CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 27,583	$ 32,349
Short-term investments	30,335	48,548
Prepaid expenses and other current assets	1,835	398
Total current assets	59,753	81,295
Property and equipment, net	1,127	1,417
Restricted cash	162	162
Other assets	797	755
Total assets	61,839	83,629
Current liabilities:
Accounts payable	6,825	4,095
Accrued expenses	4,241	6,896
Total current liabilities	11,066	10,991
Long-term debt	2,293
Other non-current liabilities	248	341
Total liabilities	13,607	11,332
Stockholders' equity
Preferred stock, $0.0001 par value; 5,000 shares authorized, no shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively	0	0
Common stock, $0.0001 par value; 100,000 shares authorized, 36,992 shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively	4	4
Additional paid-in capital	310,014	307,587
Accumulated other comprehensive (loss) income	(5)	29
Accumulated deficit	(261,781)	(235,323)
Total stockholders' equity	48,232	72,297
Total liabilities and stockholders' equity	$ 61,839	$ 83,629