Pfizer and Valneva’s Lyme disease vaccine PF-07307405 enters EMA review after Phase 3 VALOR showed more than 70% efficacy and no safety concerns.
Written By: Siddhi Bhadekar, M. Pharm (QA)
Reviewed By: Pharmacally Editorial Team
Pfizer and Valneva have advanced their investigational Lyme disease vaccine PF-07307405 (LB6V, formerly known as VLA15) into European regulatory review after the European Medicines Agency (EMA) validated their Marketing Authorization Application (MAA). The filing is supported by Phase 3 VALOR data showing more than 70% efficacy in preventing Lyme disease, with no safety concerns identified in the trial.
EMA Validation Opens Formal Regulatory Assessment
EMA validation confirms that the MAA is complete enough to enter the agency’s scientific assessment. It does not represent an approval or a regulatory conclusion on the vaccine’s efficacy or safety.
PF-07307405 is a six-valent outer surface protein A (OspA)-based vaccine candidate and has advanced through two pivotal Phase 3 trials. No human Lyme disease vaccine is currently approved.
The program previously received Fast Track designation from the U.S. Food and Drug Administration (FDA), reflecting the need for new preventive options against Lyme disease.
VALOR Demonstrated More Than 70% Efficacy
The Phase 3 VALOR trial (NCT05477524) was a multicenter, randomized, placebo-controlled, observer-blinded study conducted at sites in areas of high Lyme disease incidence across the United States, Canada and Europe.
The trial enrolled 9,437 participants aged five years and older. Participants were randomized 1:1 to receive PF-07307405 or saline placebo. The vaccination schedule included doses at months 0, 2 and 5-9, followed by a fourth dose approximately one year later before the subsequent Lyme disease season.
The primary pre-specified analysis showed 73.2% vaccine efficacy from 28 days after dose four. However, its 95% confidence interval was 15.8%-93.5%, leaving the lower bound below the protocol-defined threshold of greater than 20%. Fewer Lyme disease cases occurred during the study than anticipated, affecting the precision of the efficacy estimate.
A second pre-specified analysis, beginning one day after dose four, showed 74.8% efficacy, with a 95% confidence interval of 21.7%-93.9%. Because the lower bound exceeded the predefined 20% threshold, this analysis met the protocol-defined statistical criterion supporting the regulatory filing.
PF-07307405 was well tolerated, and Pfizer and Valneva reported no safety concerns in the trial.
OspA-Based Vaccine Targets Lyme Transmission in the Tick
PF-07307405 is a multivalent protein subunit vaccine that targets outer surface protein A, or OspA, expressed by Borrelia burgdorferi and related species that cause Lyme disease.
Vaccination induces antibodies against six OspA serotypes. When an infected tick feeds on a vaccinated individual, it ingests these antibodies with the blood meal. The antibodies bind to OspA on Borrelia within the tick and inhibit the bacterium’s ability to leave the tick, reducing its transmission to the human host.
The six-valent formulation covers the six most prevalent OspA serotypes expressed by Borrelia burgdorferi sensu lato in North America and Europe.
Lyme Disease Creates a Significant Prevention Need
Lyme disease is transmitted through the bite of infected Ixodes ticks and is the most common vector-borne illness in the Northern Hemisphere. Early symptoms can include erythema migrans, fatigue, fever, headache, muscle pain and joint pain.
If untreated, infection can disseminate and cause complications involving the joints, heart, nervous system and skin. Pfizer estimates that more than 100,000 people are affected by Lyme disease each year in Europe, while more than 200 million people live in areas considered at risk.
Regulatory Review Moves Forward
Annaliesa Anderson, Ph.D., Pfizer’s Senior Vice President and Chief Vaccines Officer, said the company looks forward to working with the EMA as the candidate advances through the review process. Valneva CEO Thomas Lingelbach described the MAA validation as a major milestone in advancing a potential vaccine against Lyme disease.
Pfizer and Valneva entered their collaboration and license agreement in April 2020. Under the agreement, Pfizer holds exclusive rights to manufacture and commercialize PF-07307405, subject to regulatory approval.
The EMA validation now moves PF-07307405 into formal scientific review. If approved, the vaccine could provide the first human preventive vaccination option against Lyme disease in Europe, addressing a significant unmet public health need as the geographic footprint of the disease continues to expand.
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About the Writer
Siddhi Rajendra Bhadekar (Linkedin) is an M.Pharm professional with expertise in medical and scientific writing, literature review, publication writing, and evidence synthesis, supported by four peer-reviewed publications.
She brings working knowledge of ICH-GCP, MedDRA, pharmacovigilance, ADR/AE reporting, clinical data management, and regulatory documentation.
With experience across pharmaceutical R&D, Quality Control, and Quality Assurance, she combines scientific research skills with strong attention to accuracy and detail.
Her background in manuscript development, publication planning, and scientific communication enables her to translate complex healthcare information into clear, reliable content.