CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended		94 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013
Cash Flows From Operating Activities:
Net loss	$ (42,273)	$ (27,466)	$ (151,326)
Adjustments to reconcile net loss to net cash (used in) operating activities:
Depreciation	28	2	38
Loss on disposal of property and equipment		2	2
Stock-based compensation expense	3,258	1,345	8,742
Accretion of discount/premium on available-for-sale securities	45	(123)	(41)
Purchased in-process research and development			28,157
Change in fair value of derivative instruments-warrants	(633)	1,169	(4,254)
Changes in operating assets and liabilities:
Security deposit		(6)	(20)
Accounts payable and accrued expenses	4,575	2,228	11,042
Prepaid expenses and other current assets	(3,697)	(222)	(5,244)
Total Adjustments	3,576	4,395	38,422
Net Cash Used in Operating Activities	(38,697)	(23,071)	(112,904)
Cash Flows From Investing Activities:
Net liabilities assumed in connection with Exchange Agreement			(155)
Loans to related parties	(270)	(1,114)	(3,576)
Net purchases of available-for-sale securities	(50,000)	(20,000)	(70,000)
Additions to property and equipment	(615)		(657)
Net Cash Used in Investing Activities	(50,885)	(21,114)	(74,388)
Cash Flows From Financing Activities:
Proceeds from sale of common stock	94,734	51,750	211,168
Fees and expenses related to sale of common stock	(5,623)		(12,346)
Proceeds from exercise of stock warrants			415
Proceeds from exercise of stock options	119	(3,566)	119
Net Cash Provided by Financing Activities	89,230	48,184	199,356
Net (decrease)/ increase in cash and cash equivalents	(352)	3,999	12,064
Cash and cash equivalents at beginning of period	12,416	13,245
Cash and cash equivalents at end of period	12,064	17,244	12,064
Supplementary disclosure of cash flow information:
Cash paid for taxes	37	19	177
Supplementary disclosure of non-cash investing and financing activities:
Value of warrants classified as derivative liability-net	(3,575)	169	5,304
Value of common stock issued to induce stockholders to extend lock-up agreements			3,235
Recapitalization of Synergy	$ 4,904		$ 4,904