License and Collaboration Agreements (Tables)

6 Months Ended

Jun. 30, 2016

Schedule of Revenue Recognized and Assets and Liabilities under Collaborative Arrangements

During the three and six months ended June 30, 2016 and 2015, the Company recognized revenue based on the following components of the Baxalta Agreement:

	Three Months Ended June 30,				Six Months Ended June 30,
(in thousands)	2016		2015		2016		2015
Proportional performance revenue recognition model	$	9,332	$	16,558	$	20,645	$	31,399
Substantive milestones		10,000		20,000		10,000		20,000
Total	$	19,332	$	36,558	$	30,645	$	51,399

As of June 30, 2016 and December 31, 2015, the Company maintained the following assets and liabilities related to the Baxalta Agreement:

(in thousands)	June 30, 2016		December 31, 2015
Accounts receivable, billed	$	642	$	1,336
Accounts receivable, unbilled		233		626
Deferred revenues		80,064		97,365