Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 271,953	$ 293,503
Prepaid expenses	8,547	5,994
Other current assets	827	5,206
Total current assets	281,327	304,703
Property and equipment, net	287	245
Intangible assets	102,500	102,500
Goodwill	6,234	6,234
Other assets	1,509	3,931
Total assets	391,857	417,613
Current liabilities:
Accounts payable	2,866	3,356
Accrued expenses	16,024	10,499
Accrued compensation	3,691	6,616
Common stock warrant liabilities	495	512
Total current liabilities	23,076	20,983
Contingent consideration	76,900	76,900
Deferred income taxes	17,425	17,425
Other long-term liabilities	684	784
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.001 par value; 50,000 shares authorized; 34,973 and 34,808 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively	35	35
Additional paid-in capital	875,957	873,526
Accumulated deficit	(602,220)	(572,040)
Total stockholders’ equity	273,772	301,521
Total liabilities and stockholders’ equity	$ 391,857	$ 417,613