Ocrelizumab Wearing-Off Phenomenon: Prevalence, Predictors, and Outcomes After Intervention

Studies have suggested a wearing-off phenomenon characterized by subjective worsening of symptoms prior to subsequent infusions in more than half of people with multiple sclerosis (MS) treated with ocrelizumab. This study assesses the prevalence, characteristics, predictive factors, and impacts of different interventions on wearing off in a large cohort of people with MS receiving ocrelizumab.

Clinical records of people with MS receiving ocrelizumab were reviewed to collect demographic variables, clinical characteristics, comorbidities, presence of wearing off and its specific symptoms, and responses after interventions to wearing off. Logistic regression modeling was used to assess predictors of wearing off.

Wearing off was observed in 24.8% of 528 people with MS receiving ocrelizumab, most often characterized by worsening residual focal symptoms (79.4%) and fatigue (67.2%). Risk factors for wearing off included obesity (OR, 1.93; P = .013), fatigue (OR, 2.22; P < .001), and use of an assistive device for ambulation (OR, 2.16; P = .004). Any intervention, such as shortening ocrelizumab infusion intervals or switching therapies, improved or resolved wearing off in over 80% of participants (P < .001).

Wearing off was observed in nearly a quarter of people with MS receiving ocrelizumab. Clinicians should be aware of predictive factors for wearing off with ocrelizumab and that interventions were generally effective at mitigating this phenomenon.