Condensed Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating Activities
Net loss	$ (83,799)	$ (56,938)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and other expense	45	18
Amortization of premium and discounts on investment securities	540	742
Share-based compensation	11,774	4,371
Changes in operating assets and liabilities:
Income tax receivable	0	1,765
Prepaid expense and other assets	480	990
Accrued interest receivable	57	92
Accrued research and development expenses	2,174	3,128
Accounts payable and accrued expenses	(4,678)	(4,149)
Change in working capital	(14)	73
Net cash used in operating activities	(73,421)	(49,908)
Investing Activities
Purchase of marketable securities	(96,498)	(39,314)
Purchase of property and equipment	(211)	0
Maturities of marketable securities	44,915	72,635
Net cash used in investing activities	(51,794)	33,321
Financing Activities
Proceeds from employee stock plan purchases	4,881	577
Net cash provided by financing activities	4,881	577
Net increase (decrease) in cash and cash equivalents	(120,334)	(16,010)
Cash and cash equivalents
Beginning of period	261,447	66,373
End of period	141,113	50,363
Supplemental disclosure of cash paid
Income tax refunds received	0	1,765
Supplemental disclosures of non-cash information related to investing activities
Operating right-of-use assets obtained in exchange for lease obligations	$ 953	$ 2,086