NIH-developed dengue vaccine protects all patients in challenge study

As Sanofi ($SNY) works to gain traction for the launch of its world-first dengue vaccine, a potential competitor may be building its case. This week, the National Institutes of Health announced that a candidate developed by scientists there posted "very encouraging" results, according to the team's lead scientist.

Stephen Whitehead

The vaccine, dubbed TV003, protected all patients in a small human challenge, while all patients who were given a placebo injection developed dengue infection. Published in Science Translational Medicine and announced this week, the results "informed the recent decision by officials at Brazil's Butantan Institute" to move the vaccine to a large Phase III trial in the endemic nation, team lead Stephen Whitehead said in a statement.

For the trial, researchers enrolled 48 healthy adults to receive either the experimental vaccine or a placebo. Of the 41 who returned for a dengue challenge, all 21 patients who received the vaccine didn't develop viremia--presence of virus in the blood--while all 20 patients who received placebo did.

The group used a genetically modified version of a dengue-2 serotype virus and is now working on a human challenge model using a modified dengue serotype-3 virus for future work. The NIH noted that FDA scientists also contributed in developing the vaccine.

Last month, Brazil dedicated $24.8 million to fund the Phase III trial in 17,000 people, according to reports, despite the fact that the country has already approved Dengvaxia. The dengue- and Zika-stricken nation hasn't announced plans to incorporate Dengvaxia into a national immunization campaign.

Sanofi's vaccine began gathering its first approvals at the end of last year in endemic nations. Over the course of this year, the French pharma anticipates the launch to transition more and more into efforts around local immunization campaigns, which are seen as crucial for the rollout.

The Butantan Institute has licensed the NIH-developed Phase III candidate--which could pose a threat to Sanofi's vaccine--while Takeda's DenVAX is also expected to compete for market share by 2020.

The NIH team says it's working on leveraging its dengue work into Zika vaccine R&D efforts.

- here's the announcement