A drug that weakens the immune system is showing big promise as potentially the first treatment option for multiple sclerosis (MS). In three large-scale, multi-center clinical trials, the drug ocrelizumab was shown to be effective against both types of multiple sclerosis, the progressive form and the relapsing remitting form.
"It's very significant because this is the first time a phase three trial has been positive in primary progressive MS,” said Gavin Giovannoni, professor at the Barts and The London School of Medicine and Dentistry, and co-author of the study, published in the New England Journal of Medicine.
Multiple sclerosis is described as a demyelinating disease whereby the body’s immune system mistakenly attacks the myelin sheath covers in the brain and spinal cord. This disrupts the electrical signal traveling from the brain to the body, and leads to physical and neurologic disabilities. The progressive form of MS causes patients to slowly deteriorate over time, while the relapsing form causes patients to go through bouts of symptoms and recovery. There is no cure for either form of MS.
To combat a rogue immune system, researchers focused on a drug that can quell the assault on the myelin sheath. Indeed, ocrelizumab, patented by Hoffman-La Roche, prevents the B cells from attacking the protective myelin covers.
Tested in patients with both forms of MS, the drug seems to stop the inflammation process in the brain. This results in less fatigue and muscle weakness. Vision seems to also be improved. Furthermore, scans show significantly less brain loss with the help of ocrelizumab.
"The results shown by these studies have the potential to change how we approach treating both relapsing and primary progressive MS,” said Giovannoni.
The drug is under evaluation from both the European Medicines Agency and the U.S. FDA.
Despite the big promises for MS, researchers are cautiously optimistic as a drug that dampens the immune system could incur other health troubles, such as infection and cancer. As such, they are rigorously testing for side effects associated with the drug.
"This is the first drug to show a significant effect in slowing disability progression in a phase three trial in primary progressive multiple sclerosis and therefore represents a landmark study in the field,” said Peter Calabresi, professor of Neurology from Johns Hopkins University who was not associated with the study.
Additional sources: BBC