Exploring the impact of wearing-off phenomenon in ocrelizumab-treated multiple sclerosis patients: Insights from a comprehensive study

Background: Ocrelizumab (OCR) effectively modifies the disease course in multiple sclerosis (MS) patients but may cause a preinfusion "wearing-off phenomenon" (WoP). This study explored the prevalence, timing, and severity of this phenomenon in MS patients using the OCR, as well as the associated symptoms and treatment satisfaction. Methods: We conducted a prospective multicenter study across 11 MS centers involving MS patients aged 18-70 years who had received at least two OCR doses. The study employed a questionnaire addressing demographic, clinical, and radiological data; symptom progression; and treatment satisfaction. Results: Of the 409 patients included in the study, 406 participated. A significant portion experienced varying degrees of WoP: 39.2% sometimes, 25.9% usually, and 14.3% always, with 55.9% noting symptom onset over four weeks prior to their next dose. Common symptoms included fatigue, walking difficulties, and pain. Subgroup analysis of 334 patients revealed that 78.1% of patients experienced these effects, which correlated with shorter disease durations, a longer delay between the two doses before the last dose, and a greater rate of relapse (P>0.05). Conclusion: The WoP of the OCR is prevalent and significant among MS patients and is influenced by the dosing interval, disease duration, and relapse rate. These insights underscore the need for personalized treatment schedules and more research into factors affecting MS management.