Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 33,908	$ 1,470
Marketable securities, short term	1,093	7,308
Funds receivable from sale of New Jersey net operating loss		776
Accounts receivable, net	46	44
Prepaid expenses and other current assets	118	848
Total current assets	35,165	10,446
Property and equipment, net	6,785	7,116
Right of use assets, net	130	152
Patent and trademark rights, net	1,381	1,151
Marketable securities, long term	5,308
Other assets	1,354	1,354
Total assets	50,123	20,219
Current liabilities:
Accounts payable	255	472
Accrued expenses	325	403
Current portion of operating lease liabilities	32	38
Current portion of financing obligation	221	214
Total current liabilities	833	1,127
Long-term liabilities:
Operating lease obligation	98	114
Notes payable, net		3,910
Financing obligation arising from sale leaseback transaction (Note 14)	1,993	2,104
Redeemable warrants	207	57
Commitments and contingencies
Stockholders' equity:
Series B Convertible Preferred Stock, stated value $1,000 per share, 8,000 shares designated, 737 and 778 shares issues and outstanding, respectively	737	778
Common stock, par value $0.001 per share, authorized 350,000,000 shares; issued and outstanding 34,250,615 and 10,386,754, respectively	34	10
Additional paid-in capital	381,427	340,228
Accumulated other comprehensive income (loss)	63
Accumulated deficit	(335,269)	(328,109)
Total stockholders' equity	46,992	12,907
Total liabilities and stockholders' equity	$ 50,123	$ 20,219