Condensed Consolidated Statements of Cash Flows (Unaudited) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)
Cash flows from operating activities:
Net loss	$ (77,424)	$ (63,834)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	7,598	6,524
Accretion of final payment fee on term loan	365
Amortization of debt issuance costs	227	392
Amortization of premium on available-for-sale securities	(183)	704
Non-cash operating lease expense	135
Depreciation	50	58
Changes in operating assets and liabilities:
Prepaid and other current assets	4,756	(4,119)
Other assets	72	4
Accounts payable	7,308	10,459
Accrued expenses	3,243	1,271
Operating lease liability	(141)
Net cash used in operating activities	(53,994)	(48,541)
Cash flows from investing activities:
Proceeds from maturities of available-for-sale securities	87,260	107,627
Purchases of available-for-sale securities	(110,137)	(119,518)
Purchases of property and equipment	(5)	(36)
Net cash used in investing activities	(22,882)	(11,927)
Cash flows from financing activities:
Proceeds from issuance of common stock and warrants in public offering, net of issuance costs	88,239
Proceeds from issuance of common stock in at-the-market public offering, net of issuance costs	8,370
Proceeds from issuance of common stock upon exercise of stock options	237	446
Proceeds from issuance of common stock upon exercise of warrants	53
Proceeds from issuance of common stock upon ESPP purchases	43	83
Payment of withholding taxes related to restricted stock units	(122)
Proceeds from term loan facility, net of issuance costs		1,451
Net cash provided by financing activities	96,820	1,980
Net change in cash and cash equivalents, and restricted cash	19,944	(58,488)
Cash and cash equivalents, and restricted cash at beginning of period	52,457	98,208
Cash and cash equivalents, and restricted cash at end of period	72,401	39,720
Components of cash and cash equivalents, and restricted cash:
Cash and cash equivalents	72,401	39,695
Restricted cash		25
Total cash and cash equivalents, and restricted cash	72,401	39,720
Supplemental disclosures of cash information:
Cash paid for interest	706	1
Cash paid for operating leases	187
Supplemental disclosures of non-cash information:
Remeasurement of lease liability and right of use asset in connection with lease modification	$ 338
Issuance of common stock warrant in connection with term loan facility		$ 574