CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net loss	$ (79,732)	$ (43,177)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	3,787	2,981
Depreciation and amortization expense	253	265
Non-cash lease expense	775	734
Accretion of debt discount	438	397
Change in fair value of warrant liability	24,421	0
Other	(41)	(294)
Changes in operating assets and liabilities:
Prepaid expenses, other current assets and research and development incentive receivable	479	821
Accounts payable	(2,815)	(605)
Accrued expenses and other long-term liabilities	5,024	651
Lease liabilities	(526)	(476)
Net cash used in operating activities	(47,937)	(38,703)
Payments to Acquire Marketable Securities	(4,876)	0
Cash flows from investing activities:
Acquisition of property and equipment	(17)	(60)
Net cash used in investing activities	(4,893)	(60)
Cash flows from financing activities:
Proceeds from Issuance of Common Stock	8,613	70
Employee taxes paid related to net share settlement of vested restricted stock units	0	(12)
Fees paid to amendment loan and security agreement and issuance costs related to the sale of warrants	(381)	(439)
Repayments of Secured Debt	(1,300)	(795)
Proceeds from sale of shares of common stock, and pre-funded warrants, net of issuance costs	60,282	5,785
Net cash provided by financing activities	67,214	4,609
Effect of exchange rate changes on cash, cash equivalents and restricted cash	44	(271)
Net increase (decrease) in cash, cash equivalents and restricted cash	14,428	(34,425)
Cash, cash equivalents and restricted cash at beginning of period	123,028	83,108
Cash, cash equivalents and restricted cash at end of period	137,456	48,683
Supplemental Cash Flow Elements [Abstract]
Debt Issuance Costs Incurred During Noncash or Partial Noncash Transaction	$ 283	$ 101