Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 23,395	$ 27,053
Marketable securities	7,454	7,137
Funds receivable from New Jersey net operating loss	1,763	1,676
Prepaid expenses and other current assets	548	455
Total current assets	33,160	36,321
Property and equipment, net	155	195
Right of use asset, net	792	829
Patent and trademark rights, net	1,898	1,941
Other assets	1,457	1,202
Total assets	37,462	40,488
Current liabilities:
Accounts payable	963	377
Accrued expenses	696	806
Current portion of operating lease liability	178	178
Total current liabilities	1,837	1,361
Long-term liabilities:
Operating lease liability	636	659
Commitments and contingencies (Notes 12 and 13)
Stockholders’ equity:
Series B Convertible Preferred Stock, stated value $1,000 per share, 692 and 696 issued and outstanding, respectively	692	696
Common Stock, par value $0.001 per share, authorized 350,000,000 shares, 48,407,326 and 48,084,287 issued and outstanding, respectively	48	48
Additional paid-in capital	418,456	418,270
Accumulated deficit	(384,207)	(380,546)
Total stockholders’ equity	34,989	38,468
Total liabilities and stockholders’ equity	$ 37,462	$ 40,488