Condensed Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 19,024	$ 18,456
Short-term investments	80,984	101,548
Accounts receivable, net	14	107
Prepaid and other current assets	2,398	2,334
Total current assets	102,420	122,445
Restricted cash	1,160	1,158
Property and equipment, net	4,529	4,679
Other long-term assets	82	82
Total assets	108,191	128,364
Current liabilities:
Accounts payable	877	961
Accrued expenses	2,645	3,881
Accrued compensation	1,943	3,307
Current portion of deferred rent	39	42
Total current liabilities	5,504	8,191
Deferred rent, net of current portion	2,951	2,894
Total liabilities	8,455	11,085
Commitments and Contingencies
Stockholders' equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized at June 30, 2018 and December 31, 2017; no shares issued or outstanding at June 30, 2018 and December 31, 2017	0	0
Common stock, $0.001 par value; 200,000,000 shares authorized at June 30, 2018 and December 31, 2017; 30,630,125 and 30,558,726 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively	31	31
Additional paid-in capital	489,578	482,198
Accumulated other comprehensive loss	(46)	(100)
Accumulated deficit	(389,827)	(364,850)
Total stockholders' equity	99,736	117,279
Total liabilities and stockholders' equity	$ 108,191	$ 128,364