~25% of Patients with MS Treated with Ocrevus Report Wearing-Off Phenomenon

Study results presented at the 2024 Annual Meeting of the Consortium of Multiple Sclerosis Centers (CMSC) revealed that nearly 25% of people with multiple sclerosis (PwMS) being treated with Ocrevus (ocrelizumab; Genentech, South San Francisco, CA) experienced a wearing-off phenomenon (ie, a return of MS-related symptoms prior to their next infusion). Ocrevus is an anti-CD20 monoclonal antibody administered by intravenous infusion every 6 months. This study highlights the need for clinicians to be aware of the various factors that may predict wearing-off in PwMS being treated with Ocrevus.

The retrospective chart review assessed the prevalence, predictive factors, and impacts of interventions on the Overvus wearing-off phenomenon in 528 PwMS (average age of 47.5 years; 72.9% women; 72.3% diagnosed with relapsing-remitting MS). Researchers reviewed records of PwMS treated with Ocrevus at a single MS subspecialty clinic to collect demographic variables, clinical characteristics, comorbidities, presence of wearing-off, timing of symptoms, specific symptoms, and interventions focused on wearing-off. Risk factors for wearing-off were assessed using logistic regression modeling.

• The wearing-off phenomenon was observed in 24.8% of the study population, most often characterized by worsening of residual focal symptoms (79.4%) and fatigue (67.2%). 
• Wearing-off commonly developed 2 to 4 weeks before the next infusion (59.5%), and more than 80% of those who developed wearing-off did so within the first 3 years of treatment. 
• Risk factors included comorbid fatigue (odds ratio [OR] 2.10; P=.001) and non-White race (OR 2.19; P=.018), and protective factors included male sex (OR 0.56; P=.026) and Hispanic ethnicity (OR 0.48; P=.029). 
• Any intervention (eg, shortening Ocrevus infusion intervals or switching therapies) improved or resolved wearing-off over 80% of the time (P<.001).

Researchers from this study are affiliated with the University of South Florida Department of Neurology.