A multivalent protein subunit vaccine, VLA15 covers six serotypes that are dominant in North America and Europe.
Leveraging a proven mechanism of action, the vaccine targets the outer surface protein A (OspA) of the Lyme disease-causing bacteria, Borrelia burgdorferi.
In pre-clinical as well clinical studies, VLA15 showed robust immunogenicity and safety data.
The randomised, observer-blind, placebo-controlled Phase II trial enrolled 625 adult and paediatric subjects who are aged between five and 65 years.
Subjects will receive placebo or VLA15 at two different schedules, notably months 0, two and six; or months 0 and six.
In the trial, VLA15 is being assessed as an alum-adjuvanted formulation and will be given as intramuscular 180µg doses. This dosage was selected based on results from two previous Phase II trials.
The goal is to demonstrate the safety and immunogenicity of the vaccine, as well as assess the optimal vaccination schedule for the Phase III trial.
Pfizer and Valneva plan to conduct primary endpoint analysis for the safety and immunogenicity at the seventh month, a time when high antibody titer levels are expected.
Top-line data from the trial is anticipated in the first half of next year.
Furthermore, in a booster phase, a subset of subjects will be given a booster dose of VLA15 or placebo at month 18. These subjects will then be followed up for three more years to track antibody persistence.
Valneva chief medical officer Juan Carlos Jaramillo said: “If successful, this trial could enable the inclusion of a paediatric population in the Phase III trial.
“Lyme disease continues to be a major concern and is prevalent in children, it is therefore extremely important for us to potentially offer a vaccine that could protect both adults and children as rapidly as we can.”
Pfizer and Valneva signed a partnership agreement in April last year to jointly develop and market the VLA15 vaccine.