Is Rituximab (rituximab) used in the treatment of conditions with elevated Myelin-Associated Glycoprotein (MAG) antibodies?

From the Guidelines

Rituximab is used in the treatment of conditions with elevated Myelin-Associated Glycoprotein (MAG) antibodies, particularly in anti-MAG peripheral neuropathy, as stated in the most recent guidelines from the Journal of the National Comprehensive Cancer Network : JNCCN 1. The treatment approach for patients with elevated MAG antibodies involves the use of rituximab, which works by depleting B-cells and reducing the production of pathogenic MAG antibodies.

• The typical regimen involves intravenous infusions of Rituximab at 375 mg/m² weekly for 4 weeks, though some protocols use two 1000 mg infusions separated by two weeks.
• Treatment response should be monitored over 6-12 months, as improvement can be gradual.
• Before starting treatment, patients should undergo hepatitis B screening due to the risk of reactivation.
• Premedication with acetaminophen, diphenhydramine, and sometimes corticosteroids is recommended to reduce infusion reactions.
• This treatment is particularly beneficial for patients with progressive sensory ataxia, tremor, or significant disability from their neuropathy. However, response rates vary, with approximately 30-50% of patients showing meaningful improvement, and some may require repeated treatment courses if symptoms recur after initial improvement, as noted in the guidelines from the Journal of the National Comprehensive Cancer Network : JNCCN 1. Key considerations in the management of patients with elevated MAG antibodies include the risk of IgM flare, which can be mitigated by prophylactic plasmapheresis in patients with high IgM levels, as recommended in the guidelines from the Journal of the National Comprehensive Cancer Network : JNCCN 1 and Blood 1. In addition to rituximab, other treatment options may be considered, including combination regimens such as bortezomib, dexamethasone, and rituximab, as discussed in the guidelines from the Journal of the National Comprehensive Cancer Network : JNCCN 1. Ultimately, the choice of treatment should be individualized based on the patient's specific clinical presentation, disease severity, and response to prior therapies, as emphasized in the guidelines from the European Myeloma Network 1 and Haematologica 1. It is also important to consider the potential risks and benefits of each treatment option, including the risk of neuropathy associated with bortezomib-based regimens, as noted in the guidelines from the Journal of the National Comprehensive Cancer Network : JNCCN 1 and Annals of Oncology 1.

From the Research

Use of Rituximab in Elevated MAG Antibodies

• Rituximab has been used in the treatment of conditions with elevated Myelin-Associated Glycoprotein (MAG) antibodies, as seen in several studies 2, 3, 4, 5, 6.
• The studies suggest that rituximab can be effective in improving symptoms in patients with IgM-related neuropathies, including those with anti-MAG antibodies 2, 3, 5.
• In a double-blind, placebo-controlled study, rituximab was found to improve walking ability and reduce IgM levels and anti-MAG titers in patients with anti-MAG demyelinating polyneuropathy (A-MAG-DP) 5.
• Another study compared the outcomes of patients treated with rituximab monotherapy versus immunochemotherapy, and found that immunochemotherapy may be a valid option for patients with rapidly progressive and/or severe anti-MAG neuropathy symptoms 6.
• The use of rituximab in patients with elevated MAG antibodies has been associated with improvements in neurological symptoms, including strength, sensory function, and walking ability 2, 3, 4, 5.
• However, the response to rituximab can vary, and some patients may not experience significant improvement 3, 5.
• The treatment is generally well-tolerated, but can be associated with adverse effects, particularly when used in combination with chemotherapy 6.