Concentration of credit risk (Tables)

6 Months Ended

Jun. 30, 2018

Concentration of credit risk

Schedule of concentration of credit risk related to collaborative partners

	Percentage of Total				Percentage of Total
	Milestone Revenues for the				Milestone Revenues for the
	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2018		2017		2018		2017
Collaboration Partner A	—	%	—	%	—	%	28	%
Collaboration Partner B	100	%	—	%	100	%	72	%

Schedule of concentration of credit risk related to specialty pharmacy customers

	Percentage of Total Net				Percentage of Total Net
	Product Revenues for the				Product Revenues for the
	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2018		2017		2018		2017
Customer A	21	%	23	%	21	%	25	%
Customer B	15	%	16	%	14	%	16	%
Customer C	14	%	13	%	14	%	13	%
Customer D	12	%	9	%	11	%	8	%