CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current Assets:
Cash and cash equivalents	$ 41,916	$ 146,470
Available-for-sale securities	100,085	49,897
Prepaid expenses and other current assets	1,147	3,836
Total Current Assets	143,148	200,203
Property and equipment, net	590	642
Security deposits	219	163
Total Assets	143,957	201,008
Current Liabilities:
Accounts payable	11,612	13,869
Accrued expenses	3,177	1,962
Interest payable on Senior Convertible Debentures	4,969	2,500
Total Current Liabilities	19,758	18,331
Senior Convertible Notes, net of deferred financing costs of $8,276 and $12,336 as of September 30, 2015 and December 31, 2014, respectively	150,735	187,664
Derivative financial instruments, at estimated fair value-warrants	533	172
Total Liabilities	$ 171,026	$ 206,167
Commitments and contingencies
Stockholders' Deficit:
Preferred stock, Authorized 20,000,000 shares and none outstanding, at September 30, 2015 and December 31, 2014
Common stock, par value of $.0001, 350,000,000 shares and 200,000,000 shares authorized at September 30, 2015 and December 31, 2014, respectively. Issued and outstanding 113,673,273 shares and 96,609,764 shares at September 30, 2015 and December 31, 2014, respectively	$ 11	$ 10
Additional paid-in capital	326,858	261,716
Accumulated deficit	(353,938)	(266,885)
Total Stockholders' Deficit	(27,069)	(5,159)
Total Liabilities and Stockholders' Deficit	$ 143,957	$ 201,008