Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows used in operating activities:
Net loss	$ (34,780)	$ (31,620)
Adjustments to reconcile net loss to cash used in operating activities:
Stock-based compensation expense	6,251	8,938
Depreciation and amortization expense	545	305
Reduction in carrying amount of right-of-use asset	1,517	1,184
(Amortization) accretion of (premium) discount on marketable securities	(646)	664
Amortization of debt discount − related party	176	176
Other	32	0
Changes in operating assets and liabilities:
Accounts receivable	945	3,944
Prepaid expenses and other current and long-term assets	498	309
Accounts payable	(138)	(1,152)
Accrued expenses and other current liabilities	(3,670)	(3,766)
Operating lease liability	(1,124)	304
Deferred revenue	(2,731)	(5,882)
Net cash used in operating activities	(33,125)	(26,596)
Cash flows provided by (used in) investing activities:
Proceeds from maturities of marketable securities	65,557	72,387
Purchases of marketable securities	(11,437)	(76,219)
Purchases of property and equipment	(589)	(172)
Net cash provided by (used in) investing activities	53,531	(4,004)
Cash flows (used in) provided by financing activities:
Payment of long-term debt − related party	(750)	0
Payments for repurchase of common stock for tax withholding	(94)	0
Proceeds from exercise of stock options	56	260
Other	104	220
Net cash (used in) provided by financing activities	(684)	480
Net change in cash, cash equivalents and restricted cash	19,722	(30,120)
Cash, cash equivalents and restricted cash at beginning of period	33,033	79,403
Cash, cash equivalents and restricted cash at end of period	52,755	49,283
Reconciliation of cash, cash equivalents and restricted cash:
Cash, cash equivalents and restricted cash at end of period	52,755	49,283
Less: restricted cash	(3,279)	(3,279)
Cash and cash equivalents at end of the period	49,476	46,004
Supplemental disclosures of cash flow information:
Cash paid for interest − related party	430	473
Cash paid for leases	2,120	908
Supplemental disclosures of non-cash investing and financing activities:
Capital expenditures in accounts payable and accrued expenses	196	52
Operating lease liabilities arising from obtaining right-of-use assets	$ 0	$ 44,067