Consolidated Statement of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (86,879)	$ (61,226)
Adjustment to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization expense	2,837	1,893
Loss on disposal of property and equipment	159	0
Stock-based compensation expense	2,316	275
Reduction in the operating right of use assets	5,428	4,197
Amortization of debt discount	1,283	2,537
Change in fair value of derivative liability	84	1,919
Accretion on marketable securities	(709)	0
Realized gain on marketable securities	(399)	0
Non-cash interest expense	139	93
Changes in operating assets and liabilities:
Prepaid expenses and other assets	1,046	(1,361)
Accounts payable	2,191	(473)
Accrued expenses	(2,899)	4,230
Deferred revenue	(1,046)	47,459
Operating lease liabilities	(4,941)	(4,659)
Other long term liabilities	213	0
Net cash used in operating activities	(81,177)	(5,116)
Cash flows from investing activities:
Purchase of marketable securities	(34,460)	(90,900)
Proceeds from the sale of marketable securities	108,000	63,000
Purchases of property and equipment	(1,132)	(4,660)
Net cash provided by (used in) investing activities	72,408	(32,560)
Cash flows from financing activities:
Cash, cash equivalents and restricted cash acquired in connection with the reverse recapitalization	37,903	0
Payment of reverse recapitalization finance costs	(5,814)	0
Proceeds from the issuance of common stock in pre-closing financing	30,640	0
Payment of principal related to finance lease liabilities	(1,301)	(865)
Proceeds from failed sale-leaseback arrangement	1,183	1,626
Payment of finance liability from failed sale-leaseback arrangements	(1,069)	(98)
Payment of deferred financing costs	(146)	(2,450)
Proceeds from issuance of convertible promissory note	0	35,000
Proceeds from the exercise of stock options	187	106
Sale of common stock under Open Market Sales Agreement, net of issuance costs	597	0
Net cash provided by financing activities	62,180	33,319
Net increase (decrease) in cash and cash equivalents	53,411	(4,357)
Cash and cash equivalents at beginning of the year	24,194	28,551
Cash and cash equivalents at end of the year	77,605	24,194
Supplemental disclosures of cash flow information:
Cash paid for interest	352	98
Supplemental disclosure of non-cash financing and investing activities:
Conversion of convertible preferred stock and non-controlling interests upon Merger	122,204	0
Conversion of convertible promissory note, accrued interest and derivative liability upon Merger	42,447	0
Unrealized gain (loss) on marketable securities	41	(41)
Deferred financing costs in accrued expenses	0	1,661
Right-of-use assets obtained in exchange for new operating lease liabilities	2,779	6,440
Right-of-use assets obtained in exchange for new financing lease liabilities	0	2,898
Allocation of debt proceeds to derivative liability	$ 0	$ 3,820