Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Cash flows from operating activities:
Net loss	$ (90,122)	$ (49,499)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	8,678	3,807
Amortization of premium on available-for-sale securities	865	268
Amortization of debt issuance costs and accretion of final payment fee	617	230
Depreciation	79	60
Deferred tax assets	(150)	(69)
Changes in operating assets and liabilities:
Prepaid and other current assets	(5,672)	(3,600)
Accounts payable	4,778	1,131
Accrued expenses	4,146	1,428
Net cash used in operating activities	(76,781)	(46,244)
Cash flows from investing activities:
Proceeds from sales and maturities of available-for-sale securities	148,422	12,189
Purchases of available-for-sale securities	(141,200)	(118,895)
Purchases of property and equipment	(63)	(126)
Net cash provided by (used in) investing activities	7,159	(106,832)
Cash flows from financing activities:
Proceeds from term loan facility, net of issuance costs	19,951
Proceeds from issuance of common stock upon public offerings,net of issuance costs	3,289	157,680
Proceeds from issuance of common stock upon stock option exercises	487	271
Payment of debt issuance costs		(161)
Net cash provided by financing activities	23,871	157,924
Net change in cash and cash equivalents, and restricted cash	(45,751)	4,848
Cash and cash equivalents, and restricted cash at beginning of period	98,208	93,360
Cash and cash equivalents, and restricted cash at end of period	52,457	98,208
Components of cash and cash equivalents, and restricted cash:
Cash and cash equivalents	52,432	98,183
Restricted cash	25	25
Total cash and cash equivalents, and restricted cash	52,457	98,208
Supplemental disclosures of cash information:
Cash paid for interest	16
Cash paid for income taxes		142
Supplemental disclosures of noncash information:
Issuance of common stock warrant in connection with term loan facility	574	634
ESPP Purchases
Cash flows from financing activities:
Proceeds from issuance of common stock upon ESPP purchases	$ 144	$ 134