Accrued expenses and other current liabilities (Tables)

12 Months Ended

Dec. 31, 2012

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities are comprised of the following (in thousands):

	December 31,
	2011		2012
Salary and related expenses	$	8,997	$	10,074
Research and clinical trial costs		2,383		5,995
Accrued interest		8,262		4,533
Construction in progress		—		3,878
Other		1,094		1,297
Accrued expenses and other current liabilities	$	20,736	$	25,777