Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Cash flows from operating activities:
Net loss	$ (212)	$ (22,528)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	0	347
Gain on disposal of property and equipment	(81)	(1,147)
Impairment loss on fixed assets	0	5,011
Impairment loss on ROU assets	0	9,571
Gain on lease termination	0	(3,271)
Impairment of prepaid research and development	0	5,219
Equity-based compensation expense	54	2,719
Change in fair value of warrant liability	(1,094)	(14,958)
Accretion/amortization of investment securities	0	(242)
Reduction in carrying amount of operating lease right of use asset	0	948
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	537	430
Prepaid research and development, net of current portion	0	1,906
Accounts payable and accrued expenses	(1,204)	(2,034)
Operating lease liabilities	0	(12,417)
Other assets	0	4
Net cash used in operating activities	(2,000)	(30,442)
Cash flows from investing activities:
Purchases of marketable securities	0	(1,477)
Proceeds from maturity of marketable securities	0	25,499
Purchases of property and equipment	0	(14)
Proceeds from the sale of property and equipment	167	1,229
Net cash provided by investing activities	167	25,237
Cash flows from financing activities:
Payments on finance lease obligations	0	(4)
Proceeds from employee stock purchases and exercise of stock options	0	153
Net cash provided by financing activities	0	164
Net decrease in cash, cash equivalents and restricted cash	(1,833)	(5,041)
Cash, cash equivalents and restricted cash at beginning of period	18,910	25,057
Cash, cash equivalents and restricted cash at end of period	17,077	20,016
Supplemental disclosure of non-cash investing activities:
Assets acquired under operating lease obligation	0	1,626
Property and equipment sales included in other current assets	0	61
Supplemental disclosure of non-cash financing activities:
Cash paid for income taxes	0	5
Pre-Funded Warrants
Cash flows from financing activities:
Proceeds from exercise of pre-funded warrants	0	2
At-the-market Offering
Cash flows from financing activities:
Proceeds from issuance of common stock in connection with at-the-market offering, net of issuance costs	$ 0	$ 13