CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 84,155,000	$ 61,653,000
Available-for-sale securities	0	50,097,000
Prepaid expenses and other current assets	3,361,000	3,305,000
Total Current Assets	87,516,000	115,055,000
Property and equipment, net	534,000	531,000
Security deposits	343,000	343,000
Total Assets	88,393,000	115,929,000
Current Liabilities:
Accounts payable	13,561,000	13,263,000
Accrued expenses	3,229,000	4,328,000
Interest payable on Senior Convertible Debentures	2,474,000	1,988,000
Total Current Liabilities	19,264,000	19,579,000
Senior Convertible Notes, net of deferred financing costs of $3,617 and $7,769 as of March 31, 2016 and December 31, 2015, respectively	75,565,000	151,241,000
Derivative financial instruments, at estimated fair value-warrants	62,000	322,000
Total Liabilities	$ 94,891,000	$ 171,142,000
Commitments and contingencies
Stockholders’ Deficit:
Preferred stock, Authorized 20,000,000 shares and none outstanding, at March 31, 2016 and December 31, 2015	$ 0	$ 0
Common stock, par value of $.0001, 350,000,000 shares authorized at March 31, 2016 and December 31, 2015. Issued and outstanding 149,821,088 shares and 113,694,606 shares at March 31, 2016 and December 31, 2015, respectively.	15,000	11,000
Additional paid-in capital	437,813,000	329,161,000
Accumulated deficit	(444,326,000)	(384,385,000)
Total Stockholders’ Deficit	(6,498,000)	(55,213,000)
Total Liabilities and Stockholders’ Deficit	$ 88,393,000	$ 115,929,000