Pfizer Confirms Positive Date of Lyme Disease Vaccine Candidate

Pfizer and Valneva recently announced further positive results from the Phase 2 clinical trial evaluating their Lyme disease vaccine candidate, VLA15.

The trial, VLA15-221, enrolled 294 healthy adult participants to receive a 180 microgram dose of VLA15. And a subset of participants will receive a booster of the vaccine or placebo during the booster phase.

VLA15-221 compared the immunogenicity of VLA15 after a two- or three-dose primary series at Month 0-6 or Month 0-2-6, respectively, in three groups of participants aged five to 11, 12 to 17, and 18 to 65 years of age.

The trial aimed to show safety and immunogenicity down to five years of age and evaluate the optimal vaccination schedule for use in a Phase 3 trial. This study is the first with VLA15 that enrolled a pediatric population. And the vaccine was found to be immunogenetic for both primary doses. 

The trial data is consistent with the strong immunogenicity profile observed in previous Phase 2 studies. But the induction of anti-OspA IgG antibody titers was higher in participants who received the three-dose primary series than those who received the two-dose primary series.

Therefore, the planned Phase 3 trial will leverage the three-dose primary series, which will assess the safety and immunogenicity of VLA15 in patients five to 18 years of age. Initial pediatric data are expected in the first half of 2022.

“Lyme disease is increasingly impacting people throughout the northern hemisphere, potentially due to environmental changes and more active outdoor lifestyles,” Kathrin U. Jansen, PhD, senior vice president and head of vaccine research and development at Pfizer, said in the announcement.

“The continued positive data from the VLA15-221 trial support the ongoing development of this vaccine candidate, and we look forward to continuing to work with Valneva to potentially help protect people against Lyme disease,” Jansen continued.

VLA15 is currently the only Lyme disease vaccine candidate in clinical development. The multivalent protein subunit vaccine uses an established mechanism of action for a Lyme disease vaccine that targets the outer surface protein A (OspA) of the bacteria that cause Lyme disease.

In July 2017, FDA granted VLA15 Fast Track designation.

The program is currently the only active Lyme disease vaccine program in clinical development and covers six serotypes prevalent in North America and Europe. And in July 2021, Pfizer and Valneva completed recruitment for the Phase 2 clinical trial of the vaccine.