Rituximab treatment stabilizes disability in SPMS patients: Analysis
Off-label use of antibody therapy over 2 years also found to reduce relapses
Treatment with rituximab, a CD20 inhibitor used off-label for multiple sclerosis (MS) patients, can stabilize disability progression and reduce disease activity in people with secondary progressive MS (SPMS), according to a review of several published studies.
These benefits were reported over a mean follow-up of two years, and were particularly more prominent in patients with shorter disease duration and those with higher disability levels before starting the treatment.
Based on their findings, the researchers suggested that longer-term treatment with rituximab might be helpful for patients in the later stages of MS.
“Considering the observed benefits, continuation of [rituximab] treatment in MS patients upon reaching the progressive phase could be a viable option, particularly for those with active disease,” the team wrote.
The study, “Rituximab in secondary progressive multiple sclerosis: a meta-analysis,” was published in Annals of Clinical and Translational Neurology.
Researchers analyze 13 studies to find effects of rituximab treatment
Most people with multiple sclerosis are initially diagnosed with relapsing-remitting MS, or RRMS — a form of the disease marked by periods of new or worsening neurological symptoms (relapses), followed by periods of total or partial recovery (remissions). As the disease progresses, many of these patients will transition to a progressive form of MS known as SPMS, in which symptoms get progressively worse with time, independently of relapses.
While seen as different disease entities, “evidence indicates that RRMS and SPMS may not have clear boundaries,” the researchers wrote. Thus, per the team, some treatments may be similarly effective in both disease forms.
Rituximab (marketed as Rituxan and others) is an antibody-based therapy sometimes used off-label in people with RRMS. It targets the CD20 receptor at the surface of B-cells, leading to their death and easing inflammation. However, “data on its impact on SPMS disability progression are limited,” the researchers wrote.
To know more about rituximab’s effectiveness in SPMS, the team of researchers, from Thailand, examined data from 13 previously published studies that had assessed the outcomes of SPMS patients given at least one infusion of the medication, which is approved as a cancer treatment.
A total of 604 patients, mostly female (65.7%), were included in the analysis. They had a mean age of 44.6 and had been living with MS for an average of 14.2 years at the time they started rituximab. In most cases, treatment was given as an initial dose of 1,000 mg two weeks apart, followed by 500 to 1,000 mg doses administered every 6-9 months.
The results showed that, after about two years of treatment, there were no significant changes in the patients’ mean disability levels, as assessed with the Expanded Disability Status Scale (EDSS).
“This suggests a potential benefit of [rituximab] in stabilizing disability progression in SPMS,” the researchers wrote.
Patients with worse disability at treatment start see greatest benefits
The stabilization in disability levels was particularly evident in patients with relatively high levels at the treatment’s start — those with EDSS scores higher than 5 — and in patients with a disease duration shorter than 10 years. Age at treatment initiation did not influence the outcomes.
Data on annualized relapse rate — the average number of relapses over one year — was available for 245 patients across seven studies. These results indicated that rituximab significantly reduced the number of relapses per year by 0.74.
Two studies assessed the proportion of patients with confirmed disability progression over two years, which essentially is an increase in EDSS levels that’s confirmed in a subsequent doctor’s visit. One study demonstrated that MS disability worsened in a third of the patients, while improving in slightly more than a quarter (26.6%). In another study, the proportion of patients with confirmed disability worsening was 12.5% in the rituximab group, compared with 25% in the control group.
Rituximab demonstrates a clear ability to reduce relapse frequency and shows promise in stabilizing disability progression … while maintaining a favorable safety profile.
Finally, among the two studies with MRI data before and after treatment, the proportion of patients with inflammatory lesions decreased by more than 50%.
Adverse events associated with rituximab were experienced by 20.7% of patients. The most common included infections and infusion-related reactions.
“Rituximab demonstrates a clear ability to reduce relapse frequency and shows promise in stabilizing disability progression over the medium term (2 years) while maintaining a favorable safety profile,” the researchers wrote.
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