Sanofi Pasteur’s dengue vaccine demonstrates proof of efficacy

Sanofi Pasteur, the vaccines division of Sanofi (EURONEXT: SAN and NYSE: SNY), announced today that its tetravalent dengue vaccine candidate demonstrated proof of efficacy against dengue, a threat to almost 3 billion people, in the world’s first ever dengue efficacy trial conducted in Thailand, with excellent safety.

The vaccine generated antibody response for all four dengue virus serotypes. Evidence of protection was demonstrated against three of the four virus serotypes circulating in Thailand. Analyses are ongoing to understand the lack of protection for the fourth serotype in the particular epidemiological context of Thailand.

“Results of this first efficacy trial with Sanofi Pasteur’s dengue vaccine candidate represent a key milestone in the quest to develop a safe and efficacious human vaccine against dengue,” said Michel De Wilde, Ph.D., Executive Vice President, Research & Development, Sanofi Pasteur. “This is also an important development for global public health, since there is currently no specific treatment or prevention for dengue. We are fully committed to making dengue a vaccine preventable disease by bringing a safe and effective vaccine to people living in endemic regions of the world.”

Importantly, the results confirm the excellent safety profile of the vaccine candidate. The full data resulting from this first efficacy trial are currently under review by scientific and clinical experts, as well as public health officials. Detailed results of this study will be published in a peer-reviewed journal and presented to the scientific community later this year.

Large scale phase III dengue vaccine clinical studies with 31,000 participants are underway in 10 countries of Asia and Latin America. These studies will generate important additional data in a broader population and in a variety of epidemiological settings to demonstrate vaccine efficacy against the four circulating dengue virus serotypes.

About the Study

The study was conducted in 4,002 children aged 4 to 11 years, in partnership with the Mahidol University under the patronage of the Thai Ministry of Public Health in Muang district of the Ratchaburi Province. Sanofi Pasteur dengue vaccine candidate is a live attenuated vaccine. The vaccination schedule is 3 doses given 6 months apart (at 0, 6 and 12 months).

About Dengue

Dengue is a threat to nearly 3 billion people and a health priority in many countries of Latin America and Asia where epidemics occur.1 There is no specific treatment available for this disease. Dengue is expanding geographically; the recent outbreak in Florida shows that dengue can hit the continental U.S. beyond endemic areas in Hawaii and Puerto Rico.2

Dengue fever is a mosquito-borne disease caused by four types of dengue virus (types 1 to 4). Overall, the disease is a potential threat to almost half of the world’s population. Of the estimated 230 million people infected annually, two million–mostly children–develop dengue hemorrhagic fever (DHF), a severe form of the disease.6 DHF is a leading cause of hospitalization, placing tremendous pressure on strained medical resources and having a heavy economic and societal impact.

About Sanofi Pasteur’s Dengue Vaccine Clinical Program

Sanofi Pasteur’s investigational dengue vaccine – which targets all four virus types – has been evaluated in clinical studies (Phase I, II) in adults and children in the U.S., Asia and Latin America. Overall, an immune response against all four serotypes was observed after three doses of the vaccine. The vaccine is well tolerated with a similar safety profile after each dose.3

Large scale phase III dengue vaccine clinical studies in 31,000 adults and children are ongoing in Latin America (Mexico, Colombia, Honduras, Puerto Rico and Brazil) and in Asia (the Philippines, Vietnam, Malaysia, Indonesia, and Thailand). These studies follow the highest standards from the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). Sanofi Pasteur’s tetravalent dengue vaccine is the leading candidate dengue vaccine in development.4,5

The U.S. Food and Drug Administration (FDA) has granted fast-track designation to the company’s investigational dengue vaccine. The FDA fast-track designation recognizes that a dengue vaccine would address an important unmet medical need for a serious disease.

The Sanofi Pasteur investigational dengue vaccine is intended for the prevention of dengue disease in children and adults living in endemic areas of Asia and Latin America as well as for children and adults who are travelling to endemic countries, including expatriates and military personnel.

References

1. WHO Fact sheet N°117, March 2009 Dengue and dengue haemorrhagic fever http://www.who.int/mediacentre/factsheets/fs117/en/
2. Morbidity and Mortality Weekly Report (MMWR) Locally Acquired Dengue — Key West, Florida, 2009—2010 – May 21, 2010 / 59(19);577- 581
3. Saville et al, Clinical development of a tetravalent dengue vaccine for endemic areas, ICID Miami, March 2010; Lang et al, Toward a tetravalent dengue vaccine in Brazil, Tropical Medicine meeting, Iguacu Falls, March 2010
4. Dengue vaccine efficacy trials in progress, www.thelancet.com/infection, vol 9, November 2009
5. Jean Lang, Recent progress on Sanofi Pasteur’s dengue vaccine candidate, Journal of Clinical Virology 46, S2 (2009) 20-24
6. Beatty M Letson GW Margolis HS, Estimating the global burden of dengue, Am J Trop Med Hygiene 81, 5:231 200