Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 150,431	$ 73,664
Marketable securities	312,277	79,215
Accounts and other receivables	378	95
Prepaid expenses and other current assets	2,172	1,901
Total current assets	465,258	154,875
Marketable securities	12,182
Fixed assets, net	1,880	1,726
Deferred financing costs and other assets	39	54
Restricted cash	152	152
Total assets	479,511	156,807
Current liabilities:
Accounts payable	4,946	6,418
Accrued expenses	12,726	6,446
Deferred revenue	31,592
Current portion of long-term debt	219	195
Total current liabilities	49,483	13,059
Long-term debt	288	279
Total liabilities	$ 49,771	$ 13,338
Commitments and contingencies (Note 14)
Stockholders' Equity:
Common Stock, $.001 par value; 200,000 shares authorized: 136,524 and 103,594 shares issued and outstanding at September 30, 2015 and December 31, 2014, respectively	$ 137	$ 104
Additional paid-in capital	902,257	599,796
Stock subscription receivable		(5,737)
Accumulated deficit	(472,664)	(450,682)
Accumulated other comprehensive income (loss)	10	(12)
Total stockholders' equity	429,740	143,469
Total liabilities and stockholders' equity	$ 479,511	$ 156,807