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

Race for Zika vaccine gathers momentum as virus spreads

Vaccine is seen as months, if not years, away
U.S. CDC activates Zika emergency response center
Geneva-based WHO plans emergency meeting Monday

Companies and scientists are racing to create a Zika vaccine as concern grows over the mosquito-borne virus that has been linked to severe birth defects and is spreading quickly through the Americas.

Zika is now present in 23 countries and territories in the Americas. Brazil, the hardest-hit country, has reported around 3,700 cases of the devastating birth defect called microcephaly that are strongly suspected to be related to Zika.

The Geneva-based World Health Organization (WHO), stung by criticism that it reacted too slowly to West Africa's Ebola epidemic, convenes an emergency meeting on Monday to help determine its response to the spread of the virus.

The U.S. Centers for Disease Control and Prevention has activated an emergency operations center staffed around the clock to address Zika, agency officials told Reuters.

On Thursday, the WHO said as many as 4 million people in the Americas may become infected by Zika, adding urgency to the research efforts. Vaccine developers made clear a vaccine for widespread public use is at least months, if not years, away.

The closest prospect may be from a consortium including drugmaker Inovio Pharmaceuticals Inc that could have a vaccine ready for emergency use before year-end, according to one of its lead developers. Inovio's share price gained more than 15 percent in Friday trading.

Canadian scientist Gary Kobinger told Reuters on Thursday the first stage of testing on humans could begin as early as August. If successful, the vaccine might be used during a public health emergency by October or November, said Kobinger, who helped develop a trial vaccine for the Ebola virus.

Privately owned vaccine developer Hawaii Biotech Inc said it began a formal program to test a Zika vaccine last fall as the virus started to gain traction in Brazil, although it has no timetable yet for clinical trials.

"Right now, we are in the pre-clinical stage, as I suspect everyone is," Chief Executive Officer Dr. Elliot Parks told Reuters.

Another private vaccine developer, Boston-based Replikins Ltd, said it was preparing to start animal studies on a Zika vaccine in the next 10 days. Data from the trials on mice and rabbits would likely be out in the next couple of months, Replikins Chairman Samuel Bogoch told Reuters.

"No one has the $500 million on hand to take it (a vaccine) all the way to human trials. Somewhere along the course we hope to have big pockets join us," Bogoch said.

'FIGHT THE MOSQUITO'

Zika had been viewed as a relatively mild illness until Brazilian health officials identified it as a matter of concern for pregnant women. While a direct causal relationship has not been established, scientists strongly suspect a link between Zika and thousands of children born in Brazil with abnormally small heads, brain defects and impaired vision.

There is no treatment for Zika infection.

Efforts to combat Zika are focused on protecting people from being bitten and on eradicating mosquitoes, a tough task in many parts of Latin America, where people live in poverty and there are plentiful breeding grounds for the insect.

"We do not have a vaccine for Zika yet. The only thing we can do is fight the mosquito," Brazilian President Dilma Rousseff said on Friday, reiterating her call for a national eradication effort.

Rousseff said tests for the development of a vaccine would begin next week at the Butantan Institute, one of Brazil's leading biomedical research centers in Sao Paulo.

U.S. President Barack Obama spoke on Friday with Rousseff about the spread of the virus, the White House said.

"The leaders agreed on the importance of collaborative efforts to deepen our knowledge, advance research and accelerate work to develop better vaccines and other technologies to control the virus," the White House said in a statement.

Zika has hit Brazil just as it prepares to host the Olympic Games in Rio de Janeiro on Aug. 5-21, an event that draws hundreds of thousands of athletes, team officials and spectators. The International Olympic Committee (IOC) assured teams on Friday the Olympics would be safe from Zika, but urged visitors to carefully protect themselves.

U.S. lawmakers have begun to press the Obama administration for details of its response to Zika. At least 31 people in the country have been infected, all of them after travel to affected countries.

The U.S. Senate Health, Education, Labor and Pensions Committee is planning a hearing on Zika "very soon," said Republican Senator Lamar Alexander of Tennessee, who called the threat posed by the virus to the United States a "big concern."

Dr. Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Disease, said he did not expect the United States to be hit hard like other some countries in South America and the Caribbean.

"We prepare for the possibility of a major outbreak but we believe it is unlikely to happen," Fauci said.

(Reporting by Rod Nickel in Winnipeg, Manitoba; and Natalie Grover in Bengaluru; Additional reporting by Amrutha Penumudi in Bengaluru; Julie Steenhuysen in Chicago, Toni Clarke in Washington, Karolos Grohmann in Berlin, Anthony Boadle in Brasilia, Jeffrey Dastin in New York; Writing by Frances Kerry; Editing by Will Dunham and Lisa Shumaker)

source: www.abs-cbnnews.com