Antibodies are proteins produced by the body's immune system when it detects harmful substances such as bacteria and viruses that might cause an infection.
Monoclonal antibodies are clones of a single antibody that are developed as drug therapies. They can be designed to bind to proteins on the body's normal cells, so altering the immune response. Each one recognises a specific target protein which may only exist on a single, or a few, cells types. This means that, in theory, treatments can be designed to have a very specific effect.
In MS, this means that, if antibodies can be identified that bind to cells that are involved in attacking nerve cells and causing disease activity, treatments could be developed that would only affect those cells.
Examples of monoclonal antibodies used in multiple sclerosis include:
- natalizumab (Tysabri) which binds to and disables a target on white blood cells that allows them to cross the blood brain barrier, effectively keeping cells that might attack myelin from coming into contact with the brain or spinal cord
- alemtuzumab (Lemtrada) which binds to proteins on the surface of white blood cells that are associated with causing them to attack the myelin on nerves
- ocrelizumab (Ocrevus) which binds to and destroys B-cells, which are thought to be influencing the immune attack on myelin.
The World Health Organisations standards for naming drugs means that all monoclonal antibodies have a name ending with 'mab'.
Research into these drugs suggests that they could be more effective than other forms of treatments at reducing the number of relapses. However, it has also been shown that they can have serious side effects and any treatment with a monoclonal antibody will need to include monitoring for, and treatment of, these effects.
- MAbs 2010;2(6):670-681. Full article Monoclonal antibody therapy in multiple sclerosis.
- Expert Review of Neurotherapeutics 2013;13(3):313-335. Summary Treating multiple sclerosis with monoclonal antibodies: a 2013 update.
- Medicine (Baltimore). 2018 Feb; 97(8): e9908. Full article Efficacy of alemtuzumab and natalizumab in the treatment of different stages of multiple sclerosis patients