Sanofi Posts Positive Data For Dengue Vaccine Candidate

Sanofi’s vaccine division Sanofi Pasteur announced positive results from its first landmark Phase III dengue vaccine efficacy trial. Results show an 88.5 percent reduction of dengue hemorrhagic fever. In children aged 2-14 years, the drug was 56.5 percent effective against symptomatic dengue following a three-dose vaccination schedule.

Data also showed a 67 percent — almost two-thirds — reduction in risk of hospitalization due to dengue after administration of the vaccine. Sanofi Pasteur said that its vaccine candidate’s safety profile is favorable and consistent with those documented in previous studies.

Two pivotal Phase III studies enrolled more than 31,000 people from five Asian countries (the Philippines, Indonesia, Malaysia, Thailand, and Vietnam) and five Latin American countries (Colombia, Brazil, Honduras, Mexico and Puerto Rico) to investigate the efficacy and immunogenicity of the vaccine candidate.

“The high efficacy observed against severe dengue and the reduction of hospitalization by two thirds is an extremely important public health outcome. Furthermore this dengue vaccine continues to meet the highest safety expectations, which is very reassuring,” said Professor Duane Gubler, Chairman of the Partnership for Dengue Control, Professor and Founding Director of the Signature Research Program on Emerging Infectious Diseases at Duke-NUS Graduate Medical School in Singapore.

Dengue threatens nearly half of the global population and is a significant health burden in many Asian and Latin American countries where epidemics take place. Every year, half a million people including children are hospitalized due to severe dengue, pushing hospitals and health care systems to the limit during dengue outbreaks.

John Shiver, SVP in R&D at Sanofi Pasteur, said, “These pivotal phase III vaccine efficacy study results take us closer to our ambition to bring the first vaccine against dengue to the world. …These findings are an important stride towards meeting the WHO’s strategic goals of reducing dengue mortality by half and morbidity by at least 25 percent by 2020.”

Findings from the trial were published in The Lancet. However, questions remain as to why the vaccine failed to rein in dengue’s serotype 2 strain in a 2012 study in Thailand. Serotype 2 was the most prevalent strain of the disease at the time of the trial. This time around, serotype 2 was less prevalent among patient populations and the vaccine scored a higher overall efficacy rate. Authorities need to determine dengue’s threshold incidence before investing in potentially expensive vaccination programs, said Annelies Wilder-Smith of Singapore's Nanyang Technological University, author of an accompanying commentary to the Lancet study.