Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 26,356	$ 23,746
Short-term investments	268,201	296,736
Restricted cash	194	194
Prepaid expenses and other current assets	4,132	3,921
Total current assets	298,883	324,597
Property and equipment, net	1,830	270
Other assets	101	108
Total assets	300,814	324,975
Current liabilities:
Accounts payable	3,235	1,445
Accrued compensation	2,135	2,624
Accrued research and development expenses	3,799	5,112
Other accrued liabilities	837	528
Total current liabilities	10,006	9,709
Long-term liabilities	563	166
Total liabilities	10,569	9,875
Commitments and contingencies (Note 6)
Stockholders’ equity:
Common stock—$0.0001 par value, 500,000,000 shares authorized as of June 30, 2016 and December 31, 2015; 28,705,875 and 28,458,807 shares issued and outstanding as of June 30, 2016 and December 31, 2015, respectively	3	3
Additional paid-in capital	423,600	413,725
Accumulated other comprehensive income (loss)	193	(518)
Accumulated deficit	(133,551)	(98,110)
Total stockholders’ equity	290,245	315,100
Total liabilities and stockholders’ equity	$ 300,814	$ 324,975