Lyme Disease Vaccine Candidate Continues to Show Strong Immune Response Following Second Booster Dose

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Valneva and Pfizer have shared positive Phase II results from their study of VLA15, a Lyme disease vaccine candidate. The study evaluated a second booster dose given one year after a first booster dose. VLA15’s immune response and safety profile one month after receiving the second booster dose were in line with those reported after receiving the first booster dose.¹

Additionally, results showed a significant anamnestic antibody response across the six serotypes covered by VLA15 in pediatric (5 to 11 years of age), adolescent (12 to 17 years of age), and adult (18 to 65 years of age) participants. Seroconversion rates were above 90% for all outer surface protein A serotypes across the age groups, which is in line with rates following the first booster.

The Phase II study, VLA15-221 (NCT04801420), is a randomized, observer-blind, placebo-controlled trial. The 560 healthy participants received VLA15 in one of two immunization schedules or placebo. Immunogenicity, the study’s primary endpoint, was evaluated one month after completion of the primary series vaccination schedule. Eligible participants will be followed for an additional year to monitor antibody persistence.

“Personal preventive behaviors are currently the only recommended strategies to help protect yourself from Lyme disease. These data from the VLA15-221 study are an important step towards a potential vaccine that could help prevent the disease and ease the burden of acute, severe and sometimes persistent consequences,” Annaliesa Anderson, PhD, senior vice president and head vaccine research and development at Pfizer said in a press release. “Together with our partner Valneva, we look forward to progressing our vaccine candidate in the ongoing Phase III clinical trials.”

Earlier in July, Valneva and Pfizer announced participants in a Phase III trial of VLA15 had completed the primary vaccination series of three doses. In this study, participants aged 5 years and older were randomized 1:1 into two groups and will receive four doses of either VLA15 or a saline placebo. Doses are given at months 0, 2, 5-9, and then an additional booster dose one year after the third dose.²

This Phase III trial of VL15, VALOR (NCT05477524), is a multicenter, placebo-controlled, randomized, observer-blinded study. It is being conducted at sites across the United States, Canada, and Europe in areas where Lyme disease is highly endemic.

In a press release from the time, Anderson said, “The completion of the primary series of our VALOR trial is a critical step toward our goal of providing a safe and effective vaccine against Lyme disease. VLA15, the Lyme disease vaccine candidate we are co-developing with Valneva, is the one which has advanced the furthest along the clinical development timeline, with two Phase III trials in progress.”

Juan Carlos Jaramillo, MD, chief medical officer, Valneva, added, “We are pleased to see the progress of our Phase III VALOR trial. Lyme disease is the most prevalent vector-borne disease in the United States and Europe. It can result in debilitating complications and extensive healthcare treatments. Given the growing burden, high medical need, and lack of effectiveness with current interventions, there is an urgent need for novel approaches to help prevent Lyme disease.”

If results of the Phase III VALOR study are positive, Pfizer plans on submitting a Biologics License Application (BLA) to the FDA and a Marketing Authorization Application (MAA) to the EMA in 2026.

References

1. Valneva and Pfizer Report Further Positive Phase 2 Booster Results for Lyme Disease Vaccine Candidate. News release. Valneva. September 3, 2024. Accessed September 3, 2024. https://valneva.com/press-release/valneva-and-pfizer-report-further-positive-phase-2-booster-results-for-lyme-disease-vaccine-candidate/

2. Phase 3 VALOR Lyme Disease Trial: Valneva and Pfizer Announce Primary Vaccination Series Completion. News release. Valneva. July 17, 2024. Accessed September 3, 2024. https://valneva.com/press-release/valneva-and-pfizer-report-further-positive-phase-2-booster-results-for-lyme-disease-vaccine-candidate/