Takeda Pharmaceutical Company Limited announced that the pivotal Phase 3 trial of its dengue vaccine candidate met the primary efficacy endpoint. This first analysis of the Tetravalent Immunization against Dengue Efficacy Study (TIDES) trial showed that the company’s investigational live-attenuated tetravalent dengue vaccine (TAK-003) was efficacious in preventing dengue fever caused by any of the four serotypes of the virus. While review of the extensive data set is ongoing, TAK-003 was well tolerated with no significant safety concerns to date. The TIDES trial is continuing and additional results are expected later this year, along with results from other Phase 3 studies.1 The TIDES trial, company’s larger interventional clinical trial to date, enrolled over 20,000 healthy children and adolescents ages four to 16 years living in dengue-endemic areas. The study was designed to evaluate the efficacy, safety and immunogenicity of two doses of TAK-003, in both dengue exposed and naïve individuals.1 The TIDES trial, company’s largest interventional clinical trial to date, enrolled over 20,000 healthy children and adolescents ages four to 16 years living in dengue-endemic areas. The study was designed to evaluate the efficacy, safety and immunogenicity of two doses of TAK-003, in both dengue exposed and naïve individuals.1 The double-blind, randomized and placebo-controlled Phase 3 TIDES trial is evaluating the safety and efficacy of two doses of TAK-003 in the prevention of laboratory-confirmed symptomatic dengue fever of any severity and due to any of the four dengue virus serotypes in children and adolescents.1 Study participants were randomly assigned to receive either TAK-003, 0.5 mL or placebo, by subcutaneous injection on Day 1 and Day 90.1 The study is comprised of three parts. The current analysis, Part 1, evaluated vaccine efficacy (VE) and safety through 15 months after the first dose. Part 2 continues for an additional six months to complete the assessment of the secondary endpoints of VE by serotype, baseline serostatus and severity. Part 3 evaluates VE and long-term safety by following participants for an additional three years.1 The Part 1 and Part 2 data will form the basis for filing for licensure. The trial is taking place at sites in dengue-endemic areas in Latin America (Brazil, Colombia, Panama, Dominican Republic and Nicaragua) and Asia (Philippines, Thailand and Sri Lanka) where there are unmet needs in dengue prevention and where severe dengue is a leading cause of serious illness and death among children.1 Baseline blood samples were collected from all individuals participating in the trial to allow for evaluation of safety and efficacy based on serostatus. Company and an independent Data Monitoring Committee of experts are actively monitoring safety on an ongoing basis. Company's tetravalent dengue vaccine candidate (TAK-003) is based on a live-attenuated dengue serotype 2 virus, which provides the genetic “backbone” for all four vaccine viruses.2 Phase 1 and 2 data in children and adolescents showed that TAK-003 induced immune responses against all four dengue serotypes, in both seropositive and seronegative participants, and the vaccine was found to be generally safe and well tolerated.