Vatelizumab (GBR 500) is an investigational immunomodulatory drug (one that changes the activity of the immune system) developed by Glenmark Pharmaceuticals for the treatment of multiple sclerosis (MS).
How vatelizumab works
MS symptoms are caused by the immune system mistakenly targeting the myelin sheath (a protective layer that surrounds nerve fibers) in the brain and spinal cord. Immune cells (or lymphocytes) are directed to the nervous system and cause inflammation and eventual permanent nerve damage.
Vatelizumab is a monoclonal antibody (a protein designed to interact with a specific target) that targets VLA-2 (or alpha2-beta1 integrin). VLA-2 is a collagen-binding molecule expressed on activated lymphocytes. It has many potential roles in the immune system. VLA-2 is involved in cell adhesion and the process of moving lymphocytes to a target tissue, such as the brain and spinal cord. It also may be involved in the regulation of T-cells, a type of lymphocytes that can trigger inflammation.
Vatelizumab’s mechanism of action is not known, but it is believed that it blocks the VLA-2 integrin on activated immune cells, leading to an interference with collagen-binding at the site of inflammation, preventing them from entering the brain and spinal cord and thus stopping them from attacking and damaging myelin, therefore, reducing the inflammatory cascade in MS process.
In a mouse model of MS, treatment with an antibody against VLA-2 suppressed inflammation in the brain and spinal cord when given early in the disease.
Vatelizumab in clinical trials
In 2011, vatelizumab was licensed to Sanofi, to be further developed and assessed. Genzyme, a Sanofi company, initiated a Phase 2 clinical trial (NCT02222948) called EMPIRE, with the intent to assess the safety and effectiveness of vatelizumab in patients with relapsing remitting MS (RRMS), followed by an open label extension study (NCT02306811) for long-term safety analysis.
However, following the results of a pre-planned interim analysis that revealed that the primary effectiveness outcome was not met, Sanofi decided to discontinue the development of vatelizumab in 2015. As this decision was not due to safety concerns, Glenmark intends to continue the development of vatelizumab once it is returned from Sanofi. The contract with Sanofi was terminated early in 2017, but no further announcements have been made since.
The EMPIRE trial, originally due to be completed in 2017, was terminated in 2016 alongside the open label extension study.