BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 26,178	$ 51,722
Short-term investments	3,922	4,474
Prepaid expenses and other current assets	199	1,571
Total current assets	30,299	57,767
Property and equipment, net	1,148	31
Investments		1,488
Other assets		362
Total assets	31,447	59,648
Current liabilities:
Current portion of notes payable	3,500	2,128
Accounts payable	2,809	3,146
Accrued expenses	1,775	2,161
Total current liabilities	8,084	7,435
Notes payable	1,743	5,236
Other long-term liabilities	141	56
Total liabilities	9,968	12,727
Commitments and contingencies (Note 8)
Stockholders' equity:
Preferred stock, $0.001 par value; 25,000,000 shares authorized, no shares issued and outstanding
Common stock, $0.001 par value; 100,000,000 shares authorized, 19,734,351 issued and 19,705,120 outstanding at December 31, 2016 and 19,420,086 issued and 19,390,855 outstanding at December 31, 2015	20	19
Additional paid-in capital	147,288	144,088
Treasury stock at cost, 29,231 shares at December 31, 2016 and 2015
Accumulated deficit	(125,829)	(97,186)
Total stockholders’ equity	21,479	46,921
Total liabilities and stockholders’ equity	$ 31,447	$ 59,648