Condensed Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (44,060)	$ (43,363)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	431	395
Stock-based compensation	10,089	9,015
Non-cash lease expense	513	565
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	2,293	749
Accounts payable and accrued expenses	(3,563)	6,789
Lease liability	(598)	(486)
Net cash used in operating activities	(34,895)	(26,336)
Cash flows from investing activities:
Purchase of property and equipment	(618)	(735)
Net cash used in investing activities	(618)	(735)
Cash flows from financing activities:
Principal payments on term loan payable	0	(846)
Proceeds from exercise of common stock options and employee stock purchase plan	158	1,037
Net cash provided by financing activities	158	191
Change in cash, cash equivalents, and restricted cash	(35,355)	(26,880)
Cash, cash equivalents, and restricted cash at beginning of period	254,295	386,919
Cash, cash equivalents, and restricted cash at end of period	218,940	360,039
Supplemental disclosure of cash flow information:
Right-of-use assets and lease liabilities derecognized	$ (303)	$ 0