World's most clinically advanced dengue vaccine candidate enters first phase 3 clinical study

First Phase 3 Study Underway in Australia

Sanofi Pasteur, the vaccines division of sanofi-aventis Group (EURONEXT: SAN and NYSE: SNY), announced today that its dengue vaccine is in final stage of clinical development. Sanofi Pasteur's dengue vaccine, the world's most clinically advanced dengue vaccine candidate, entered its first phase 3 clinical study in Australia.

This study is part of a global phase 3 clinical study program aimed at advancing the development of a novel vaccine for the prevention of dengue disease in children and adults. Currently, there is no specific treatment available for dengue fever, which is a threat to nearly three billion people and a public health priority in many countries of Latin America and Asia where epidemics occur.

Phase 3 studies are the ultimate steps in the clinical development of a vaccine before it is submitted to regulatory authorities for evaluation for market authorization. Sanofi Pasteur's candidate dengue vaccine is the first to reach phase 3 of clinical development.

"To address the global health challenge represented by dengue fever, we are conducting an unprecedented dengue vaccine research and development program as well as a scale up of the vaccine production," said Wayne Pisano, President and Chief Executive Officer of Sanofi Pasteur. "We are now entering the final laps of a long run that Sanofi Pasteur started almost 20 years ago. If successful, we are committed to introducing the vaccine in countries where dengue is of highest public health priority."

The study in Australia is the first to use dengue vaccine doses produced with industrial scale processes. The study is aimed at demonstrating that production of the vaccine at industrial scale will meet consistency criteria required for market authorization by regulatory authorities. Details of the phase 3 study in Australia as well as results of already completed studies are presented at the 59th annual conference of ASTMH (American Society of Tropical Medicine and Hygiene), held in Atlanta (Georgia, United States), November 3-7.