French speciality vaccine company Valneva has announced initial positive results from its second phase II study of its Lyme disease vaccine candidate VLA15.

Lyme disease is a systemic infection caused by the Borrelia bacteria transmitted to humans by infected ticks.

Valneva’s vaccine candidate targets the outer surface protein A (OspA) of Borrelia, an established mechanism of action for a Lyme disease vaccine.

The study, VLA15-202, investigated a vaccination schedule of month 0,2,6 based on matching doses.

According to Valneva, the shot was generally safe across all doses and age groups tested, with the tolerability profile including fever rates being comparable to other lapidated recombinant vaccines or lipid containing formulations.

Compared to a previous study of VLA15, immunogenicity was further enhanced using the month 0,2,6 schedule, said Valneva.

Seroconversion rates after completion of the primary vaccinations showed similar responses and ranged from 93.8% to 98.8%. In addition, antibody responses were comparable in the two dose groups tested.

Valneva also carried out a Serum Bactericidal Assay (SBA), assessing the functional immune response against Lyme disease after vaccination with VLA15. This demonstrated functionality of antibodies against all OspA serotypes.

“We are extremely pleased with these results which showed an excellent immunological profile, further supported by additional positive data through the Serum Bactericidal Assay (SBA),” said Juan Carlos Jaramillo, chief medical officer of Valneva.

“With these encouraging data we are now well positioned to continue development. Lyme disease continues to be a high unmet medical need and our objective remains to work closely with Pfizer to offer a preventative solution as soon as possible,” he added.

Valneva and Pfizer announced a collaboration for VLA15’s development and commercialisation at the end of April 2020. The two companies are working closely together on the next development steps.