BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 31,728	$ 70,946
Receivables	1,021	19
Prepaid expenses and other current assets	14,412	19,818
Total current assets	47,161	90,783
Property and equipment, net	1,344	1,211
Deposits	128	128
Other non-current assets	18,168	13,484
Total assets	66,801	105,606
Current liabilities:
Accounts payable	1,269	4,417
Accrued expenses	9,377	9,909
Contract liability - current portion	49,513	6,389
Deferred rent - current portion	24	141
Total current liabilities	60,183	20,856
Contract liability, net of current portion		35,139
Deferred rent, net of current portion	6	1
Derivative liabilities	2,597	2,424
Total liabilities	62,786	58,420
Commitments and contingencies (Note 6)
Preferred stock, $0.001 par value, 30,000,000 shares authorized
Stockholders' deficit:
Common stock, $0.001 par value; 250,000,000 shares authorized; 142,379,770 and 142,658,037 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively	142	143
Additional paid-in capital	604,653	615,493
Accumulated deficit	(761,209)	(712,442)
Total stockholders' deficit	(156,414)	(96,806)
Total liabilities and stockholders' deficit	66,801	105,606
Series 1 Preferred Stock
Current liabilities:
Series 1 preferred stock, $1,200 stated value; 250,000 designated; 130,849 and 119,644 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively; liquidation value of $157.0 million and $143.6 million at September 30, 2018 and December 31, 2017, respectively	$ 160,429	$ 143,992