Concentration of Credit Risk

3 Months Ended

Mar. 31, 2013

Concentration of Credit Risk

Concentration of Credit Risk

4.     Concentration of Credit Risk

In December 2009, we entered into a license, development and commercialization agreement with Eli Lilly and Company (“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 Contract Revenues for the Quarters Ended, March 31,
	2013		2012
Collaboration Partner A	60	%	60	%
Collaboration Partner B	40	%	40	%

Collaboration Partner A and Collaboration Partner B comprised in the aggregate 24% and 73% of the accounts receivable balance as of March 31, 2013 and December 31, 2012, respectively.

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

	Percentage of Total Net Product Revenues for the Quarters Ended, March 31,
	2013		2012
Customer A	27	%	33	%
Customer B	18	%	26	%
Customer C	12	%	16	%
Customer D	12	%	12	%

We are exposed to risks associated with extending credit to specialty pharmaceutical customers related to the sale of products. Customer A, Customer B, Customer C and Customer D comprised in the aggregate 54% and 17% of the accounts receivable balance as of March 31, 2013 and December 31, 2012, respectively.