Consolidated Balance Sheets - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 32,093,000	$ 38,501,000
Marketable securities	16,175,000	501,000
Funds receivable from New Jersey net operating loss	1,641,000	1,090,000
Accounts receivable		34,000
Prepaid expenses and other current assets	304,000	184,000
Total current assets	50,213,000	40,310,000
Property and equipment, net	4,047,000	6,473,000
Right of use asset, net	149,000	179,000
Patent and trademark rights, net	1,974,000	1,498,000
Marketable securities, long term		15,376,000
Other assets	1,316,000	748,000
Total assets	57,699,000	64,584,000
Current liabilities:
Accounts payable	198,000	383,000
Accrued expenses	438,000	442,000
Current portion of operating lease liability	37,000	47,000
Current portion of financing obligation		230,000
Total current liabilities	673,000	1,102,000
Long-term liabilities:
Operating lease liability	112,000	132,000
Financing obligation arising from sale leaseback transaction (Note 17)		1,876,000
Redeemable warrants	35,000	180,000
Commitments and contingencies (Notes 8, 10, 11, 13, and 17)
Stockholders’ equity:
Series B Convertible Preferred Stock, stated value $1,000 per share, issued and outstanding 715 and 732, respectively	715,000	732,000
Common Stock, par value $0.001 per share, authorized 350,000,000 shares; issued and outstanding 47,994,672 and 42,154,371, respectively	48,000	42,000
Additional paid-in capital	417,217,000	402,541,000
Accumulated other comprehensive loss		(47,000)
Accumulated deficit	(361,101,000)	(341,974,000)
Total stockholders’ equity	56,879,000	61,294,000
Total liabilities and stockholders’ equity	$ 57,699,000	$ 64,584,000