Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 16,817	$ 68,840
Available-for-sale investments	57,919	14,755
Prepaid expenses and other current assets	1,052	1,006
Total current assets	75,788	84,601
Property and equipment, net	102	83
Other non-current assets	685	114
Total assets	76,575	84,798
Current liabilities:
Accounts payable	502	917
Accrued expenses	2,202	$ 1,421
Other current liabilities	61
Total current liabilities	2,765	$ 2,338
Other non-current liabilities	51
Total liabilities	$ 2,816	$ 2,338
Commitments and contingencies (Note 6)
Stockholders’ equity:
Preferred stock, $0.001 par value per share; 10,000,000 shares authorized, no shares issued and outstanding at June 30, 2015 and December 31, 2014
Common stock, $0.001 par value, 100,000,000 shares authorized at June 30, 2015 and December 31, 2014; 16,458,477 and 16,448,455 shares issued and outstanding at June 30, 2015 and December 31, 2014, respectively	$ 16	$ 16
Additional paid-in capital	193,266	192,324
Accumulated deficit	(119,526)	(109,874)
Accumulated other comprehensive income (loss)	3	(6)
Total stockholders’ equity	73,759	82,460
Total liabilities and stockholders’ equity	$ 76,575	$ 84,798