CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 141,219	$ 61,653
Available-for-sale securities	0	50,097
Prepaid expenses and other current assets	4,266	3,305
Total Current Assets	145,485	115,055
Property and equipment, net	724	531
Security deposits	343	343
Total Assets	146,552	115,929
Current Liabilities:
Accounts payable	19,028	13,263
Accrued expenses	3,109	4,328
Interest payable on Senior Convertible Debentures	990	1,988
Total Current Liabilities	23,127	19,579
Senior Convertible Notes, net	75,818	151,241
Derivative financial instruments, at estimated fair value-warrants	85	322
Total Liabilities	99,030	171,142
Commitments and contingencies
Stockholders’ Equity/(Deficit):
Preferred stock, Authorized 20,000,000 shares and none outstanding, at June 30, 2016 and December 31, 2015	0	0
Common stock, par value of $.0001, 350,000,000 shares authorized at June 30, 2016 and December 31, 2015. Issued and outstanding 179,776,089 shares and 113,694,606 shares at June 30, 2016 and December 31, 2015, respectively.	18	11
Additional paid-in capital	530,386	329,161
Accumulated Deficit	(482,882)	(384,385)
Total Stockholders’ Equity/(Deficit)	47,522	(55,213)
Total Liabilities and Stockholders’ Equity/(Deficit)	$ 146,552	$ 115,929