Dengue Vaccine Candidate Meets Primary Efficacy Endpoint in Phase 3 Study

Takeda Pharmaceutical Company Limited has announced that an investigational dengue vaccine has met the primary efficacy endpoint in an ongoing Phase 3 trial. In addition, the candidate has been found to be well tolerated with no significant concerns to date, thus far.

TAK-003 is unique in that it is a tetravalent dengue vaccine that is based on a live-attenuated dengue serotype 2 virus, which provides the genetic “backbone” for all 4 virus serotypes.

The prevalence of individual serotypes of dengue varies across different areas, seasons, and over the course of time. Recovery from a dengue infection provides lifelong immunity against only that particular infection’s serotype; therefore, later exposure of any of the remaining serotypes is associated with an increased risk of severe disease.

The first analysis of the Tetravalent Immunization against Dengue Efficacy Study (TIDES) trial has reported that TAK-003, has been shown to be efficacious in preventing dengue fever caused by any of the 4 serotypes of the dengue virus.

The TIDES trial is the company’s largest investigational clinical trial to date and has enrolled over 20,000 healthy individuals between the ages of 4-16 who live in dengue-endemic areas in Asia and Latin America. The double-blind, randomized, and placebo-controlled study is assessing the efficacy, safety, and immunogenicity of 2 doses of the vaccine candidate in both dengue exposed and naïve individuals.

Upon enrollment into the trial, study participants were randomly assigned to receive either a 0.5mL dose of the candidate or placebo by subcutaneous injection on Day 1 and Day 90. Baseline blood samples were collected from all participants to evaluate safety and efficacy based on serostatus. Safety monitoring is being conducted on an ongoing basis by an independent data monitoring committee

The study comprises 3 parts, the first of which evaluated vaccine efficacy and safety through 15 months following the first dose. The second part will follow the participants for an additional 6 months to complete the assessment of the secondary endpoints by serotype, baseline serostatus, and severity. The third part of the study will consist of determining long-term safety by following participants for an additional 3 years.

According to Takeda, the TIDES trial will continue and additional results are expected later this year, along with results from other Phase 3 studies assessing TAK-003. The findings will be published in a peer review journal and the company continues to advance development and manufacturing to support a future global launch of the vaccine.

Data from first and second part of the trial will form the basis for filing for licensure, as the vaccine is currently not licensed anywhere in the world.

In phase 1 and 2 studies in children and adolescents, the candidate vaccine was found to induce immune responses against all 4 dengue serotypes, in both seropositive and seronegative participants and was also found to be generally safe and well tolerated.

Takeda is also developing vaccines to address other high-priority infectious diseases, which include Zika, norovirus, and polio.