License and Collaboration Agreements (Tables)

6 Months Ended

Jun. 30, 2013

License and Collaboration Agreements

Schedule of revenue recognized and assets and liabilities under collaborative arrangements

	Three months ended June 30,				Six months ended June 30,
(in thousands)	2012		2013		2012		2013
Upfront payment	$	1,250	$	1,250	$	2,500	$	2,500
Milestone payments	521		521		1,933		1,042
Development services	9,160		14,682		17,302		26,272
Manufacturing services and other	1,106		1,999		1,627		2,740
Total	$	12,037	$	18,452	$	23,362	$	32,554

(in thousands)	December 31, 2012		June 30, 2013
Accounts receivable, billed	$	1,577	1,789
Accounts receivable, unbilled	7,690		12,746
Deferred revenue	79,913		78,060