STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (19,720)	$ (44,224)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,374	1,219
Amortization of financing costs	405	0
Stock-based compensation	1,843	7,486
Reduction in the carrying amount of right-of-use assets	2,196	(721)
Gain on lease modification	(133)	0
(Increase) decrease in:
Receivables	1,111	(2,961)
Prepaid expenses and other current assets	316	5,820
Other non-current assets	131	493
Increase (decrease) in:
Accounts payable	(894)	22
Accrued expenses	(368)	(4,742)
Lease liabilities	(2,246)	843
Other non-current liabilities	28	0
Net cash used in operating activities	(15,957)	(36,765)
Cash flows from investing activities:
Purchases of property and equipment	(86)	(2,594)
Net cash used in investing activities	(86)	(2,594)
Cash flows from financing activities:
Proceeds from the exercise of stock options	0	1,036
Net cash provided by financing activities	0	1,036
Net decrease in cash and cash equivalents	(16,043)	(38,323)
Cash and cash equivalents, beginning of period	76,054	115,069
Cash and cash equivalents, end of period	60,011	76,746
Supplementary disclosure of cash flow information:
Cash paid for interest	1,002	0
Amounts included in accrued expenses and accounts payable related to property and equipment	$ 17	$ 258