BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 39,102	$ 51,722
Short-term investments	4,917	4,474
Prepaid expenses and other current assets	385	1,571
Total current assets	44,404	57,767
Property and equipment, net	1,017	31
Investments	744	1,488
Other assets		362
Total assets	46,165	59,648
Current liabilities:
Current portion of notes payable	3,627	2,128
Accounts payable	2,824	3,146
Accrued expenses	3,745	2,161
Total current liabilities	10,196	7,435
Notes payable	3,489	5,236
Other long-term liabilities	149	56
Total liabilities	13,834	12,727
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, 19,538,451 issued and 19,509,220 outstanding at June 30, 2016 and 19,420,086 issued and 19,390,855 outstanding at December 31, 2015	20	19
Additional paid-in capital	145,662	144,088
Treasury stock at cost, 29,231 shares at June 30, 2016 and December 31, 2015
Accumulated deficit	(113,351)	(97,186)
Total stockholders’ equity	32,331	46,921
Total liabilities and stockholders’ equity	$ 46,165	$ 59,648