Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 11,322	$ 14,430
Grant receivable	294	0
Prepaid expenses and other current assets	923	105
Total current assets	12,539	14,535
Property and equipment, net of accumulated depreciation of $2,397 and $2,311, respectively	1,183	1,222
Right of use asset - operating lease	4,412
Other assets	1	1
Total assets	18,135	15,758
Current liabilities:
Accounts payable	1,534	452
Related party payable	53	100
Accrued expenses	1,727	1,470
Lease liability, current - operating lease	175
Deferred rent, current		150
Total current liabilities	3,489	2,172
Convertible promissory notes, net of debt discount of $18,003 and $18,003, respectively (see Note 5)	0	0
Accrued interest payable	1,935	1,738
Warrant liability	181	152
Derivative liability	1,419	1,474
Lease liability, operating lease	5,108
Deferred rent		665
Total liabilities	12,132	6,201
Stockholders’ equity:
Series A nonredeemable convertible preferred stock; 8,000 shares designated, 8,000 shares issued and outstanding as of March 31, 2019 and December 31, 2018 respectively; aggregate liquidation preference of $8,685 at March 31, 2019 and $8,600 at December 31, 2018.	0	0
Common stock, $0.001 par value; 150,000,000 shares authorized, 9,758,332 shares issued and outstanding at March 31, 2019 and December 31, 2018.	10	10
Additional paid-in capital	198,739	198,627
Accumulated deficit	(192,746)	(189,080)
Total stockholders’ equity	6,003	9,557
Total liabilities and stockholders’ equity	$ 18,135	$ 15,758