Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 49,931	$ 16,369
Prepaid expenses and other current assets	752	1,094
Total current assets	50,683	17,463
Property and equipment, net	51	321
Restricted cash	113	113
Total assets	50,847	17,897
Current liabilities:
Accounts payable	785	773
Accrued expenses	2,999	2,432
Current portion of notes payable, net of discount	831	2,479
Other liability	346	332
Total current liabilities	4,961	6,016
Deferred rent, net of current portion	74	89
Total liabilities	5,035	6,105
Commitments (Note 7)
Stockholders' equity:
Preferred stock, $0.001 par value per share, 5,000,000 shares authorized and no shares issued and outstanding
Common stock, $0.001 par value per share, 150,000,000 shares authorized; 71,038,419 and 23,645,247 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively	71	24
Additional paid-in capital	231,306	183,202
Accumulated deficit	(185,565)	(171,434)
Total stockholders' equity	45,812	11,792
Total liabilities and stockholders' equity	$ 50,847	$ 17,897