Pfizer-Partnered Lyme Disease Vaccine on Track for Phase III

Specialty vaccine company Valneva, along with Pfizer, have reported positive Phase II data from their clinical trial evaluating a Lyme Disease (LD) vaccine candidate. The vaccine, VLA15, is a hopeful candidate in the prevention of this disease, which is the most common vector-borne illness spread by ticks.

Lyme Disease is caused by the bacterium Borrelia burgdorferi and is contracted via the bite of deer ticks. Early on, symptoms can include fever, headache, fatigue and joint and muscular pain. If left untreated, LD can have dire consequences. The infection spreads throughout the body, potentially causing cardiac or nervous system complications that can become difficult to treat or cause permanent damage. The current treatment for LD is often a month-long regimen of antibiotics, which is useful when the disease is caught early on. The tell-tale sign of LD is a bull’s eye rash, called erythema migrans, although some patients may never have a rash at all, making early detection and treatment difficult.

The U.S. Environmental Protection Agency reports that climate change may be a driver in the recent increased number of Lyme disease cases due to rising temperatures, allowing deer ticks to thrive where they once were unable to. The increasing number of cases has augmented the need for better protective measures. Adding to the need for better protection are instances of long-term consequences of LD even after successful treatment that, while the Centers for Disease and Control and Prevention does not currently track, several studies have reported on.

Valneva and Pfizer’s Phase II trial compared the immunogenicity of VLA15 after the administration of two or three primary series doses in groups aged 5–11, 12–17, and 18–65 years. VLA15 was immunogenic with both vaccination schedules tested, consistent with the strong immunogenicity profile observed in this age group in previous studies. However, the companies found that the vaccine candidate was more efficient in producing antibodies against a surface protein of the LD bacterium in the three-dose regimen, supporting the use of the three-dose regimen in the planned Phase III clinical trial. The analysis also supported an acceptable safety and tolerability profile, and the companies expect to release initial pediatric data in the first half of 2022.

“I’m very pleased with these results, which are critical for determining the optimal vaccination schedule for our planned Phase III trial. In partnership with Pfizer, we are excited to further investigate this vaccine candidate, which will hopefully help provide protection against Lyme disease for both adults and children,” said Juan Carlos Jaramillo, M.D., chief medical officer of Valneva.

VLA15 is the only LD vaccine candidate that is currently in clinical development. The vaccine specifically targets the outer surface protein of the bacteria that causes LD and covers six variants of the protein that are expressed. Pfizer and Valneva entered into a collaboration agreement in April 2020 to develop the vaccine candidate and the program was granted Fast Track designation by the U.S. Food and Drug Administration. The vaccine candidate proves hopeful after a previous LD vaccination attempt, LYMErix, was pulled off the market in 2002 amidst fear of side effects and declining sales.