Concentrations of Credit Risk

12 Months Ended

Dec. 31, 2018

Note 5. Concentrations 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 and
	Contract Revenues for the
	Years Ended,
	December 31,
	2018		2017		2016
Collaboration Partner A	33	%	37	%	40	%
Collaboration Partner B	67	%	63	%	60	%

Collaboration Partner A and Collaboration Partner B comprised, in the aggregate, 42% and 47% of the accounts receivable balance as of December 31, 2018 and 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
	Years Ended,
	December 31,
	2018		2017		2016
Customer A	20	%	24	%	25	%
Customer B	14	%	15	%	17	%
Customer C	15	%	13	%	13	%
Customer D	11	%	8	%	9	%

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 the aggregate, 30% and 25% of the accounts receivable balance as of December 31, 2018 and 2017, respectively.

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