Condensed Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating Activities
Net loss	$ (56,938)	$ (33,665)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and other expense	18	77
Amortization of premium and discounts on investment securities	742	0
Share-based compensation	4,371	4,197
Changes in operating assets and liabilities:
Income tax receivable	1,765	0
Prepaid expense and other assets	990	(155)
Accrued interest receivable	92	0
Accrued research and development expenses	3,128	271
Accounts payable and accrued expenses	(4,149)	(995)
Change in working capital	73	0
Net cash used in operating activities	(49,908)	(30,270)
Investing Activities
Purchase of marketable securities	(39,314)	0
Maturities of marketable securities	72,635	0
Net cash provided by investing activities	33,321	0
Financing Activities
Proceeds from employee stock plan purchases	577	186
Net cash provided by financing activities	577	150,306
Net decrease in cash and cash equivalents	(16,010)	120,036
Cash and cash equivalents
Beginning of period	66,373	125,699
End of period	50,363	245,735
Supplemental disclosure of cash paid
Income tax refunds received	1,765	3,327
Underwritten Offering
Financing Activities
Proceeds from issuance of common stock	0	116,883
Private Placement
Financing Activities
Proceeds from issuance of common stock	$ 0	$ 33,237