Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (57,887)	$ (58,286)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	6,611	9,326
Depreciation and amortization expense	753	589
Non-cash interest expense	159	0
Loss on disposal of property and equipment	9	0
Deferred rent expense	(97)	(106)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(94)	478
Other assets	21	343
Accounts payable	(3,458)	(653)
Accrued expenses and other current liabilities	(3,137)	1,005
Net cash used in operating activities	(57,120)	(47,304)
Cash flows from investing activities:
Purchases of property and equipment	(181)	(1,344)
Net cash used in investing activities	(181)	(1,344)
Cash flows from financing activities:
Proceeds from exercise of stock options		850
Proceeds from issuance of common stock, net of offering costs	0	(204)
Net cash provided by financing activities	143	15,404
Net decrease in cash, cash equivalents and restricted cash	(57,158)	(33,244)
Cash, cash equivalents and restricted cash at beginning of period	190,059	260,174
Cash, cash equivalents and restricted cash at end of period	132,901	226,930
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued expenses	73	171
Interest paid	628	0
Reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets:
Cash and cash equivalents, end of period	132,409	226,438
Restricted cash	492	492
Cash, cash equivalents and restricted cash at end of period	132,901	226,930
Public Offering [Member]
Cash flows from financing activities:
Proceeds from issuance of common stock, net of offering costs	0	0
At The Market Facility [Member]
Cash flows from financing activities:
Proceeds from issuance of common stock, net of offering costs	0	14,550
ESPP [Member]
Cash flows from financing activities:
Proceeds from issuance of common stock, net of offering costs	$ 143	$ 208