CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (37,157)	$ (91,665)
Adjustments to reconcile net loss to net cash from operating activities:
Stock-based compensation expense	10,142	7,080
Gain on disposition	(33,286)
Loss on disposal of property and equipment	42
Non-cash interest expense	470	388
Fair value of common stock earned in connection with license agreement		2,660
Depreciation and amortization expense	5,341	4,363
Accretion of investments		(40)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(1,238)	(117)
Prepaid manufacturing services	63	(101)
Operating right-of-use assets	1,080	1,183
Other non-current assets		48
Accounts payable	96	(378)
Accrued expenses	862	(3,985)
Deferred revenue	(19,048)	7,085
Operating lease liabilities	(1,511)	10,118
Net cash used in operating activities	(74,144)	(63,361)
Cash flows from investing activities:
Purchases of property and equipment	(3,245)	(21,052)
Maturities of investments		73,062
Net cash (used in) provided by investing activities	(3,245)	52,010
Cash flows from financing activities:
Proceeds from long-term debt, net of issuance costs		15,000
Proceeds from exercise of common stock options	3,738	232
Proceeds from public offering of common stock, net of issuance costs	61,674	74,351
Net cash provided by financing activities	65,412	89,583
Net (decrease) increase in cash, cash equivalents and restricted cash	(11,977)	78,232
Cash, cash equivalents and restricted cash, beginning of period	93,085	14,853
Cash, cash equivalents and restricted cash, end of period	81,108	93,085
Supplemental disclosures:
Cash paid for interest	2,242	1,403
Non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued expenses	152	1,122
Deferred offering costs included in accrued expenses	98	165
Accretion of redeemable convertible preferred stock to redemption value		10,784
Operating right-of-use assets obtained in exchange for operating lease liabilities	1,034	23,186
Conversion of convertible preferred stock into common stock		225,568
Reconciliation to amounts within the condensed consolidated balance sheets
Cash and cash equivalents	76,938	88,915
Restricted cash	4,170	4,170
Cash, cash equivalents and restricted cash at end of period	$ 81,108	$ 93,085