Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net loss	$ (24,533)	$ (14,185)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	58	5
Non-cash lease costs	318	58
Stock-based compensation	5,501	1,800
Net amortization of premiums and accretion of discounts on investments	107
Changes in operating assets and liabilities
Prepaid expenses and other current assets	(1,577)	(453)
Other assets	(317)	(583)
Accounts payable	1,553	7,346
Payable and accrued liabilities due to related party	(184)
Accrued expenses and other current liabilities	(1,304)	585
Other non-current liabilities	(296)	292
Net cash used in operating activities	(20,674)	(5,135)
Investing activities
Purchase of investments	(183,332)
Purchase of property and equipment	(589)	(7)
Net cash provided by (used in) investing activities	(183,921)	(7)
Financing activities
Proceeds from exercise of stock options under equity incentive plan	185	778
Principal payments on finance leases	(105)
Net cash provided by financing activities	80	778
Net decrease in cash, cash equivalents and restricted cash	(204,515)	(4,364)
Cash, cash equivalents and restricted cash at beginning of year	363,667	434,219
Cash, cash equivalents and restricted cash at end of year	159,152	429,855
Supplemental disclosure of non-cash investing and financing activities
Purchase of property and equipment in accounts payable and accrued expenses	147
Right-of-use asset acquired under operating leases	3,419
Receivables for cash in-transit on exercise of common stock under equity incentive plans		246
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents	159,086	429,855
Restricted cash (included in other assets)	66
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Total	$ 159,152	$ 429,855