Concentration of credit risk

3 Months Ended

Mar. 31, 2018

Concentration of credit risk

Concentration of credit risk

5.     Concentration of credit risk

In December 2009, we entered into a license, development and commercialization agreement with Lilly. In November 2009, we entered into a collaboration and license agreement with Novartis. The concentration of credit risk related to our collaborative partners is as follows:

	Percentage of Total
	Milestone Revenues for the
	Three Months Ended
	March 31,
	2018		2017
Collaboration Partner A	—	%	28	%
Collaboration Partner B	—	%	72	%

Collaboration Partner A and Collaboration Partner B comprised, in aggregate, 22% and 47% of the accounts receivable balance as of March 31, 2018 and December 31, 2017, respectively.

In November 2011, we began commercialization and distribution of JAKAFI to a number of customers. Our product revenues are concentrated in a number of these customers. The concentration of credit risk related to our JAKAFI product revenues is as follows:

	Percentage of Total Net
	Product Revenues for the
	Three Months Ended
	March 31,
	2018		2017
Customer A	22	%	27	%
Customer B	13	%	16	%
Customer C	14	%	13	%
Customer D	11	%	8	%

We are exposed to risks associated with extending credit to customers related to the sale of products. Customer A, Customer B, Customer C and Customer D comprised, in aggregate, 39% and 25% of the accounts receivable balance as of March 31, 2018 and December 31, 2017, respectively.

The concentration of credit risk relating to ICLUSIG product revenues or accounts receivable is not significant.