CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended		91 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013
Cash Flows From Operating Activities:
Net loss	$ (28,736)	$ (17,581)	$ (137,789)
Adjustments to reconcile net loss to net cash (used in)/provided by operating activities:
Depreciation		1	10
Loss on disposal of property and equipment		2	2
Stock-based compensation expense	2,168	792	7,652
Accretion of discount/premium on investment securities	98	(160)	12
Purchased in-process research and development			28,157
Change in fair value of derivative instruments-warrants	(710)	1,309	(4,331)
Changes in operating assets and liabilities:
Security deposit		(6)	(20)
Accounts payable and accrued expenses	(623)	2,173	5,844
Prepaid expenses and other current assets	(802)	(345)	(2,349)
Total Adjustments	131	3,766	34,977
Net Cash Used in Operating Activities	(28,605)	(13,815)	(102,812)
Cash Flows From Investing Activities:
Net liabilities assumed in connection with Exchange Agreement			(155)
Loans to related parties	(270)	(395)	(3,576)
Purchases of available-for-sale securities	(64,000)	(20,000)	(84,000)
Additions to property and equipment	(459)		(501)
Net Cash Used in Investing Activities	(64,729)	(20,395)	(88,232)
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)	(3,358)	(12,346)
Proceeds from exercise of stock warrants			415
Proceeds from exercise of stock options	119		119
Net Cash Provided by Financing Activities	89,230	48,392	199,356
Net (decrease) increase in cash and cash equivalents	(4,104)	14,182	8,312
Cash and cash equivalents at beginning of period	12,416	13,245
Cash and cash equivalents at end of period	8,312	27,427	8,312
Supplementary disclosure of cash flow information:
Cash paid for taxes	27	12	167
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