Collaboration arrangements and concentration of credit risk (Tables)

3 Months Ended

Mar. 31, 2018

Collaboration arrangements and concentration of credit risk

Schedule of collaboration and license revenue

	Three months ended March 31,
	2018		2017
Bristol Myers Squibb	$	3,478	$	1,507
Chiesi Farmaceutici S.p.A (terminated in 2017)		—		1,814
Total	$	3,478	$	3,321

Schedule of amounts owed in relation to collaboration

	March 31,		December 31,
	2018		2017
	in thousands
Bristol Myers Squibb	$	1,057	$	1,586