With interim phase 2 data, Takeda’s dengue vaccine casts shadow on Sanofi

Takeda's dengue vaccine induced sustained antibody responses in children, topline phase 2 data showed.

Takeda’s experimental dengue vaccine just became a clearer threat to Sanofi’s Dengvaxia, as the latest 18-month interim phase 2 data showed Takeda’s shot induced sustained antibody responses.

The ongoing phase 2 study was carried out on 1,794 children and adolescents aged 2 to 17 from the Dominican Republic, Panama and the Philippines, all dengue-endemic regions.

While it is still early in the process, data published in The Lancet Infectious Diseases showed antibody responses against all four serotypes of the virus, "regardless of previous dengue exposure," lasted past the 18-month topline data report point. Given that those never infected with dengue had higher seropositivity rate after a second dose, Takeda has confirmed TAK-003 as a two-dose regimen, administered three months apart.

Researchers will now follow with immunogenicity assessment through the study length of 48 months.

Although data from Takeda’s gigantic 20,100-subject phase 3 trial called TIDES are needed to confirm the vaccine’s efficacy, the phase results could send Sanofi—which has the first-ever approved dengue vaccine—fretting for a while.

RELATED: Sanofi's vaccines pick up pharma's slack—again—even as Dengvaxia languishes

Despite Sanofi investing heavily to get it to market, Dengvaxia hasn't been as popular as the drugmaker had expected. Initial sales in 2016 were only €55 million, far below executives’ earlier hope of €200 million.

And things aren’t turning any better this year. As three quarters have passed, Dengvaxia only generated €22 million in sales. The company cited difficult political and economic environment and low incidence in endemic regions as the reasons for the shot’s lackluster performance.

Application of Dengvaxia has also been limited, as WHO vaccine experts have cautioned its use in areas where there isn’t enough dengue activity, based on worries that harm from vaccination could outweigh its benefit, especially in people naïve to dengue infection.

While Sanofi Pastuer's efforts have faltered, Takeda is confident enough that in November it announced it is building a €100 million plant at its Singen, Germany-based site for the manufacturing of TAK-003. Results from the phase 3 trial are expected in late 2018.