Pfizer Inc. and Valneva SE announced that the European Medicines Agency (EMA) has validated the Marketing Authorization Application (MAA) for PF-07307405, their investigational 6-valent OspA-based Lyme disease vaccine candidate. The validation marks the beginning of the EMA’s formal assessment of the application, which is based on results from the Phase 3 VALOR clinical trial.
Phase 3 Trial Results Support Application
The Phase 3 VALOR trial, titled “Vaccine Against Lyme for Outdoor Recreationists,” evaluated the efficacy, safety, and tolerability of PF-07307405 in 9,437 participants aged five years and older across sites in the U.S., Canada, and Europe. The trial demonstrated more than 70% efficacy in preventing confirmed Lyme disease cases, with no significant safety concerns reported during the study period.
Participants received four doses of either the vaccine candidate or a saline placebo at months 0, 2, 5 to 9, and again one year later before the next Lyme disease season. This study was multicenter, randomized, observer-blinded, and placebo-controlled, representing one of the largest studies conducted to date for a Lyme disease vaccine.
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Annaliesa Anderson, Ph.D., Senior Vice President and Chief Vaccines Officer at Pfizer, stated, “I’m proud of the progress we have made with our Lyme disease vaccine candidate and excited about the opportunity to potentially bring the first vaccine of its kind to Europe.” She emphasized that Lyme disease affects over 100,000 people annually in Europe and can lead to serious complications involving the skin, joints, nervous system, and heart if left untreated.
Vaccine Mechanism and Development History
PF-07307405 targets the outer surface protein A (OspA) of Borrelia burgdorferi, the bacteria responsible for Lyme disease. By inducing antibodies against six prevalent OspA serotypes, the vaccine aims to prevent transmission when an infected tick feeds on a vaccinated individual. The antibodies are ingested by the tick during its blood meal, inhibiting the bacteria’s ability to leave the tick and enter the human host.
Thomas Lingelbach, CEO and Board member of Valneva, noted, “We would like to thank and congratulate our partner Pfizer for the significant progress achieved towards delivering a potential vaccine solution in the fight against Lyme disease.” He highlighted that more than 200 million people live in Lyme disease risk areas across Europe, emphasizing the potential public health impact of the vaccine.
Lyme disease, transmitted through the bite of infected Ixodes ticks, is the most common vector-borne illness in the Northern Hemisphere. The U.S. CDC estimates approximately 476,000 cases are diagnosed and treated annually in the United States, while 132,000 cases are reported each year in Europe from countries with established surveillance systems. Early symptoms, including erythema migrans rash, fatigue, fever, and joint pain, are often mistaken for less serious conditions, delaying diagnosis and treatment.
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During the trial, researchers monitored for breakthrough infections occurring at least 14 days after the third dose, capturing exposure windows aligned with peak tick activity seasons. Secondary endpoints included safety assessments covering local and systemic reactions, serious adverse events, and laboratory abnormalities. Blood samples were collected periodically to evaluate immunogenicity responses across the six targeted OspA serotypes.
Pfizer and Valneva Collaboration Details
The investigational 6-valent OspA-based Lyme disease vaccine was developed through a partnership between Pfizer and Valneva, with the companies entering into a collaboration and license agreement in April 2020. Under the agreement, both companies co-develop PF-07307405, with Pfizer assuming exclusive responsibility for manufacturing and commercialization, pending regulatory approval.
Regulatory Outlook and Market Potential
Beyond Europe, Pfizer and Valneva have indicated plans to pursue regulatory submissions in other jurisdictions pending further discussions with health authorities. Additional data from ongoing or planned studies may inform potential label expansions if broader age groups or risk populations are evaluated.
