Study found Ocrevus and rituximab may not slow disability progression in PPMS

A recent real-world study in France suggests that anti-CD20 therapies, like Ocrevus (ocrelizumab) and rituximab, may not effectively slow disability progression in people with primary progressive multiple sclerosis (PPMS), a form of MS that gradually worsens over time.

Both Ocrevus and rituximab are designed to target and destroy B-cells, a type of immune cell believed to contribute to MS-related neurodegeneration by producing harmful antibodies. These therapies aim to reduce the autoimmune attacks associated with MS and potentially ease symptoms or slow disease progression.

Ocrevus is currently the only approved treatment for PPMS and is also used for relapsing forms of MS. Rituximab, although not approved for MS, is often prescribed off-label for the condition due to its approval for treating certain blood cancers and autoimmune diseases.

The study analysed data collected between January 2016 and June 2021 from people who hadn’t received disease-modifying therapies for at least two years and had never been treated with anti-CD20 or long-lasting immunosuppressive therapies. Out of the 1,184 participants, 426 (36%) were treated with anti-CD20 therapies – 295 received rituximab and 131 were given Ocrevus – while 758 (64%) were untreated.

The treated group was, on average, 6.7 years younger and had a shorter disease duration compared to the untreated group. A larger portion of the treated group also had active disease in the two years before the study (54.5% vs. 27.8%).

The main objective was to compare how long it took for patients in both groups to experience confirmed disability progression (CDP), defined as an increase in their Expanded Disability Status Scale (EDSS) score that lasted at least three months. The findings, adjusted for other factors, revealed no significant difference between the treated group (3.71 years) and the untreated group (3.87 years) in terms of time to CDP. At two years, slightly more treated patients showed signs of progression (28.2% vs. 25.4%), though this difference was not statistically significant.

For patients starting treatment after Ocrevus was approved in France in 2018, no significant difference in disability progression was seen between the Ocrevus-treated and untreated groups.

Most of the treated patients in the study received rituximab, and although data on the Ocrevus-treated subgroup suggested no notable effect on progression, the small sample size (131 patients) made interpretation challenging.

Secondary outcomes, including relapse rates and MRI-detected disease activity, were also similar between the treated and untreated groups. However, the treated group experienced nearly double the rate of serious infections compared to the untreated group.

The researchers concluded that ongoing evaluation of treatment risks and benefits is necessary to determine the most effective care for people with PPMS being treated with anti-CD20 therapies.