Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 60,493	$ 47,968
Short-term investments	139,728	207,714
Restricted cash - short-term	194	194
Prepaid expenses and other current assets	5,802	4,677
Total current assets	206,217	260,553
Property and equipment, net	22,176	3,259
Restricted cash - long-term	1,200	0
Other assets	100	102
Total assets	229,693	263,914
Current liabilities:
Accounts payable	5,539	2,778
Accrued compensation	5,319	3,745
Accrued research and development expenses	3,810	2,408
Other accrued liabilities	1,848	744
Total current liabilities	16,516	9,675
Long-term liabilities	7,221	503
Total liabilities	23,737	10,178
Commitments and contingencies (Note 7)
Stockholders’ equity:
Common stock—$0.0001 par value, 500,000 shares authorized as of September 30, 2017 and December 31, 2016; 30,596 and 28,933 shares issued and outstanding as of September 30, 2017 and December 31, 2016, respectively	3	3
Additional paid-in capital	467,378	431,075
Accumulated other comprehensive loss	(88)	(183)
Accumulated deficit	(261,337)	(177,159)
Total stockholders’ equity	205,956	253,736
Total liabilities and stockholders’ equity	$ 229,693	$ 263,914