Rituximab in New-Onset Generalized Myasthenia Gravis: Long-Term Follow-Up of the RINOMAX Clinical Trial

Area of Science:

• Neurology
• Immunology
• Clinical Trials

Background:

• The RINOMAX trial previously showed rituximab (RTX) superiority over standard-of-care for new-onset generalized myasthenia gravis (MG) up to 12 months.
• Long-term benefit-risk data for RTX in generalized MG remain limited.

Purpose of the Study:

• To evaluate the long-term efficacy and safety of rituximab in generalized myasthenia gravis.
• To assess the impact of RTX on disease activity, treatment burden, and hospitalization rates over an extended period.

Main Methods:

• The RINOMAX trial randomized 47 participants with moderate-to-severe generalized MG to RTX or placebo.
• Swedish MG registry data were used to track hospitalizations, rescue treatments, and disease activity scores (QMG) up to 5 years.
• Comparative analysis between early RTX exposure, delayed RTX, and placebo groups was performed.

Main Results:

• Rituximab (RTX) treatment resulted in significantly lower QMG scores at 12 and 24 months compared to placebo.
• The incidence of rescue treatments was numerically lower in the RTX arm (0.09/person-year) versus placebo (0.16/person-year).
• Early RTX exposure was associated with reduced QMG scores, hospitalizations (HR 0.24), and rescue treatments compared to delayed RTX.

Conclusions:

• Rituximab demonstrates potential for a favorable long-term disease trajectory in generalized MG, with sustained low disease activity and treatment burden.
• While RTX shows benefits, the risk of severe infections associated with B cell depletion remains a significant concern.
• Further research is needed to optimize RTX use and manage potential adverse events in generalized MG patients.