Rituximab may be effective in preventing debilitating symptoms of myasthenia gravis (MG), indicating its efficacy as a potential first-line treatment, according to a randomized trial.
The results showed that patients who received rituximab had fewer symptoms and needed less rescue therapy at week 16 compared to those in the placebo group. About 70% of patients in the rituximab group had a Quantitative Myasthenia Gravis (QMG) score below 5 points while receiving 10 mg of prednisolone daily or less. Only 29% of participants in the placebo group had the same results, reported Fredrik Piehl, MD, PhD, of the Karolinska University Hospital in Stockholm, Sweden, and colleagues.
“We here observed that a single infusion of 500 mg of rituximab increased probabilities to attain minimal disease manifestations despite low doses of corticosteroids in the short to medium term, which was also reflected as lower likelihood of requiring rescue treatment or hospitalization for MG exacerbation,” the study authors wrote.
The trial was recently published in JAMA Neurology.
Early treatment with rituximab at the onset of generalized MG can help to lower the likelihood that the condition will worsen or require subsequent therapy, the study team noted.
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This double-blind, placebo-controlled trial included 87 patients previously diagnosed with MG. All participants had a score on the QMG scale of 6 or higher and experienced generalized symptoms at least once in the last 12 months, excluding those with only ocular MG manifestations.
The participants were randomized 1:1 to the rituximab cohort and the placebo cohort. There were 25 patients who received a single dose of 500 mg of rituximab by intravenous infusion, while the remaining 22 individuals made up the placebo group. The mean age was 67.4 years for the intervention group and 58 years for the placebo group. Males comprised the majority of both study arms.
Regardless, the Myasthenia Gravis Activities of Daily Living and Myasthenia Gravis Quality of Life questionnaires yielded similar results for the 2 cohorts.
Individuals from the control group were more likely to need rescue treatments (36%) than those who received the rituximab infusion (4%). Both groups had similar rates of severe cardiac events, such as 1 myocardial infarction that led to cardiac arrest and 1 lethal cardiac event in the placebo and rituximab sets, respectively.
“Further studies are needed to shed light on long-term benefit-risk balance with rituximab in generalized MG as well as to define predictive markers for disease severity early in the disease course,” the researchers concluded.
Piehl F, Eriksson-Dufva A, Budzianowska A, et al. Efficacy and safety of rituximab for new-onset generalized myasthenia gravis. JAMA Neurol. Published online September 19, 2022. doi:10.1001/jamaneurol.2022.2887