A Japanese vaccine candidate has been proven to be highly effective in providing protection against the dengue virus regardless of previous exposure, based on ongoing clinical trials.
The vaccine candidate, TAK-003, developed by Takeda Pharmaceutical Company Limited, was found to have an overall vaccine efficacy (VE) of 73.3%, 18 months after the administration of a second dose under the second stage of a Phase 3 trial.
Takeda said the latest results of this secondary endpoint analysis, presented during the 68th Annual Meeting of the American Society of Tropical Medicine and Hygiene (ASTMH) in November 2019, were “generally consistent” with those of the primary endpoint analysis under the first stage of the Phase 3 trial conducted 12 months after the second dose.
The primary endpoint analysis, published on November 21, 2019 in the prestigious New England Journal of Medicine, established an overall VE of 80.2%, demonstrating protection against virologically-confirmed dengue (VCD) in children ages four to 16 years regardless of previous exposure to dengue.
Takeda said higher VE was recorded following detailed assessment of secondary endpoints – 90.4% on those hospitalized because of dengue and 85.9% on those with dengue hemorrhagic fever. Efficacy against severe VCD could not be determined due to an insufficient number of cases.
Efficacy was statistically similar whether individuals had a previous history of dengue (seropositive) or not (seronegative), at 76.1% and 66.2%, respectively.
By type of dengue virus, efficacy varied. The vaccine candidate was found to be 69.8% effective against dengue serotype 1, 95.1% for dengue serotype 2, and 48.9% for dengue serotype 3. There were not enough dengue serotype 4 cases to establish efficacy.
Takeda said that consistent with previous results, the TAK-003 dengue vaccine candidate was “generally well tolerated, and there have been no important safety risks observed to date.”
“The 18-month data presented at ASTMH further our understanding of the efficacy and safety of Takeda’s dengue vaccine candidate,” said Shibadas Biswal, M.D., Takeda medical director for dengue clinical development, who presented the clinical trial data at ASTMH.
“These results are encouraging, and we’re particularly pleased to see the consistency in overall efficacy as compared to our 12-month analysis, as well as the overall efficacy in seronegative participants,” he added.
Takeda said the Phase 3 trial, dubbed Tetravalent Immunization against Dengue Efficacy Study (TIDES), is ongoing and will continue to assess safety and efficacy of the vaccine candidate in study subjects for a total of four and a half years. The vaccine candidate is not yet licensed anywhere in the world.
“While additional data is needed to fully understand the profile of TAK-003, particularly against serotype 3 in seronegatives, we see its potential to address key priorities for dengue control, including protection of seronegative populations and prevention of hospitalization,” Biswal said.