Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
CURRENT ASSETS:
Cash and cash equivalents	$ 109,014	$ 147,528
Prepaid expenses and other current assets	2,956	2,369
Total current assets	111,970	149,897
Property and equipment, net	63	113
Operating lease right-of-use asset	354	589
Other assets	657	729
TOTAL ASSETS	113,044	151,328
CURRENT LIABILITIES:
Accrued and other liabilities	5,727	7,170
Accounts payable	1,540	1,019
Deferred revenue	200
Warrant liabilities		45,935
Securities issuance obligation		10,485
Total current liabilities	7,467	64,609
Operating lease liability	217	374
TOTAL LIABILITIES	7,684	64,983
Commitments and Contingencies (Note 8)
STOCKHOLDERS’ EQUITY:
Preferred stock, $0.001 par value; 10,000,000 shares authorized as of September 30, 2020 and December 31, 2019; nil shares issued and outstanding as of September 30, 2020 and 103,000 shares of Series A convertible voting preferred stock issued and outstanding as of December 31, 2019		1
Common stock, $0.001 par value; 500,000,000 shares authorized as of September 30, 2020 and December 31, 2019; 10,495,732 and 1,867,176 shares issued and outstanding as of September 30, 2020 and December 31, 2019	10	74
Additional paid-in capital	933,916	851,957
Accumulated deficit	(828,566)	(765,687)
TOTAL STOCKHOLDERS’ EQUITY	105,360	86,345
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 113,044	$ 151,328