Valneva and Pfizer Complete Primary Vaccination Series in Phase 3 VALOR Lyme Disease Trial

Pfizer Inc. and Valneva SE have announced the completion of the primary vaccination series for participants in the Phase 3 trial "Vaccine Against Lyme for Outdoor Recreationists" (VALOR) for their Lyme disease vaccine candidate, VLA15. Participants, who received three doses of the vaccine, will continue to be monitored for Lyme disease until the end of the 2025 Lyme disease season.

Annaliesa Anderson, Ph.D., Senior Vice President and Head of Vaccine Research and Development at Pfizer, emphasized the significance of completing the primary vaccination series, marking a crucial step towards creating a safe and effective Lyme disease vaccine. VLA15 is the leading candidate in their collaboration with Valneva, with two Phase 3 trials currently in progress.

Juan Carlos Jaramillo, M.D., Chief Medical Officer at Valneva, expressed satisfaction with the progress of the VALOR trial. He highlighted the urgent need for new Lyme disease prevention methods due to the growing burden of the disease, particularly in the United States and Europe, where it is the most common vector-borne illness. Lyme disease requires extensive healthcare intervention and can cause severe complications if untreated.

The VALOR trial, sponsored by Pfizer, is a multicenter, placebo-controlled, randomized, observer-blinded study conducted in regions with high Lyme disease prevalence across the U.S., Canada, and Europe. The trial aims to evaluate the efficacy, safety, tolerability, immunogenicity, and lot consistency of VLA15. Participants aged 5 and older were randomized into two groups to receive either VLA15 or a saline placebo across four doses, with a booster shot administered one year after the third dose.

Pending positive trial results, Pfizer plans to submit a Biologics License Application to the U.S. Food and Drug Administration and a Marketing Authorization Application to the European Medicines Agency in 2026. Thus far, VLA15 has demonstrated a favorable safety profile across all age groups and doses in clinical trials. No safety concerns have been reported by the independent Data Safety Monitoring Board for any treatment groups.

Additionally, a second Phase 3 trial focusing on the safety of VLA15 in children aged 5 to 17 is ongoing, with enrollment completed in June 2023. Pfizer and Valneva have been collaborating on the development of VLA15 since April 2020, with updates to their agreement made in June 2022.

VLA15 is currently the most advanced Lyme disease vaccine candidate in clinical development. It uses a well-established mechanism targeting the outer surface protein A (OspA) of the Borrelia burgdorferi bacteria, which causes Lyme disease. By blocking OspA, the vaccine inhibits the bacterium's ability to transfer from tick to human. The vaccine covers the six most prevalent OspA serotypes present in North America and Europe.

Lyme disease, caused by Borrelia burgdorferi and transmitted by infected Ixodes ticks, is the most common vector-borne illness in the Northern Hemisphere. Estimated cases in the U.S. are around 476,000 annually, with roughly 129,000 cases reported each year in Europe. Early symptoms, such as erythema migrans (a type of rash), fatigue, fever, headache, mild stiff neck, and muscle and joint pain, can often be overlooked or misdiagnosed. If untreated, Lyme disease can lead to more severe complications affecting the skin, joints, heart, and nervous system. The need for a vaccine is growing as the geographic spread of the disease increases.