Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (6,049,000)	$ (9,830,000)	$ (11,927,000)	$ (16,111,000)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation			769,000	3,176,000
Impairment charge on investment in equity securities	0	2,990,000	0	2,990,000
Depreciation			9,000	6,000
Loss on disposal of assets			4,000	0
Changes in operating assets and liabilities:
Prepaid materials			392,000	785,000
Prepaid expenses and other current assets			1,175,000	(91,000)
Other assets			(111,000)	0
Accounts payable			250,000	(1,943,000)
Accrued expenses			934,000	(256,000)
Payroll liabilities			(715,000)	(70,000)
Other current liabilities			(9,000)	27,000
Net cash used in operating activities			(9,229,000)	(11,487,000)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment			(9,000)	(13,000)
Net cash used in investing activities			(9,000)	(13,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from exercise of warrants			304,000	0
Net cash used in financing activities			304,000	0
NET DECREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH			(8,934,000)	(11,500,000)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING BALANCE			88,570,000	111,000,000
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, ENDING BALANCE	79,636,000	99,500,000	79,636,000	99,500,000
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH
Cash and cash equivalents	79,526,000	99,390,000	79,526,000	99,390,000
Restricted cash	110,000	110,000	110,000	110,000
Total cash, cash equivalents and restricted cash	$ 79,636,000	$ 99,500,000	79,636,000	99,500,000
NON CASH INVESTING AND FINANCING ACTIVITIES
Unsettled trades for repurchase of common stock			0	152,000
Common stock issued upon cashless exercise of stock options			$ 228,000	$ 0