivalents and restricted cash, end of period	46,135	131,898
Supplemental disclosure of non-cash transactions:
Purchases of property and equipment in accounts payable and accrued liabilities	$ 31
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