Valneva SE, a specialty vaccine company focused on prevention of diseases with major unmet needs, today announced positive initial results for its first Phase 2 study (VLA15-201) of Lyme disease vaccine candidate VLA15.

Borrelia burgdorferi spirochetes/CDC

VLA15 was immunogenic across all dose groups tested. Compared to Phase 1, the higher doses used in this trial elicited higher antibody responses across all serotypes. Seroconversion rates (SCR) in the highest dose ranged from 81.5% (ST1) to 95.8% (ST2). In the age group comparable to the age group investigated in Phase 1 (18-49 years), SCRs ranged from 85.6% to 97%. The immunological response in older adults, one of the main target groups for a Lyme vaccine, is particularly encouraging.

Results did not indicate that prior exposure to Lyme (sero-positivity) has an impact on immunogenicity or safety.

As part of further Phase 2 data to be released in a few months, an analysis of the functionality of the antibodies generated with VLA15 will be conducted. In close collaboration with regulatory authorities, Valneva has developed a Serum Bactericidal Antibody assay (“SBA”) for that purpose.

VLA15 was generally safe across all dose and age groups tested. No related Serious Adverse Events (SAEs) were observed with VLA15 in this study in any treatment group. Reactogenicity decreased with subsequent vaccinations.

Overall, the tolerability profile including rates of fever appeared to be comparable to other lipidated recombinant vaccines or lipid-containing formulations.

Wolfgang Bender, MD, PhD, Chief Medical Officer of Valneva commented “We are pleased to report a successful first Phase 2 trial of our vaccine candidate against Lyme disease, a severe infection which affects an increasing number of people each year. Further data from the ongoing Phase 2 trials in the coming months will support further dose and schedule decisions. We are closely working with Pfizer to advance the development of VLA15 expeditiously.”

This first Phase 2 study, conducted in the EU and US, included 572 healthy adults aged 18 to 65 years. In the main study phase, 452 subjects received one of two dose levels (either 135µg or 180µg) of VLA15 (approximately 180 subjects each) in three injections (Days 1, 29 and 57) or placebo (approximately 90 subjects). Immunogenicity was measured by determining IgG antibodies against each of the six most prevalent Outer Surface Protein A serotypes of Lyme borreliosis in the US and Europe covered by the vaccine. The endpoint readout was immunogenicity at Day 85 (one month after finalization of primary immunization).

Valneva expects to report top-line results for the second Phase 2 study, VLA15-202, in a few months. In the VLA15-202 study, identical doses to the VLA15-201 study were tested using a longer vaccination schedule (Days 1, 57 and 180).