Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities
Net Loss	$ (27,758)	$ (17,828)
Adjustments:
Depreciation and amortization	2,781	368
Stock compensation expense	3,067	292
Acquired in-process research and development	344
Revaluation of preferred stock warrants		183
Loss on disposal of property and equipment	32
Amortization of debt issuance costs		29
Changes in assets and liabilities:
Accounts receivable	(411)	770
Taxes receivable, prepaid expenses, other current assets and other assets	501	(161)
Accounts payable	(273)	524
Accrued expenses and other liabilities	(655)	1,077
Deferred revenue	4,947	2,927
Net cash used in operating activities	(17,425)	(11,819)
Cash flows from investing activities
Capital expenditures	(2,670)	(527)
Purchase of in-process research and development and other assets	(394)
Net cash used in investing activities	(3,064)	(527)
Cash flows from financing activities
Proceeds from issuance of common stock, net of issuance costs	192,736
Proceeds from issuance of convertible notes		12,500
Payments of debt issuance costs		(34)
Proceeds from exercise of stock options	933	106
Net cash provided by financing activities	193,669	12,572
Effect of exchange rate on cash	(5)	(1)
Net increase in cash and equivalents	173,175	225
Cash and equivalents at the beginning of period	60,232	14,715
Cash and equivalents at the end of period	$ 233,407	$ 14,940