Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 23,483	$ 24,427
Accounts receivable	2,571	3,026
Clinical trial retainers	42	126
Other prepaid expenses and other current assets	199	356
Total current assets	26,295	27,935
Other assets	212
Total assets	26,507	27,935
Current liabilities:
Accounts payable	2,109	3,499
Accrued clinical trial costs and contract research	6,352	6,254
Other accrued liabilities	2,132	2,698
Loans payable, net of discount	5,688	3,254
Deferred revenue	1,974	1,658
Deferred research and development reimbursements	336	454
Other liabilities (Note 6)	300	300
Total current liabilities	18,891	18,117
Loans payable, net of current portion and discount	13,511	15,779
Deferred revenue	4,032	3,802
PIPE Warrant liability (Note 7)	7,859	16,674
Other liabilities (Note 6)	790	790
Total liabilities	45,083	55,162
Stockholders’ deficit:
Preferred stock, $.001 par value: 5,000 shares authorized at March 31, 2019 and December 31, 2018; no shares issued and outstanding at each of March 31, 2019 and December 31, 2018
Common stock, $.001 par value: 250,000 shares authorized at March 31, 2019 and December 31, 2018; 139,000 and 126,485 shares issued and outstanding as of March 31, 2019 and December 31, 2018, respectively	139	126
Additional paid-in capital	575,738	567,655
Accumulated other comprehensive income	1	1
Accumulated deficit	(594,454)	(595,009)
Total stockholders’ deficit	(18,576)	(27,227)
Total liabilities and stockholders’ deficit	$ 26,507	$ 27,935