CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	[1]
Current assets:
Cash and cash equivalents	$ 112,945	$ 159,180
Short-term marketable securities	40,921	28,103
Related party receivables from collaborative arrangements	35,817	26,228
Prepaid expenses and other current assets	738	814
Total current assets	190,421	214,325
Property and equipment, net	174	221
Capitalized fees paid to a related party, net	187,456	194,368
Other assets	58	18
Total assets	378,109	408,932
Current liabilities:
Accounts payable	137	818
Accrued personnel-related expenses	1,126	1,659
Accrued interest payable	7,823	7,911
Other accrued liabilities	1,392	2,218
Non-recourse notes, due 2029, current	3,266	0
Deferred revenue	885	885
Total current liabilities	14,629	13,491
Convertible subordinated notes, due 2023, net of issuance costs	241,408	250,992
Non-recourse notes, due 2029, net of issuance costs	480,879	482,139
Other long-term liabilities	1,639	1,856
Deferred revenue	2,656	3,099
Commitments and contingencies (Note 9)
Stockholders' deficit:
Preferred stock: $0.01 par value, 230 shares authorized, no shares issued and outstanding
Common stock: $0.01 par value, 200,000 shares authorized, 111,617 and 114,933 shares issued as of June 30, 2016 and December 31, 2015, respectively	1,116	1,149
Treasury stock: 150 shares as of June 30, 2016 and December 31, 2015	(3,263)	(3,263)
Additional paid-in capital	1,312,434	1,351,898
Accumulated other comprehensive income (loss)	6	(2)
Accumulated deficit	(1,673,395)	(1,692,427)
Total stockholders' deficit	(363,102)	(342,645)
Total liabilities and stockholders' deficit	$ 378,109	$ 408,932

[1] Condensed consolidated balance sheet as of December 31, 2015 has been derived from audited consolidated financial statements.