Sanofi Pasteur, the vaccines division of Sanofi , Wednesday announced that the final landmark phase III efficacy study of its dengue vaccine candidate in Latin America successfully achieved its primary clinical endpoint. Results showed an overall significant reduction of 60.8 percent of dengue disease cases in children and adolescents 9-16 years old after a three-dose vaccination schedule.  Importantly, efficacy was observed against each of the four dengue serotypes.


Additional observations of the results showed a clinically important reduction by 80.3 percent in the risk of hospitalization due to dengue during the study. The results also showed in the study population an efficacy against dengue hemorrhagic fever (DHF), the severe form of dengue,  which is consistent with the results released from Sanofi’s phase III dengue study in Asia. Lastly, the results suggest better protection in case of prior exposure to dengue.

Safety analyses (solicited reactions, unsolicited events and Serious Adverse Events SAEs) during the study showed similar reporting rates between the vaccine and control groups and are consistent with the favorable safety profile documented in previous studies (phase I, II, III).

A full analysis of the efficacy and safety data from the phase III study will be completed and reviewed by external experts before publication in a peer-reviewed scientific journal and presentation at the American Society of Tropical Medicine and Hygiene (ASTMH) Annual Meeting, 2-6 November 2014, in New Orleans, Louisiana, US.

Dengue is a threat to nearly half the world’s population and is a pressing public health priority in over 100 countries in the Americas and in Asia. A dengue vaccine would represent a major advance for the control of the disease and could be an important tool for reaching the WHO’s goal of reducing dengue mortality by at least 50 percent and morbidity by at least 25 percent by 2020.

“For the first time ever, after 20 years of research and industrial commitment, dengue is set to become a vaccine preventable disease,” said Olivier Charmeil, President and Chief Executive Officer, Sanofi Pasteur. “The data generated from our comprehensive research and clinical program involving 40,000 children, adolescents and adults from 15 countries, will be submitted to the health authorities in countries where dengue is a public health priority.”

Each year, an estimated 500,000 people, including children, have severe dengue requiring hospitalization, putting a huge strain on health care systems during outbreaks. Dengue has dramatically increased over the past 30 years with an acceleration over the last decade. Reported dengue cases in the Americas increased five-fold from 517,617 cases in 2003 to the unprecedented level of 2.3 million cases in 2013.

“These compelling phase III results demonstrate the efficacy and good safety profile of this vaccine candidate against dengue. For the first time, we have a vaccine candidate that has the potential to offer protection to people who are at risk of dengue,” commented Dr. Rivaldo Cunha, MD, Infectious Disease Specialist, Associate Professor, Faculty of Medicine Universidade de Mato Grosso do Sul, Brazil, and a principal investigator in the study.

“These new positive phase III results from Latin America are very encouraging because they are consistent with the results reported in July in the Asian phase III trial. Together, the results of these trials suggest that for the first time, a vaccine solution that can help control dengue, is on the horizon,” commented Professor Duane Gubler, Professor and Founder of the Signature Research Program on Emerging Infectious Diseases, Duke-NUS Graduate Medical School,
Singapore, and Chairman of the Partnership for Dengue Control. “Scientific and public health experts will now be in a position to define the best way to implement dengue vaccination effectively, based on the country epidemiology, the vaccine profile and the goals defined by WHO to reduce the disease burden by 2020.”