Item 1.01 Entry into a Material Definitive Agreement.

On September 24, 2009, we entered into an amendment to our Research Collaboration and License Agreement with AstraZeneca AB, dated January 30, 2007. We previously filed that agreement as Exhibit 10.2 of our quarterly report on Form 10-Q for the quarter ended December 31, 2006, filed with the SEC on February 8, 2007, and filed previous amendments to that agreement as Exhibit 10.28 of our annual report on Form 10-K for the year ended June 30, 2008, filed with the SEC on September 29, 2008, and as Exhibit 10.2 of our quarterly report on Form 10-Q for the quarter ended December 31, 2008, filed with the SEC on February 13, 2009. Under the amendment, we will receive an up-front payment of $2.5 million and, subject to completion of certain tasks relating to the program, $2.5 million in the first quarter of calendar year 2010. As part of the amendment, terms of the agreement relating to milestone payments and royalty rates were restructured, such that we are eligible for milestone payments totaling up to $145.2 million, with up to $85.2 million contingent upon development and regulatory milestones and the balance on achievement of sales targets, plus stepped royalties on product sales. We have also agreed to conduct additional clinical studies for AstraZeneca, which will be under a clinical trial sponsored research agreement to be funded by AstraZeneca.