Bayer and Janssen link with Portola for Xarelto antidote

Germany’s Bayer (BAYN: DE) and Janssen Pharmaceuticals, a part of US health care giant Johnson & Johnson (NYSE: JNJ), have entered into a clinical collaboration with USA-based Portola Pharmaceuticals to evaluate the safety of PRT4445, an investigational antidote for Factor Xa inhibitors, in healthy volunteers who have been administered their oral anticoagulant Xarelto (rivaroxaban).

Bayer Healthcare and Janssen 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. The aim is to assuage doctors’ concerns about bleeding or sudden need for surgery, and the lack of an antidote to Xarelto.

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. No agents are approved to reverse the activity of Factor Xa inhibitors.