Experimental Lyme Vaccine Shows Promising Protection in Phase 3 trial

An experimental six-strain Lyme disease vaccine developed by Pfizer has shown over 70% efficacy in individuals aged 5 years and older. In a phase 3 trial, the vaccine achieved approximately 70–73% protection against confirmed Lyme disease after a four-dose regimen. Although it did not meet its primary statistical endpoint-partly due to fewer-than-expected cases during the study-it successfully met the goal in secondary analysis, indicating strong potential for prevention.

Fewer than anticipated Lyme disease cases were accrued over the study period, and the pre-determined statistical criterion (95% confidence interval lower bound >20) was not met in the first pre-specified analysis (primary endpoint). Given the clinically meaningful efficacy and the fact that the 95% confidence interval lower bound was above 20 in the second pre-specified analysis, Pfizer is confident in the vaccine’s potential and is planning submissions to regulatory authorities.

“Lyme disease can cause potentially serious consequences – where individuals and families face symptoms that can disrupt daily life, work, and long-term health – and there is currently no vaccine available,” said Annaliesa Anderson, Ph.D., Senior Vice President and Chief Vaccines Officer, Pfizer. “The efficacy shown in the VALOR study of more than 70% is highly encouraging and creates confidence in the vaccine’s potential to protect against this disease that can be debilitating.”

“These results bring us a step closer to our goal of delivering a much-needed vaccine to help protect against Lyme disease. We are grateful to our partner Pfizer for their strong commitment which we both share in developing this vaccine as quickly as possible”, said Thomas Lingelbach, CEO and Board member of Valneva.

Developed in collaboration between Pfizer and Valneva, the investigational 6-valent OspA-based Lyme disease vaccine is being evaluated for its efficacy, safety, tolerability, immunogenicity, and manufacturing lot consistency. The companies entered into a collaboration and license agreement in April 2020 for the co-development of PF-07307405 and for Pfizer to exclusively manufacture and commercialize PF-07307405, assuming regulatory success.

About VALOR

The VALOR trial is a multicenter, placebo-controlled, randomized, observer-blinded trial conducted at sites in areas of high incidence of Lyme disease across the U.S., Canada, and Europe.1 Trial participants aged 5 years and older were randomized 1:1 into two trial groups and received four doses of either PF-07307405 or a saline placebo – one dose administered at months 0, 2, 5-9 followed by a fourth dose one year later, shortly before the start of the following Lyme disease season (season 2).

About PF-07307405 (LB6V)

There are currently no approved human vaccines for Lyme disease, and PF-07307405 is the Lyme disease vaccine candidate which has currently advanced the furthest along the clinical development timeline, with two pivotal Phase 3 trials completed. This investigational multivalent protein subunit vaccine uses an established mechanism of action for a Lyme disease vaccine that targets the outer surface protein A (OspA) of Borrelia burgdorferi, the bacteria that cause Lyme disease. When a person is immunized with PF-07307405, their body creates antibodies against six Borrelia OspA serotypes. As the tick feeds on the vaccinated person, these antibodies are ingested by the tick as part of its blood meal. Binding of vaccine-induced antibodies to OspA on Borrelia inside the tick inhibits the bacterium’s ability to leave the tick, preventing it from being transmitted to the human host. The vaccine candidate covers the six most prevalent OspA serotypes expressed by the Borrelia burgdorferi sensu lato species in North America and Europe.

About Lyme Disease

Lyme disease is a systemic infection caused by Borrelia burgdorferi sensu lato bacteria that are transmitted to humans by the bite of infected Ixodes ticks.3 It is considered the most common vector-borne illness in the Northern Hemisphere.4,5 The Centers for Disease Control and Prevention (CDC) has estimated that approximately 476,000 people in the U.S. are diagnosed and treated each year and 132,000 cases are reported annually in Europe from countries with surveillance systems.6 Early symptoms of Lyme disease (such as a gradually expanding erythematous rash called erythema migrans or other nonspecific symptoms like fatigue, fever, headache, mild stiff neck, muscle and joint pains) are often overlooked or misinterpreted. Left untreated, the disease can disseminate and cause more serious chronic complications affecting the skin, joints (arthritis), the heart (carditis) or the nervous system.6,7 The medical need for vaccination against Lyme disease is steadily increasing as the geographic footprint of the disease widens.