Immunotherapy Linked to Lower Relapse Risk in MOGAD

SAN DIEGO — A new retrospective analysis of patients with myelin oligodendrocyte glycoprotein antibody disease (MOGAD) indicates that treatment with immunotherapy is associated with a lower risk of relapse. The authors note that many MOGAD patients never experience a relapse and it is difficult to predict which ones will.

MOGAD can cause optic neuritis, transverse myelitis, and acute disseminated encephalomyelitis (ADEM). It was first described in 2007, and the best approaches to therapy are not yet understood. The new study is at least a starting point for understanding treatment outcomes, according to Philippe Bilodeau, MD, who presented the study during a poster session at the annual meeting held by the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS).

Predicting which patients will relapse

"I think one of the biggest unanswered clinical questions in MOGAD is trying to determine who's going to go on to have relapsing MOGAD. About 30% to 40% of patients with MOGAD will never have a second attack. So one of the big questions is: How can we identify patients who would benefit from immunotherapy, and how can we identify patients who will have a more benign disease course and may not need to be started on a treatment," said Dr. Bilodeau, a neurology resident at Massachusetts General Hospital/Brigham and Women's Hospital, Boston.

The researchers analyzed data from 143 patients seen at Massachusetts General or Brigham and Women's Hospital who had presented with their first attack. Over a follow-up period of 5 years, the relapse rate was 61.8%. The researchers examined various factors, including age of onset, high MOG titer, attack type, and male sex, and found that only the latter came close to predicting relapse, though it fell short of clinical significance (hazard ratio [HR], 0.61; P = .07).

However, treatment with mycophenolate, azathioprine, intravenous immunoglobulins (IVIG), rituximab, or tocilizumab strongly predicted a lower probability of relapse (HR, 0.25; P < .0001).

The most effective treatment for relapsing MOGAD

In a separate poster, his team examined a subset of the cohort of 88 patients who were treated with mycophenolate mofetil, B-cell depletion, rituximab, or IV immunoglobulins (IVIG) during a first or second relapse, as well as an analysis of every relapse experienced by any patient during the course of their disease. "Using a negative binomial regression, we looked at the annualized relapse rates and incidence rate ratios between the different treatments. No matter how you looked at the data — even if you looked at total time on IVIG, if you looked at time on monotherapy, excluding if they were on prednisone at the same time if they were on both IVIG and rituximab, if you only consider patients that were on high dose IVIG — IVIG was by far the best treatment and rituximab was always the least effective, and mycophenolate was always between IVIG and rituximab. So I think in that cohort, we can say with some confidence that IVIG is the most effective treatment for relapsing MOGAD," said Dr. Bilodeau.

Other studies had suggested efficacy of individual treatments, but "I think what hadn't been done is taking one cohort and comparing those treatments head to head, so that's what we were trying to do," said Dr. Bilodeau.

Both studies have the usual caveats of a retrospective study and so cannot prove causality. "We need to find more covariates to make sure that there's no confounding (factor) explaining this and to make sure that there aren't other demographic or clinical factors that explain the association. But as it stands, I think at this time starting treatment with immunotherapy is the only thing that we know will reduce the risk of having a future relapse. There's a lot of further analysis that we need to do," said Dr. Bilodeau.

He said that the study also provided some preliminary insight into treatment of pediatric disease. "We have interesting data from that analysis that pediatric-onset MOGAD actually had a particularly good response to [mycophenolate], more so than in adults," he said.

"At this point, I think a rational approach if you have someone coming in with a first relapse is, you have to assess their risk tolerance. If they're a very risk-averse patient, I think it's reasonable to start them on treatment. I think it's reasonable to monitor their titer. There's some data that if they seroconvert to negative, you might be able to stop immunotherapy. If someone has established relapsing disease, and they have adult onset [disease], IVIG should be the first-line treatment. If they're pediatric onset, either [mycophenolate] or IVIG are probably good first line treatments," he said.

"A good beginning"

The studies are a good beginning to getting a better understanding of MOGAD treatment, according to Michael Cossoy, MD, who attended the poster session and was asked to comment on the study.

"It's interesting because MOG antibody-associated disease is so relatively new that we don't have a great idea yet about who needs to be treated. Should we put them on some immunosuppressive therapy or should we wait? At the moment this is a bit of a tautology. You know that if you put people on therapy from the very first event, some of those people are not going to have a second event. And some of the people are, but you've decreased the risk of them having that second (event) if your treatment is effective. So that's what they've shown, which is great. But the question is, can you predict who's going to have a second event and know who to put on treatment and not put on treatment? It's too early to know, but this is a good start," said Dr. Cossoy, assistant professor of ophthalmology at the University of Manitoba.

Dr. Bilodeau and Dr. Cossoy have no relevant financial disclosures.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

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