Unaudited Consolidated Statement of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (18,978)	$ (24,642)
Adjustment to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	1,693	705
Stock-based compensation expense	1,057	265
Reduction in the operating right of use assets	1,360	1,329
Amortization of debt discount	0	1,283
Change in fair value of derivative liability	0	84
Accretion on marketable securities	0	(163)
Write-off of property and equipment	67	0
Non-cash interest expense	236	41
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,572)	(1,623)
Accounts payable	(1,826)	2,823
Accrued expenses	(2,933)	(4,445)
Deferred revenue	(224)	(323)
Operating lease liabilities	(1,355)	(868)
Other long term liabilities	50	0
Net cash used in operating activities	(22,425)	(25,534)
Cash flows from investing activities:
Purchase of marketable securities	0	(34,460)
Proceeds from the sale of marketable securities	0	31,000
Purchases of property and equipment	(17)	(135)
Net cash used in investing activities	(17)	(3,595)
Cash flows from financing activities:
Cash, cash equivalents and restricted cash acquired in connection with the reverse recapitalization	0	37,903
Payment of reverse recapitalization finance costs	0	(1,742)
Proceeds from the issuance of common stock in pre-closing financing	0	30,640
Payment of principal related to finance lease liabilities	(1,319)	(106)
Proceeds from failed sale-leaseback arrangement	686	1,092
Payment of finance liability from failed sale-leaseback arrangement	(303)	(45)
Proceeds from the exercise of stock options	2	0
Sale of common stock under Open Market Sales Agreement, net of issuance costs	2,286	0
Net cash provided by financing activities	1,352	67,742
Net (decrease) increase in cash, cash equivalents and restricted cash	(21,090)	38,613
Cash, cash equivalents and restricted cash at beginning of the period	77,605	24,194
Cash, cash equivalents and restricted cash at end of the period	56,515	62,807
Supplemental disclosures of cash flow information:
Cash paid for interest	50	45
Supplemental disclosure of non-cash financing and investing activities:
Conversion of convertible preferred stock and non-controlling interests upon Merger	0	122,204
Conversion of convertible promissory note, accrued interest and derivative liability upon Merger	0	42,447
Reverse recapitalization costs in accrued expenses	0	4,071
Unrealized gain on marketable securities	0	177
Right-of-use assets obtained in exchange for new operating lease liabilities	4,337	0
Right-of-use assets obtained in exchange for new financing lease liabilities	2,470	0
Property and equipment in accounts payable	$ 59	$ 49