WORLD – Valneva, a specialty vaccine company for infectious diseases, and Pfizer, have completed their recruitment for the phase 2 trials, VLA15-221, of Lyme disease vaccine candidate, VLA15.

The trial builds on previous positive Phase 2 trials and includes both adult and pediatric participants with the aim to support acceleration of the vaccine candidate’s pediatric program. 

Under the recruitment program, a total of 625 participants, 5 to 65 years of age, have been randomized in the Phase 2 trial to receive VLA15 at Month 0-2-6 or Month 0-6.

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.

Vaccinees receive VLA15 at a dose of 180µg, which was selected based on data generated in the two previous Phase 2 studies.

The main safety and immunogenicity readout (Primary Endpoint analysis) will be performed at Month 7, when peak antibody titers are anticipated.

A subset of participants will receive a booster dose of VLA15 or placebo at Month 18 (Booster Phase) and will be followed for three additional years to monitor antibody persistence.

VLA15 is the only active Lyme disease vaccine candidate in clinical development today, and covers six serotypes that are prevalent in North America and Europe.

This investigational multivalent protein subunit vaccine uses an established mechanism of action for a Lyme disease vaccine that targets the outer surface protein A (OspA) of Borrelia burgdorferi, the bacteria that cause Lyme disease.

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.

The program was granted Fast Track designation by the U.S. Food and Drug Administration (FDA) in July 2017.

About Lyme Disease

According to CDC, Lyme disease is a common vector-borne disease in the United States that is primarily caused by Borrelia burgdorferi and on rare occasions by the bacteria Borrelia mayonii.

The disease is also common in Europe and Asia where it is primarily caused by B. afzelii, B. burgdorferi, and B. garinii and has its onset during summer and early fall.

Onset of Lyme disease usually takes a window period of between 3- 30 days after the tick bite as the signs and symptoms usually manifest within three stages that include early localized, early disseminated and late stage.

The early- localized stage comes with the Erythema migran as the first sign of the disease and is usually evident in about 75% of patients who report with Lyme-like symptoms.

Early-disseminated stage usually manifests a number of signs and symptoms and is usually a few days or weeks after the appearance of the Erythema migran.

After the onset of the bacterial spread through the body, patients develop indurated lesions throughout their body. Patients further develop headaches, stiff necks, fatigue, fever, and musculoskeletal aches. All these can be classified into neurologic and myocardial abnormalities.

Pfizer and Valneva are hopeful that its vaccine candidate will tap into a Lyme disease therapy market projected to reach US$ 3 Bn by 2031, at a CAGR of ~6% from 2021 to 2031, this is data according to Transparency market research.

Prior to this new vaccine candidate, a vaccine Lymerix was discontinued by the manufacturer in 2002 due to insufficient consumer demand.