CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended			98 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Cash Flows From Operating Activities:
Net loss	$ (62,124)	$ (39,444)	$ (14,467)	$ (171,177)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	56	2	2	66
Loss on disposal of property and equipment		2		2
Stock-based compensation expense	4,614	2,515	822	10,098
Accretion of discount/premium on investment securities	59	(86)		(27)
Purchased in-process research and development				28,157
Change in fair value of derivative instruments-warrants	(149)	1,933	(5,257)	(3,770)
Changes in operating assets and liabilities:
Security deposit		(5)		(20)
Accounts payable and accrued expenses	7,084	4,442	(2,265)	13,551
Prepaid expenses and other current assets	(2,171)	(484)	(66)	(3,718)
Total Adjustments	9,493	8,319	(6,764)	44,339
Net Cash used in Operating Activities	(52,631)	(31,125)	(21,231)	(126,838)
Cash Flows From Investing Activities:
Net cash paid on Exchange Transaction				(155)
Loans to related parties	(270)	(1,764)	133	(3,576)
Purchases of available-for-sale securities	(30,000)	(20,000)		(50,000)
Additions to property and equipment	(615)	(28)		(657)
Net Cash (used in) /provided by Investing Activities	(30,885)	(21,792)	133	(54,388)
Cash Flows From Financing Activities:
Proceeds of sale of common stock	94,734	55,862	34,369	211,168
Fees and expenses related to sale of common stock	(5,623)	(3,774)	(2,148)	(12,346)
Proceeds from exercise of warrants			415	415
Proceeds from exercise of stock options	119			119
Net Cash provided by Financing Activities	89,230	52,088	32,636	199,356
Net increase (decrease) in cash and cash equivalents	5,714	(829)	11,538	18,130
Cash and cash equivalents at beginning of period	12,416	13,245	1,707
Cash and cash equivalents at end of period	18,130	12,416	13,245	18,130
Supplementary disclosure of cash flow information:
Cash paid for taxes	81	50	38	221
Supplementary disclosure of non-cash investing and financing activities:
Value of warrants classified to derivative liability-net	(3,575)		5,094	5,304
Value of common stock issued to induce stockholders to extend lock-up agreements				3,235
Recapitalization of Synergy	$ 4,904			$ 4,904