Bayer AG's Bayer HealthCare and Janssen Pharmaceuticals, Inc. Announce Clinical Collaboration Agreement With Portola Pharmaceuticals, Inc.

Bayer AG's Bayer HealthCare and Janssen Pharmaceuticals, Inc. announced a clinical collaboration agreement with Portola Pharmaceuticals, Inc. (Portola) to evaluate the safety of PRT4445, an investigational antidote for Factor Xa inhibitors, in healthy volunteers who have been administered the oral anticoagulant Xarelto (rivaroxaban). This proof-of-concept study, comprising multiple cohorts with different anticoagulants being tested, is expected to be completed in the second half of 2013.The study is designed to evaluate the safety of multiple dosage strengths of PRT4445 in combination with Xarelto in order to determine the dose of PRT4445 that would be required to reverse the anticoagulant activity of Xarelto in emergency situations. Standard clinical measures are currently employed to manage these patients and events. Bayer HealthCare and Janssen Pharmaceuticals, Inc. will make an undisclosed payment to Portola and will provide development and regulatory guidance for the study. Portola retains all global development and commercialization rights for PRT4445.