Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (21,038)	$ (15,399)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization expense	276	327
Amortization of operating lease right-of-use assets	2,476	2,474
Stock-based compensation expense	1,947	1,581
Loss on disposal of equipment	41
Changes in operating assets and liabilities:
Accounts receivable	3,000	1,892
Prepaid expenses and other current assets	(881)	(1,603)
Accounts payable	(2,729)	572
Accrued expenses	1,716	(2,645)
Deferred revenue	(2,869)	(5,454)
Operating lease liabilities	(2,373)	(2,329)
Net cash used in operating activities	(20,434)	(20,584)
Cash flows from investing activities:
Purchases of property and equipment	(228)	(247)
Proceeds from disposals of property and equipment	34
Cash flows from investing activities	(194)	(247)
Cash flows from financing activities:
Proceeds from follow-on public offering of common stock, net of commissions and underwriting discounts		56,400
Payment of issuance costs		(1,296)
Proceeds from exercise of stock options	29	299
Net cash provided by financing activities	29	55,403
Net (decrease) increase in cash, cash equivalents and restricted cash	(20,599)	34,572
Cash, cash equivalents and restricted cash at beginning of period	145,818	172,662
Cash, cash equivalents and restricted cash at end of period	$ 125,219	207,234
Supplemental disclosure of non-cash investing and financing activities:
Deferred offering costs included in accrued expenses at end of period		$ 605