Takeda’s dengue vaccine safe

Takeda’s dengue vaccine seems safe with no prior virus exposure
Appears unaffected by serious safety issue affecting Sanofi rival

Takeda says new data shows its candidate vaccine for dengue fever TAK-003 is effective, and crucially doesn’t seem to be affected by a serious safety issue that has affected Sanofi’s rival shot Dengvaxia.

The new analysis from the 20,000-patient TIDES in dengue-endemic areas in Latin America and Asia reveal an overall protection rate of just over 80% with the vaccine in children aged four to 16 who were assessed 12 months after a two-dose course.

Similar protection was seen in individuals regardless of whether or not they had been previously infected with dengue, and there was no sign in the trial that unexposed, seronegative patients fared more poorly, according to results published in the New England Journal of Medicine.

The researchers note in the paper that Dengvaxia was approved on the basis of a 56-61% overall protection rate among children in Asia and Latin America.

In 2017, the World Health Organization (WHO) said that Dengvaxia should not be administered to people who have not previously been infected with dengue virus, because it seemed to be linked to an increase in hospitalisation and severe illness among children in that group.

The move followed the confirmation by Sanofi that it had observed an increase in serious illness in children receiving the vaccine in the Philippines, which subsequently halted a Dengvaxia vaccination programme.

Studies indicated that increased risk of severe dengue disease in people who have never been infected affects about 15% of vaccinated individuals.

Since then sales of Dengvaxia – once tipped to become a blockbuster – have been too low to warrant a separate line in Sanofi’s financial results statements.

Dengue is a mosquito-borne disease that has been designated by the WHO as a top ten threat to global health this year, and Dengvaxia is the first vaccine against the virus to have reached the market.

Nearly half of the world’s population lives in dengue-endemic areas in more than 100 countries worldwide, and there are estimated to be around 390 million cases of infection with the virus each year.

The NEJM study shows some variation for TAK-003 depending on the strain of dengue virus, performing best against DENV-2 (97.7% efficacy), followed by DENV-1 (73.7%) and DENV-3 (62.6%), with insufficient data to give a figure for DENV-4.

It’s still too early however to say that TAK-003 sidesteps the safety issue, which is thought to occur when patients have a strong antibody response to one strain but are subsequently infected with one of the other three types.

The NEJM authors note that while hospitalisations were reduced 95.4% with TAK-003, most cases resulting in hospitalisation (43 of 58) involved DENV-2 and the tiny number caused by other strains means no meaningful conclusion can be drawn.

Nevertheless for now it’s so far, so good for Takeda’s vaccine, and the company says it hopes to move ahead with regulatory submissions.

It’s also investing in production capacity for TAK-003, and this week opened a €130m plant in Germany that it says will help it meet global demand at launch.

Source:   https://www.pmlive.com/pharma_news/takedas_dengue_vaccine_seems_safe_with_no_prior_virus_exposure_1315891