Valneva and Pfizer announced further positive Phase 2 results, including booster response, for Lyme disease vaccine candidate VLA15.
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The Phase 2 study, VLA15-202, is evaluating the immunogenicity and safety of VLA15 in a Month 0-2-6 vaccination schedule.
The study enrolled 246 healthy adults 18 to 65 years of age in the U.S. As announced in October 20201, the study met its primary endpoint of demonstrating that VLA15 was immunogenic across all dose groups tested and elicited high antibody responses across all serotypes (ST1 - ST6) at one month after completion of the primary vaccination series. Continued evaluation at Month 18 showed that antibody titers declined thereafter across all groups, remaining above baseline but confirming the need for a booster strategy.
VLA15 was safe and well-tolerated across all doses and age groups tested. No related Serious Adverse Events (SAEs) were observed in any treatment group.
Participants who received a complete primary vaccination series with 180 µg doses of VLA15, were invited to continue the study in a booster extension phase and were randomized to receive an additional 180 µg dose of VLA15 (N=39) or placebo (N=19) at Month 18.
VLA15’s acceptable safety profile was confirmed through one-month post-booster. Administration of a booster dose elicited a strong anamnestic response yielding a 2.9-fold (ST3) to 4.2-fold (ST1, ST4) increase (Geometric Mean Fold Rise) in anti-OspA IgG antibody titers compared with titers observed after primary immunization.
All participants seroconverted to anti-OspA IgG after the booster dose, meaning Seroconversion Rates (SCRs) were 100% for all OspA serotypes.
SCR was defined as the rate of subjects that changed from seronegative at baseline to seropositive. Additionally, subjects who were seropositive at baseline needed to show at least a 4-fold increase in anti-OspA IgG compared to baseline titer. Functionality of elicited antibodies was demonstrated by Serum Bactericidal activity Assays, leading to SCRs ranging from 86.8% (ST2) to 100.0% (ST3) after the booster. The study is continuing to monitor persistence of antibody responses.
Pfizer and BioNTech announced they have submitted data to the U.S. Food and Drug Administration (FDA) from the Phase 2/3 trial of their COVID-19 vaccine in children 5 to <12 years of age.
The Companies announced positive topline results from the pivotal trial on September 20, 2021. In the trial, which included 2,268 participants 5 to <12 years of age, the vaccine demonstrated a favorable safety profile and elicited robust neutralizing antibody responses using a two-dose regimen of 10 μg doses. These results – the first from a pivotal trial of any COVID-19 vaccine in this age group – were comparable to those recorded in a previous Pfizer-BioNTech study in people 16 to 25 years of age, who were immunized with 30 μg doses. The 10 μg dose was carefully selected as the preferred dose for safety, tolerability and immunogenicity in children 5 to <12 years of age.
These data have been shared with the FDA for the Agency’s initial review. A formal submission to request Emergency Use Authorization (EUA) of the companies’ COVID-19 vaccine in children 5 to <12 years of age is expected to follow in the coming weeks. Submissions to the European Medicines Agency (EMA) and other regulatory authorities are also planned.
Topline immunogenicity and safety readouts for the other two age cohorts from the trial – children 2 to <5 years of age and children 6 months to <2 years of age – are expected as soon as the fourth quarter of this year.
Pfizer and BioNTech plan to submit data from the full Phase 3 trial for scientific peer reviewed publication.
The Phase 1/2/3 trial initially enrolled up to 4,500 children ages 6 months to <12 years of age in the United States, Finland, Poland, and Spain from more than 90 clinical trial sites.
It was designed to evaluate the safety, tolerability, and immunogenicity of the Pfizer-BioNTech vaccine on a two-dose schedule (approximately 21 days apart) in three age groups: ages 5 to <12 years; ages 2 to <5 years; and ages 6 months to <2 years. Based on the Phase 1 dose-escalation portion of the trial, children 5 to <12 years of age received a two-dose schedule of 10 μg each while children under age 5 received a lower 3 μg dose for each injection in the Phase 2/3 study. The trial enrolled children with or without prior evidence of SARS-CoV-2 infection. ■