Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 36,392	$ 40,031
Available-for-sale investments	4,925	25,232
Prepaid expenses and other current assets	1,438	1,345
Total current assets	42,755	66,608
Property and equipment, net	372	224
Other non-current assets	393	706
Total assets	43,520	67,538
Current liabilities:
Accounts payable	556	1,020
Accrued expenses	4,523	2,576
Other current liabilities		537
Total current liabilities	5,079	4,133
Total liabilities	5,079	4,133
Commitments and contingencies (Note 7)
Stockholders’ equity:
Preferred stock, $0.001 par value per share; 10,000,000 shares authorized, no shares issued and outstanding at December 31, 2016 and 2015	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized at December 31, 2016 and 2015; 16,603,559 and 16,501,500 shares issued and outstanding at December 31, 2016 and 2015, respectively	17	16
Additional paid-in capital	198,201	194,651
Accumulated deficit	(159,777)	(131,251)
Accumulated other comprehensive loss		(11)
Total stockholders’ equity	38,441	63,405
Total liabilities and stockholders’ equity	$ 43,520	$ 67,538