Concentration of credit risk

3 Months Ended

Mar. 31, 2019

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. In December 2018, we entered into a research collaboration and licensing agreement with Innovent Biologics, Inc. (“Innovent”). The concentration of credit risk related to our collaborative partners is as follows:


	Percentage of Total
	Milestone and Contract Revenues for the
	Three Months Ended
	March 31,
	2019		2018
Collaboration Partner A	—	%	—	%
Collaboration Partner B	—	%	—	%
Collaboration Partner C	100	%	—	%

Collaboration Partners A, B and C comprised, in aggregate, 26% and 42% of the accounts receivable balance as of March 31, 2019 and December 31, 2018, 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,
	2019		2018
Customer A	18	%	22	%
Customer B	15	%	13	%
Customer C	16	%	14	%
Customer D	12	%	11	%

We are exposed to risks associated with extending credit to customers related to the sale of products. Customers A, B, C and D comprised, in aggregate, 37% and 30% of the accounts receivable balance as of March 31, 2019 and December 31, 2018, respectively.

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