Zeroing in on CIDP

A trial at The Neuro hopes a precision therapy can reduce the auto-immune response that drives this rare inflammatory disease

 April 8, 2026 || by Sophie Lorenzo

Autoimmune conditions can be particularly challenging to treat. Doctors need to be able to dial down the immune system’s overreaction when it mistakes an individual’s own cells for external invaders and begins to attack them. But current standard of care treatments can block the immune system too well – eventually repressing it so much that it leaves individuals vulnerable to infection and causes other long-term side effects.

A precision strike

What doctors need is something much more precise, targeting the part of the immune response that is directly causing issues. That’s what a clinical trial at The Neuro (Montreal Neurological Institute-Hospital) hopes to do for Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), a rare inflammatory condition where part of the body’s immune system attacks the myelin sheaths that protect peripheral nerves.

“This study is very exciting,” says Rami Massie, MD, a neurologist specializing in neuromuscular conditions and the principal investigator for the study at The Neuro’s Clinical Research Unit. “In the phase 2 clinical trial for this treatment, participants with CIDP responded well, including some whose condition had been resistant to standard of care. The results were promising.”

According to CIDP Canada, people who develop this condition experience tingling, burning, numbness, and muscle weakness in the arms and legs making activities such as walking very difficult. They can also suffer from fatigue, loss of balance and reduced reflexes, greatly disrupting daily life. People of all ages and genders can develop CIDP, but it is more common in men, and occurs more frequently over the age of 50.

Foiling the complement

The trial will evaluate whether a potential new treatment can block the immune response that causes the symptoms of CIDP by targeting the complement system — a group of proteins that act as your body’s first line of defense, reacting immediately to foreign invaders like bacteria and viruses. In CIDP, part of the complement system has gone rogue: attacking first and asking questions later.

“The treatment being studied is a protein designed to act like human antibodies in the immune system and bind to a single target and block its activity. This type of approach has worked well in treating generalized Myasthenia Gravis, and we are hopeful that it will work in CIDP,” concludes Massie.

This trial is among the first to study the efficacy of a complement inhibitor to treat CIDP. The Neuro is one of only three sites in Canada with this Phase 3 clinical trial.

Interested individuals are not required to pause their standard of care therapy before participating in the trial. For more information, contact nm.neurocru@mcgill.ca, or visit cru.mcgill.ca/nm.