Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (62,680)	$ (55,278)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	5,887	5,447
Depreciation expense	278	1,067
Loss on impairment of long-lived assets	1,592	1,316
Net amortization of premium on short-term investments	(3,496)	(492)
Changes in assets and liabilities:
Prepaid expenses and other current assets	867	(764)
Operating lease right-of-use assets	(5,137)	(868)
Other assets	210	(574)
Accounts payable	450	(2,411)
Accrued expenses and other current liabilities	1,491	4,772
Operating lease liabilities	(1,208)	763
Deferred revenue	(1,558)	3,637
Net cash used in operating activities	(63,304)	(43,385)
Cash flows from investing activities:
Purchases of property and equipment	(1,047)	(164)
Proceeds from maturities of investments	110,886
Purchase of investments	(122,423)	(64,842)
Net cash used in investing activities	(12,584)	(65,006)
Cash flows from financing activities:
Proceeds from sale of common stock, warrants and pre-funded warrants	69,242	100,495
Payment of issuance costs	(3,654)	(4,246)
Proceeds from exercise of stock options	103	8
Net cash provided by financing activities	65,691	96,257
Net decrease in cash, cash equivalents and restricted cash	(10,197)	(12,134)
Cash and cash equivalents and restricted cash, beginning of period	33,942	46,076
Cash and cash equivalents and restricted cash, end of period	23,745	33,942
Supplemental disclosure of non-cash financing and investing activities:
Property and equipment purchases included in accounts payable and accrued expenses	623
Prepaid expenses for right-of-use asset included in operating lease liabilities	2,786	1,960
Modification of lease agreement	4,931	$ 1,928
Right-of-use asset in exchange for lease liability	$ 18,156