CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) (USD $) In Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Share-based compensation expense, Research and development	$ 1,375	$ 944	$ 2,211	$ 2,483
Share-based compensation expense, General and administrative	$ 1,758	$ 1,541	$ 2,688	$ 4,070

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