Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Activities
Net loss	$ (87,933)	$ (56,241)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	3,405	3,627
Depreciation and amortization	290	138
Changes in operating assets and liabilities:
Accounts receivable	1,495	11,687
Prepaid and other assets	3,880	(3,043)
Accounts payable	500	1,652
Accrued compensation and other accrued liabilities	(3,680)	82
Operating lease liability and right-of-use asset	41	67
Deferred revenue	(1,753)	(13,017)
Net cash flows used in operating activities	(83,755)	(55,048)
Investing Activities
Proceeds from maturities of short-term investments	49,028	107,565
Purchase of short-term and long-term investments		(97,635)
Purchases of property and equipment	(839)	(267)
Net cash flows provided by investing activities	48,189	9,663
Financing Activities
Issuance of common stock for public offering, net of issuance costs	49,250	59,941
Issuance of common stock from ESPP purchase and stock option exercises	303	435
Net cash flows provided by financing activities	49,553	60,376
Net increase in cash and cash equivalents	13,987	14,991
Cash and cash equivalents at beginning of the period	30,360	15,369
Cash and cash equivalents at end of the period	44,347	30,360
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Right-of-use assets obtained in exchange for operating lease liabilities	1,850	$ 476
Remeasurement of right-of-use asset due to operating lease modification	$ 624