The only Lyme disease vaccine candidate builds on positive Phase 2 studies and enters a final Phase 2 study VLA15-221 to include both adult and children (age 5-17 years) in new simplified dose regimens.
French specialty vaccine company, Valneva, and Pfizer Inc co-develop VLA15(2) to tackle the most common vector borne disease in the Northern Hemisphere affecting adults and children. According to the U.S. Centers for Disease Control and Prevention (CDC), every year 476,000 Americans and 200,000 Europeans are diagnosed and treated for Lyme disease.
Lyme disease is transmitted to humans through a tick bite. Lyme disease is often overlooked with typical symptoms of fever, headache, fatigue, and a skin rash that can be treated with antibiotics. If untreated, it can progress to serious inflammation affecting the joints (arthritis), the heart, and the nervous system.
The VLA15-221 study is a randomized, observer-blind, placebo-controlled Phase 2 study to enroll approximately 600 healthy participants (aged 5-65 years) who will receive VLA15 or placebo. This final Phase 2 study compares the three-dose vaccination schedule (Month 0-2-6) with a two-dose schedule (Month 0-6). By Month 7, peak antibody immune response is expected for the Primary Endpoint analysis which is the main parameter used to compare the results in different arms of the clinical trial, along with the safety readout. In Month 18, a subset of participants will receive a booster dose of VLA15 or placebo and will be monitored for antibody persistence for three years.
According to the VLA15 study, this investigational multivalent protein subunit vaccine targets the outer surface protein A (OspA) of Borrelia, an established mechanism of action for a Lyme disease vaccine. OspA is one of the most dominant surface proteins expressed by the bacteria when present in a tick.
The FDA granted Fast Track designation to the VLA15 program in July 2017. So far, VLA15 shows strong safety profile and immunogenicity in pre-clinical and clinical studies.
Valneva and Pfizer are currently preparing for a potential Phase 3 start to include a pediatric population, and if successful this will be the first vaccine to prevent Lyme disease in adults and children.