The study builds on previous Phase 2 studies: incorporating new dose regimens and now including children aged 5-17 years old. It will determine whether the candidate proceeds to Phase 3 studies.
Kathrin Jansen, Senior Vice President and Head of Pfizer Vaccine Research and Development, said: “We hope this Phase 2 trial, with a simplified schedule, will provide evidence that the investigational vaccine can be used in populations that are at risk of contracting Lyme disease, potentially including children age five years and older.”
Lyme disease is a systemic infection caused by Borrelia bacteria burgdorferi sensu lato transmitted to humans by infected Ixodes ticks4. It is considered the most common vector borne illness in the Northern Hemisphere. According to the U.S. Centers for Disease Control and Prevention (CDC), approximately 476,000 Americans are diagnosed and treated for Lyme disease each year with at least a further 200,000 cases in Europe.
The effects of climate change – such as warmer winters - means that ticks are spreading to new areas and the medical need for vaccination is steadily increasing, note the companies.
Valneva and Pfizer entered into a collaboration agreement in April 2020 to co-develop the multivalent protein subunit candidate VLA15. The program had previously been granted Fast Track designation by the US FDA in July 2017.
The vaccine covers six serotypes which are prevalent in North America and Europe. It 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.
VLA15 has demonstrated ‘strong immunogenicity and safety data in pre-clinical and clinical studies so far,’ note the companies.
Phase 2 study
- VLA15-221 is a randomized, observer-blind, placebo-controlled Phase 2 study. It is the first clinical study with VLA15 that enrolls a pediatric population aged 5 years and older.
- Around 600 participants will be split equally between a placebo group and two immunization schedules (Month 0-2-6 or Month 0-6, 20) or placebo (Month 0-2-6). Vaccinees will receive VLA15 at a dose of 180µg, dosage selected based on the two previous Phase 2 studies.
- The primary endpoint analysis will be at Month 7, where peak antibody titers are expected. A subset of participants will receive a booster dose of VLA15 or placebo at Month 18 (Booster Phase) and will be followed up for further 3 years to monitor antibody persistence.
- VLA15 will be tested as an alum-adjuvanted formulation and administered intramuscularly.
- The study will be conducted at sites which are located in areas where Lyme disease is endemic and will enroll volunteers with a cleared past infection with Borrelia burgdorferi, the bacteria that cause Lyme disease, as well as B. burgdorferi naïve volunteers.
Under the terms of the April 2020 agreement, Valneva is eligible to receive a total of $308m cash payments consisting of a $130m upfront payment, $35m in development milestones and $143m in early commercialization milestones (The initiation of this Phase 2 study will trigger a $10m milestone payment from Pfizer to Valneva).
Valneva is funding 30% of all development costs; and in return Pfizer will pay Valneva tiered royalties starting at 19%. Pfizer will lead late-stage development and have sole control over commercialization.
