CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net loss	$ (4,903)	$ (4,231)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	72	197
Bad debt expense	24
Non-cash charges for stock-based compensation	699	388
Loss on disposal of long-lived assets		58
Changes in current assets and liabilities, net	(611)	(479)
Changes in non-current liabilities, net	2	78
Net cash used in operating activities	(4,717)	(3,989)
Cash flows from investing activities:
Purchases of property and equipment	(44)	(39)
Proceeds from the sale of property and equipment		5
Purchases of investment securities		(9,755)
Proceeds from maturities of investment securities	3,392	1,890
Net cash provided by/(used in) investing activities	3,348	(7,899)
Cash flows from financing activities
Proceeds from issuance of common stock, net of issuance costs	(20)	10,674
Net cash provided by/(used in) financing activities	(20)	10,674
Change in cash and cash equivalents	(1,389)	(1,214)
Beginning balance of cash and cash equivalents	7,968	5,249
Ending balance of cash and cash equivalents	$ 6,579	$ 4,035