License and Collaboration Agreements (Tables)

12 Months Ended

Dec. 31, 2016

Schedule of Revenue Recognized and Assets and Liabilities under Collaborative Arrangements

During the years ended December 31, 2016, 2015 and 2014, the Company recognized license and collaboration revenues based on the following components of the Baxalta Agreement:

	Years Ended December 31,
(in thousands)	2016		2015		2014
Proportional performance revenue recognition model	$	47,119	$	64,930	$	10,460
Substantive milestones		40,000		20,000		—
Total	$	87,119	$	84,930	$	10,460

During the year ended December 31, 2016, the Company also recognized royalty revenues of $0.2 million related to the Baxalta Agreement.

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

	December 31,
(in thousands)	2016		2015
Accounts receivable, billed	$	860	$	1,336
Accounts receivable, unbilled		581		626
Deferred revenues		56,779		97,365

Sanofi [Member]

Schedule of Revenue Recognized and Assets and Liabilities under Collaborative Arrangements

The Company recognized no revenue under the Sanofi agreement during the years ended December 31, 2016 or 2015. During the year ended December 31, 2014, the Company recognized revenue based on the following components of the Sanofi agreement:

(in thousands)	Year Ended December 31, 2014
Upfront payment	$	39,306
Milestone payment		16,377
Development services		18,904
Manufacturing services and other		17,709
Total	$	92,296