Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 23,457	$ 29,785
Marketable securities	10,163	17,960
Accounts receivable	2,779	1,631
Clinical trial retainers	402	589
Other prepaid expenses and other current assets	263	635
Total current assets	37,064	50,600
Property and equipment, net	100
Operating lease right-of-use asset	1,225
Other assets	158
Total assets	38,547	50,600
Current liabilities:
Accounts payable	2,965	1,466
Accrued clinical trial costs and contract research	5,100	5,680
Other accrued liabilities	1,476	2,336
Operating lease liability	438
Loans payable, net of discount	9,876	9,569
Deferred revenue	1,974	1,974
Deferred research and development reimbursements	210	93
Total current liabilities	22,039	21,118
Loans payable, net of current portion and discount	3,610	6,197
Deferred revenue	2,059	2,552
PIPE Warrant liability (Note 7)	2,449	5,097
Operating lease liability, non-current	592
Other liabilities (Note 6)	790	790
Total liabilities	31,539	35,754
Stockholders’ equity:
Preferred stock, $.001 par value: 5,000 shares authorized at March 31, 2020 and December 31, 2019; no shares issued and outstanding at each of March 31, 2020 and December 31, 2019
Common stock, $.001 par value: 50,000 shares authorized at March 31, 2020 and December 31, 2019; 16,081 shares issued and outstanding at each of March 31, 2020 and December 31, 2019	161	161
Additional paid-in capital	600,849	600,306
Accumulated deficit	(594,002)	(585,621)
Total stockholders’ equity	7,008	14,846
Total liabilities and stockholders’ equity	$ 38,547	$ 50,600