"If we can mitigate (the side effects) of the treatments we have, we'll be finally close to a cure," Dr. Alexandre Prat said.
A team of researchers at the Université de Montréal has identified a potential drug target that could safely slow down the progression of multiple sclerosis, a debilitating disease of the central nervous system that has afflicted more than 77,000 Canadians.
MS is an autoimmune disorder, meaning a person’s own immune cells somehow invade the central nervous system. Normally, a certain type of immune cell, known as the B cell, is responsible for fighting infection and protecting against cancer.
But in people suffering from MS, those B cells cross the blood-brain barrier and cause damage to brain tissue. The U de M researchers discovered that people with MS have B cells that overproduce a molecule that makes it easy for those cells to cross the blood-brain barrier.
The researchers then found a way to block that molecule, called ALCAM, in lab mice. The results of their study were published Wednesday in the journal Science Translational Medicine.
“By blocking this molecule in mice, we were able to reduce the flow of B cells into their brains and, as a result, slow the progression of the disease,” said Dr. Alexandre Prat, a neuroscientist at the Centre de recherche du CHUM, and one of the authors of the study.
Currently, there are more than a dozen therapies for MS, including what are called B-cell depletion therapies. However, one of the main problems with those therapies is that people with MS still need their B cells.
“Unfortunately, these therapies remove all the B cells from the (blood) circulation of the patient, and this brings severe immunosuppression, leading to the development of cancer and very severe infection,” Prat explained. “So our goal was not to remove the B cells, but to prevent them from migrating into the brain.”
At present, there is no drug that Prat is aware of that specifically targets the ALCAM molecule. Still, he predicted it could take a pharmaceutical company five to six years to develop one, and then have it tested in a clinical trial.
“In the field of MS, we’re getting very close to reaching a cure,” he added. “Several of the medications that we use currently for the treatment of MS are extremely efficient and they do control the disease quite well. The problem we’re facing is all the side effects that these medications have in terms of infection and cancer. If we can mitigate this aspect of the treatments we have, we’ll be finally close to a cure.”
Canada has one of the highest rates of MS in the world, with an estimated one in every 385 Canadians living with the disease. Symptoms can include fatigue, lack of coordination, vision problems, cognitive impairment and mood changes.