Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating activities
Net loss	$ (26,574)	$ (177,550)
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	2,326	1,380
Expense (gain) on warrants inherited in acquisition of Quellis	1,542	(700)
Other non-cash items	79	10
Changes in assets and liabilities:
Prepaid expenses and other assets	224	999
Right-of-use asset- operating lease	(31)	(85)
Accounts payable	(562)	(2,900)
Accrued expenses	376	(1,882)
Net cash used in operating activities	(22,620)	(16,116)
Investing activities
Purchases of short-term investments	(164,889)
Sales and maturities of short-term investments	130,992	20,000
Cash acquired in acquisition of Quellis		6,466
Purchases of property and equipment	(2)	(21)
Net cash (used in) provided by investing activities	(33,899)	26,445
Financing activities
Proceeds from private offering of public equity, net of issuance costs		104,261
Net cash provided by financing activities		104,261
Net (decrease) increase in cash, cash equivalents and restricted cash	(56,519)	114,590
Cash, cash equivalents and restricted cash, beginning of period	86,629	25,051
Cash, cash equivalents and restricted cash, end of period	$ 30,110	139,641
Supplemental disclosure of non-cash transactions:
Conversion of Series X Preferred Stock into common stock		165,549
Non-cash dividend on convertible preferred stock		24,437
Reclassification of warrant liability to additional paid-in capital		$ 3,468