Consolidated Statements of Cash Flows (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities
Net loss	$ (14,493,000)	$ (11,307,000)
Adjustments required to reconcile net loss from operations to net cash used in operating activities:
Loss on warrant and derivative liabilities	11,795,000	8,773,000
Warrants issued to placement agents	213,000	0
Amortization of patents	8,000	8,000
Depreciation	58,000	18,000
Stock-based compensation	52,000	234,000
Changes in operating assets and liabilities net of acquisitions:
Accounts receivable	100,000	(4,000)
Accounts payable, accrued expenses and other	158,000	(1,365,000)
Accrued severance	(122,000)	0
Prepaid expenses and other current assets	(74,000)	(48,000)
Net cash used in operating activities	(2,305,000)	(3,691,000)
Cash flows from investing activities
Purchases of property and equipment	(35,000)	(229,000)
Net cash used in investing activities	(35,000)	(229,000)
Cash flows from financing activities
Net proceeds from March 2015 financing	12,384,000	0
Net cash provided by financing activities	12,384,000	0
Net increase (decrease) in cash and cash equivalents	10,044,000	(3,920,000)
Cash and cash equivalents, beginning of period	6,581,000	20,355,000
Cash and cash equivalents, end of period	16,625,000	16,435,000
Supplemental schedule of non-cash financing activities:
Accretion of Series B redeemable convertible preferred stock	338,000	314,000
Fair value of warrant liability upon issuance	$ 4,211,000	$ 0