Cubist Pharmaceuticals, Inc and XTL Biopharmaceuticals Ltd have reached a consensus for the worldwide development and commercialisation of XTLbio's investigational monoclonal antibody product currently known as HepeX-B. The product is in a phase 2b study for the prevention of re-infection by the hepatitis B virus (HBV) in liver transplant patients.

The companies will continue the ongoing international phase 2b study and, if successful, will continue late-stage clinical development of the product candidate. Cubist will fund the development costs of HepeX-B and will be solely responsible for registration and commercialization of the product worldwide.

"This commercial agreement represents a significant achievement for XTLbio," said Dr. Martin Becker, XTLbio's president and CEO. "We feel this agreement not only validates our proprietary technology, but also would provide us with a revenue stream should HepeX-B ultimately be approved," he added.

Michael W. Bonney, President & CEO of Cubist comments, "HepeX-B represents an exciting development opportunity for Cubist. We believe that HepeX-B has the potential to become the new standard of care for the prevention of HBV re-infection in liver transplant patients."

HBV-diseased livers are currently estimated to represent 5 per cent of all liver transplants in the U.S., or between 200 and 300 liver transplants per year. HepeX-B is a combination of two fully human monoclonal antibodies, selected using XTLbio's pre-clinical Trimera model, that target HBV surface antigens. In clinical studies, HepeX-B maintained serum levels similar to or higher than the current first-line treatment, HBIg, using 1,000 times less drug.

Cubist Pharmaceuticals, Inc. is a biopharmaceutical company focused on the development of anti-infective products. XTL Biopharmaceuticals Ltd is also a biopharmaceutical company developing drugs against hepatitis.