An approved lymphoma treatment, rituximab was found to be effective and safe for relapsing-remitting multiple sclerosis (RRMS) patients whose active disease has failed to respond to immunosuppressive therapies, a retrospective French study reports.
Rituximab is an engineered antibody developed by Roche to specifically target the cell surface protein CD20 often found in immune B-cells. It is sold under the name Rituxan in the U.S. and MabThera in Europe as a treatment for certain non-Hodgkin’s lymphomas, chronic lymphocytic leukemia, and select autoimmune diseases.
Because of its potential to prevent autoimmunity, rituximab has been suggested to treat MS patients who do not respond to available disease-modifying therapies (DMTs). But its potential and safety remain unclear, with some studies providing evidence of efficacy while others fail to achieve similar results.
In this study, from a total of 15,984 RRMS patients being followed at nine clinical centers in France, researchers identified 50 patients with confirmed active disease prior to being treated with rituximab off-label. All had failed to respond to prior DMTs — including Gilenya (fingolimod), Tysabri (natalizumab), or Novantrone (mitoxantrone).
A total of 12 relapses were reported in 10 patients after starting rituximab treatment, 83 percent of which (10 relapses) occurred between the treatment’s start and a first maintenance infusion at six months. All these patients recovered and had stable disease or reported a lessening in disability during the median follow-up period of 1.1 years that the study covered.
Analysis of the annualized relapse rates (ARR) reported for these 50 patients confirmed rituximab’s efficacy in controlling disease activity. Mean ARR at disease onset and after earlier treatments were between 1 and 0.8; after receiving rituximab that significantly dropped to 0.18. Median disability scores, determined by the expanded disability status scale (EDSS), also improved from 4.5 to 4 upon rituximab treatment.
About 70 percent of these patients showed no evidence of disease activity at the last clinical evaluation. Of the 66 MRI scans performed in the first six months of treatment, 95.5 percent showed no evidence of active inflammation. Brain scans further showed that only 8 percent of the patients had active or new brain lesions after six months of using rituximab, compared to 72 percent while on DMTs.
Rituximab was found to be well-tolerated and safe overall. A total of 16 adverse events were reported, and most were mild to moderate in severity. The most common side effects were infections and reduced levels of neutrophils (a type of white blood cell).
There were no reports of progressive multifocal leukoencephalopathy (PML) — a life-threatening brain viral infection associated with some MS treatments.
According to the team, this study provides “evidence that rituximab reduces clinical and MRI disease activity in patients with active RRMS despite immunosuppressive DMT.”
Compared to currently available MS treatments, rituximab’s “cost is limited and tends to decrease with the development of biosimilars, opening new therapeutic options for low-income or middle-income countries,” the researchers added.