Takeda dengue vaccine meets main goal of trial; detailed results to come

CHICAGO - Takeda Pharmaceutical Co said on Tuesday that its experimental dengue vaccine appears to be safe and effective at preventing all four types of the mosquito-borne disease, meeting the main goal of the Japanese drugmaker's late-stage clinical trial.

The company said no significant safety concerns have emerged to date with vaccine called TAK-003.

Takeda did not disclose how the vaccine performed in people who had never been previously exposed to dengue, a group that experienced an increased risk of severe disease with Sanofi's Dengvaxia, the world's first dengue vaccine.

Sanofi had not collected blood samples on all subjects prior to beginning its trials. By the time the company confirmed the safety risk in 2017, the vaccine had already been used in more than 800,000 school children in the Philippines.

Takeda collected blood samples from all 20,000 children aged 4 to 16 from Asia and Latin America who participated in the Phase III TIDES trial. The study looked at the vaccine's safety and efficacy both in children who had been exposed to dengue and those who had not.

Takeda said it will release full details of how the vaccine fared at 15 months after the first dose in a peer-reviewed journal as quickly as possible.

The vaccine is administered in two doses three months apart. The first efficacy results include 11 months of follow-up.

Part 2 of the trial, which includes another six months of patient data, will review how the vaccine performed in each of the four different types of dengue, as well as its performance according to prior dengue exposure and the number of participants who contracted severe dengue.

Those two parts will form the basis of Takeda's filings seeking regulatory approvals. A third part of the study will evaluate long-term safety by following participants for another three years.

Dr. Rajeev Venkayya, president of Takeda's vaccines business, said in a phone interview that the upcoming publication will include preliminary data on the vaccine's performance against each dengue strain and data on prior dengue exposure of trial subjects.

The first safety problems with Sanofi's vaccine only became apparent in the third year after vaccination. After the Sanofi experience, some experts believe governments will require several years of follow-up data before incorporating Takeda's vaccine into mass vaccination campaigns.

Venkayya would not speculate on how much follow-up regulators or health authorities will require, but said, "I do think it's going to be more than one year."

While Sanofi's vaccine was based on a Yellow fever virus with dengue genes added in, TAK-003 is based on a weakened dengue 2 virus plus genes from the three other dengue types. Some infectious disease experts think the all-dengue design may trigger a broader immune response.

source: news.abs-cbn.com

Brazil approves dengue vaccine

Brazil became the first South American country Monday to authorize the world's first-ever dengue fever vaccine, which its French manufacturer says has the potential to save hundreds of lives here.

The tropical disease, a flu-like illness carried by mosquitoes, killed 839 people this year in Brazil and infected more than 1.5 million.

The sprawling South American country's decision to allow the new vaccine, called Dengvaxia, is a coup for French pharmaceutical giant Sanofi, which has now gotten the green light from regulators in three countries.

Mexico became the first country to allow the vaccine on December 9, and the Philippines followed suit last week.

Sanofi has requested regulatory approval in 20 countries across Asia and Latin America.

The vaccine is a potential "blockbuster" drug for the company, which estimates it could generate more than $1 billion a year in revenue.

The Brazilian government said regulators must still set a price per dose, a process that takes about three months on average.

A separate review would have to be carried out for the vaccine to be incorporated in the national vaccination plan, a health ministry official told AFP.

Scientists have long been stumped by dengue, which has four separate strains.

Clinical tests -- carried out on 40,000 people from 15 countries -- have found Dengvaxia can immunize two-thirds of people aged nine years and older, rising to 93 percent for the more severe form of the disease, dengue hemorrhagic fever.

Dengue infects as many as 400 million people per year, and the deadliest form kills 22,000 per year, says the World Health Organization.

It was once considered a disease of the tropics, endemic in only nine countries.

But globalization, urbanization, climate change and air travel are helping it to move into more temperate zones. It is now endemic in more than 100 countries.

The WHO says cases have risen 30-fold over the last 50 years, with more than half the world's population potentially at risk.

The 20 countries where Sanofi Pasteur hopes for regulatory approval have a total population of two billion people -- 200 million of them in Brazil.

source: www.abs-cbnnews.com