Condensed Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Operating activities:
Net loss	$ (3,534)	$ (4,157)
Adjustments to reconcile net loss to net cash used in operating activities:
Change in fair value of warrants		(5)
Depreciation	5	7
Amortization of license agreement	49	49
Stock-based compensation	274	254
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(126)	194
Accounts payable and accrued expenses	(10)	(636)
Net cash used in operating activities	(3,342)	(4,294)
Financing activities:
Proceeds from issuance of preferred stock, net of issuance costs	4,192
Proceeds from issuance of common stock, net of issuance costs	1,936	1,224
Net cash provided by financing activities	6,128	1,224
Increase (decrease) in cash and cash equivalents	2,786	(3,070)
Cash at beginning of period	4,946	9,972
Cash at end of period	7,732	6,902
Non-Cash investing and financing activities:
Conversion of preferred stock to common stock	$ 364