Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities:
Net loss	$ (62,207)	$ (37,304)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	295	307
Stock-based compensation	6,949	5,021
Non-cash interest expense	342	273
Accretion of discounts on investments, net	342	51
Amortization of right-of-use asset	677	624
Change in fair value of warrant liability		75
Changes in operating assets and liabilities
Prepaid expenses and other current assets	3,534	(4,155)
Accounts payable and accrued liabilities	3,650	(503)
Lease liability	(742)	(600)
Net cash used in operating activities	(47,160)	(36,211)
Investing activities:
Purchases of property and equipment	(8)	(206)
Purchases of short-term investments	(42,673)	(79,874)
Sales and maturities of short-term investments	86,591	47,983
Net cash provided by (used in) investing activities	43,910	(32,097)
Financing activities:
Proceeds from issuance of common stock from initial public offering, net of issuance costs		76,874
Proceeds from issuance of common stock from at-the-market offering program, net of issuance costs	21,661
Proceeds from issuance of long-term debt, net of issuance costs	4,825
Proceeds from exercise of common stock options	1,098	161
Proceeds from issuance of common stock from employee stock purchase plan	184
Repurchase of unvested common stock	(1)	(2)
Net cash provided by financing activities	27,767	77,033
Net increase in cash and cash equivalents	24,517	8,725
Cash and cash equivalents at beginning of year	24,393	15,668
Cash and cash equivalents at end of year	48,910	24,393
Supplemental disclosure of cash flow information:
Cash paid for interest	809	737
Supplemental non-cash investing and financing activities:
Conversion of convertible preferred stock to common stock		122,465
Conversion of convertible preferred stock warrant to common stock warrant		259
Issuance of common stock warrant	374
Vesting of common stock	$ 23	$ 80