Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 15,096	$ 26,634
Marketable securities	8,252	7,501
Accounts receivable	1,027	4,641
Clinical trial retainers	1,702	467
Other prepaid expenses and other current assets	238	1,133
Total current assets	26,315	40,376
Property and equipment, net		23
Clinical trial retainers	940	117
Other assets	30	26
Total assets	27,285	40,542
Current liabilities:
Accounts payable	2,186	1,425
Accrued clinical trial costs and contract research	3,998	1,966
Other accrued liabilities	1,531	2,140
Loans payable, net of discount	2,124	2,053
Deferred revenue	510	814
Settlement liability (Note 15)	4,000	4,000
Total current liabilities	10,349	12,398
Loans payable, net of current portion and discount	11,879	7,418
Deferred revenue	1,697	2,881
Warrant liability (Note 7)	4,593
Other liabilities	690	618
Total liabilities	29,208	23,315
Stockholders' (deficit) equity:
Preferred stock, $.001 par value: 5,000 shares authorized at each of December 31, 2016 and 2015; no shares issued and outstanding at each of December 31, 2016 and 2015
Common stock, $.001 par value: 200,000 shares authorized at each of December 31, 2016 and 2015; 75,863 and 58,182 shares issued and outstanding as of December 31, 2016 and 2015, respectively	76	58
Additional paid-in capital	519,911	512,201
Accumulated other comprehensive income (loss)	6	(3)
Accumulated deficit	(521,916)	(495,029)
Total stockholders’ (deficit) equity	(1,923)	17,227
Total liabilities and stockholders’ (deficit) equity	$ 27,285	$ 40,542