JAPANESE pharmaceutical giant Takeda is making rapid progress toward the development of a vaccine against the mosquito-borne dengue virus, with the Philippines among countries where it will be tested, the company’s director of its global dengue program said in a phone interview.
Dr. Derek Wallace, who heads the vaccine development program for Takeda, said one of the biggest challenges to creating a dengue vaccine is producing a stable compound that is effective against all four serotypes of the virus.
Citing World Health Organization (WHO) data, Wallace said that dengue causes an estimated 390 million infections and more than 20,000 deaths globally each year; it is considered the fastest-spreading mosquito-borne infection and is a leading cause of serious illness among children in some countries in Latin America and Asia.
“Four dengue serotypes circulate globally,” Wallace explained. “Infection with one dengue serotype confers life-long protection against re-infection with the same serotype, but only short-term protection against the other three serotypes, and sequential infections with different serotypes can potentially increase the risk of developing severe and lethal disease.”
Wallace further explained that researchers have a limited understanding of how the virus interacts with the immune system and how certain types of pre-existing immunity can make one more vulnerable to disease.
“It is clear that unmet needs in dengue prevention exist and we are working diligently to develop a vaccine that will protect all populations regardless of previous infection to the disease,” Wallace said.
In September, Takeda initiated a Phase III clinical trial, called the Tetravalent Immunization against Dengue Efficacy Study (TIDES), in nine countries across Latin America and Southeast Asia, including Brazil, Colombia, Dominican Republic, Nicaragua, Panama, the Philippines, Thailand, Sri Lanka and Vietnam.
TIDES is a controlled trial to investigate the efficacy, safety, and immunogenicity of two doses of Takeda’s tetravalent dengue vaccine candidate (TAK-003) administered 90 days apart in healthy children aged four to 16 years living in dengue endemic areas, Wallace explained.
“Our goal is to develop and test a vaccine that is safe for and protects populations and individuals at risk for symptomatic dengue, including children, regardless of whether they have previously been exposed to the virus,” he said.
“There are populations that are in need of a vaccine that protects against all four dengue serotypes in people of all ages, regardless of previous exposure, which our Phase III trial will examine,” Wallace said.
TAK-003 is based on a dengue serotype 2 virus which provides the genetic ‘backbone’ for all four vaccine viruses.
“Phase III clinical trials have been designed to assess vaccine efficacy against both moderate and severe dengue caused by each of the four dengue serotypes. The trial is on track and we expect to finish enrollment in the trial in the first half of 2017,” Wallace added.
TAK-003 would be the second dengue vaccine to be used in the Philippines after Sanofi Pasteur’s Dengvaxia. Dengvaxia has come under fire from some critics, who charge that the vaccine was rushed into use by the Department of Health before it was fully tested, an accusation health officials and the pharmaceutical company have strongly denied.
In addition to its work on the dengue vaccine, Takeda was earlier awarded a $19.8 million grant by the US Biomedical Advanced Research and Development Authority (BARDA), part of the US Department of Health and Human Services, to develop a vaccine against the Zika virus. Wallace explained the funding is intended for a Phase I clinical trial of the Zika vaccine, but that no timeline had been established yet.