Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (42,210)	$ (58,505)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	542	690
Amortization of intangible assets	665	665
Stock-based compensation	7,181	5,191
Write-off of excessive and obsolete inventory	0	8,477
Loss on disposal of fixed assets	13	185
Changes in operating assets and liabilities:
Accounts receivable	0	61
Inventory	0	(2,653)
Prepaid expenses and other current assets	(65)	1,164
Other receivables	109	(41)
Right-of-use assets	806	723
Accounts payable	263	(1,304)
Accrued expenses	1,219	(1,794)
Deferred revenue	0	(16)
Lease liabilities	(896)	(774)
Accrued interest on related party note payable	(668)	917
Accrued interest on note payable	0	1
Net cash used in operating activities	(33,041)	(47,013)
Cash flows from investing activities:
Purchases of property and equipment	(121)	(401)
Net cash used in investing activities	(121)	(401)
Cash flows from financing activities:
Proceeds from issuance of common stock under employee stock purchase plan	395	486
Proceeds from exercises of warrants	14,828	26
Proceeds from exercises of stock options	1,171	0
Proceeds from issuance of common stock	0	14,864
Proceeds from issuance of related party note	0	65,000
Issuance cost in relation to related party note extinguishment	(6)	0
Payments made on insurance loan agreement	0	(437)
Net cash provided by financing activities	16,388	79,939
Net (decrease) increase in cash and cash equivalents	(16,774)	32,525
Cash and cash equivalents at beginning of period	61,139	28,614
Cash and cash equivalents at end of period	44,365	61,139
Supplemental disclosure of noncash investing and financing activities:
Principal and accrued interest of related party note settled via issuance of common stock	(65,249)	0
Equipment purchases included in accounts payable and accrued expenses	$ 0	$ (27)