Sanofi Pasteur said today its dengue vaccine candidate met its primary endpoint in its second and final landmark Phase III efficacy study in Latin America.
Trial results showed an overall significant reduction of 60.8% of dengue disease cases in children and adolescents 9–16 years old after a three-dose vaccination schedule. Efficacy was also observed against each of the four dengue serotypes, the vaccines division of Sanofi said—though the efficacy per serotype (ST) varied widely, from 42.3% for ST2, rising to 50.3% for ST1, and to 74.0% for ST3 and 77.7% for ST4.
The results also showed a clinically significant 80.3% reduction in hospitalization risk due to dengue during the study—as well as better protection in cases of prior exposure to dengue, and efficacy against dengue hemorrhagic fever (DHF), the severe form of dengue, a result consistent with those released earlier this year from a Sanofi Pasteur Phase III dengue study in Asia.
“For the first time ever, after 20 years of research and industrial commitment, dengue is set to become a vaccine-preventable disease,” declared Olivier Charmeil, Sanofi Pasteur’s president and CEO, in a statement.
Charmeil added that the company’s research and clinical program involved 40,000 children, adolescents and adults from 15 countries. Data from that program will be submitted to the health authorities in countries where dengue is a public health priority, he said.
Sanofi Pasteur tested its dengue vaccine in a pair of Phase III trials involved more than a total 31,000 volunteers from Asia (Indonesia, Malaysia, the Philippines, Thailand and Vietnam) as well as Latin America and the Caribbean.
The Phase III Latin America-Caribbean study was designed to assess the efficacy of the dengue vaccine candidate after three vaccinations in preventing symptomatic virologically confirmed dengue cases.
The study was the second of two large-scale randomized, observer-blind, placebo-controlled multicenter trials. A total of 20,875 children aged 9 to 16 years from dengue-endemic areas within Brazil, Colombia, Mexico, Honduras, and Puerto Rico participated in the study. They were randomized to either receive three injections of the dengue vaccine or a placebo (2 to 1 ratio) at 0, 6, and 12 months.
Sanofi Pasteur said a full analysis of data from the phase III Latin American-Caribbean study will be reviewed by external experts before being published in a peer-reviewed scientific journal and presented at the American Society of Tropical Medicine and Hygiene Annual Meeting, to be held November 2–6 in New Orleans.
“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,” Duane Gubler, ScD., 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, said in a statement.
The World Health Organization (WHO) has set goals of reducing dengue mortality by at least 50%, and morbidity by at least 25%, by 2020.
“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,” Dr. Gubler added.