Large study finds IL-6 blockers reduce relapses in rare autoimmune nerve disease

An international study led by Mayo Clinic researchers has identified interleukin-6 (IL-6) receptor blockers as a promising option for preventing relapses in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). The study, published in JAMA Neurology, evaluated 116 patients treated with IL-6 receptor blockers across multiple centers in North and South America, making it the largest observational study of its kind for this rare condition.

MOGAD is a rare autoimmune neurological disorder in which the immune system mistakenly attacks myelin, the protective coating surrounding nerve fibers in the brain, spinal cord, and optic nerves. The disease can cause vision loss, paralysis, and other serious neurological complications. In some patients, repeated inflammatory attacks, or relapses, lead to accumulating neurological disability.

Currently, there are no treatments approved specifically to prevent relapses in MOGAD, and several therapies are used off-label. The study focused on two medications, tocilizumab and satralizumab, that belong to a class of drugs known as IL-6 receptor blockers. Researchers believe the immune signaling protein IL-6 plays an important role in the inflammation that damages myelin in people with MOGAD.

Most participants in the study received tocilizumab, which is widely available around the world, while a smaller number received satralizumab. The study found that patients had substantially fewer relapses after starting treatment and that the medications had a generally favorable safety profile, though infections remain an important consideration for clinicians.

Because MOGAD is uncommon, individual medical centers often care for relatively small numbers of patients, making it difficult to study new treatments. This multinational collaboration allowed researchers to evaluate outcomes across various patient populations while expanding the evidence for IL-6 receptor blockade in MOGAD.

"Rare diseases require collaboration," says Andreu Vilaseca Jolonch, M.D., first author of the study and a neurology fellow at Mayo Clinic. "By bringing together patients and researchers across multiple countries, we were able to generate stronger evidence than any single center could produce alone."

Multiple clinical trials evaluating treatments for MOGAD are underway. Observational studies such as this one provide important evidence while physicians await those results. "There is growing optimism for patients with MOGAD," says Eoin Flanagan, M.B., B.Ch., a neurologist at Mayo Clinic and senior author of the study. "New treatments are emerging, and we're trying to bring the best treatment options to patients while continuing to learn which therapies work best."