Consolidated Statements of Cash Flows (unaudited) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating activities
Net loss	$ (10,575,000)	$ (5,515,000)
Reconciliation of net loss to net cash used in operating activities:
Depreciation	21,000	21,000
Amortization of premium/discount on available-for-sale securities	18,000	21,000
Gain on sale of fixed assets		(7,000)
Accretion of discount & debt issuance cost of convertible notes payable	742,000	146,000
Stock-based compensation	234,000	126,000
Change in fair value of investor rights/obligation	5,344,000
Change in fair value of derivative liability	81,000	20,000
Changes in:
Prepaid expenses and other current assets	(2,234,000)	128,000
Interest receivable	(13,000)	15,000
Accounts payable and accrued expenses	1,275,000	111,000
Accrued interest payable	115,000	25,000
Deferred revenue from sale of acquisition option to acquire company	(2,948,000)
Net cash used in operating activities	(7,940,000)	(4,909,000)
Investing activities
Purchases of available-for-sale investments	(19,697,000)	(1,510,000)
Proceeds from maturities of available for sale investments	3,580,000	6,550,000
Purchase of property and equipment	(45,000)	(1,000)
Sale of property and equipment		7,000
Net cash (used in) provided by investing activities	(16,162,000)	5,046,000
Financing activities
Proceeds from issuance of Series D preferred stock	25,000,000
Issuance costs for preferred stock	(452,000)
Proceeds from issuance of convertible notes payable		4,339,000
Payments for debt issuance costs		(46,000)
Exercise of stock options		19,000
Net cash provided by financing activities	24,548,000	4,314,000
Increase in cash and cash equivalents	446,000	4,451,000
Cash and cash equivalents, beginning of period	2,793,000	2,409,000
Cash and cash equivalents, end of period	3,239,000	6,860,000
Supplemental disclosure of non-cash investing and financing activities
Accretion of redeemable convertible preferred stock to redemption value	5,686,000	4,579,000
Fair value of embedded derivative contained within convertible notes payable		1,443,000
Conversion of convertible notes, including accrued interest, into Series D Redeemable Convertible Preferred Stock	4,565,000
Early Exercise of Stock Options [Member]
Financing activities
Exercise of stock options		$ 2,000