Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 16,111	$ 17,417
Prepaid expenses and other current assets	294	485
Total current assets	16,405	17,902
Property and equipment, net of accumulated depreciation of $2,221 and $1,919, respectively	1,295	1,470
Other assets	1	39
Total assets	17,701	19,411
Current liabilities:
Accounts payable	782	862
Related party payable	63	2,303
Accrued expenses	966	1,260
Total current liabilities	1,811	4,425
Convertible promissory notes, net of debt discount of $18,003 and $18,003, respectively (see Note 4)	0	0
Accrued interest payable	1,542	967
Warrant liability	482	1,073
Derivative liability	2,870	3,136
Deferred rent	812	803
Total liabilities	7,517	10,404
Stockholders’ equity:
Series A nonredeemable convertible preferred stock; 8,000 shares designated, 8,000 shares issued and outstanding as of September 30, 2018 and December 31, 2017 respectively; aggregate liquidation preference of $8,514 at September 30, 2018	0	0
Common stock, $0.001 par value; 150,000,000 shares authorized, 9,314,982 and 5,189,755 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively	9	5
Additional paid-in capital	197,632	187,805
Accumulated deficit	(187,457)	(178,803)
Total stockholders’ equity	10,184	9,007
Total liabilities and stockholders’ equity	$ 17,701	$ 19,411