Objective:

Assessment of the effectiveness, safety and tolerability of Ocrelizumab in the treatment of patients with Relapsing Remitting Multiple Sclerosis (RRMS) and Primary Progressive Multiple Sclerosis (PPMS) in Southeastern Ontario.

Background:

Ocrelizumab demonstrated efficacy in improvement of clinical outcomes in RRMS and PPMS in 3 phase III clinical trials: ORATORIO, OPERA I and OPERA II. Overall, it was well-tolerated, with only 4.1% experiencing an adverse event that led to discontinuation of the trial agent in ORATORIO, 3.2% in OPERA I and 3.8% in OPERA II.

Design/Methods:

In this single center retrospective observational study, we analyzed the annual relapse rate, expanded disease disability scale (EDSS), MRI parameters, adverse events, and treatment discontinuation rate. The data was collected at baseline prior to starting treatment and one year follow-up.

Results:

51 patients with RRMS and 22 with PPMS were included. 67% of the patients were female. The mean EDSS at one year was unchanged compared to baseline for both RRMS (3.4) and PPMS (5.5) patients. 22.4% and 22.7% had new or enlarging T2-hyperintense lesions on MRI at one-year follow-up in RRMS and PPMS respectively, respectively.  A total of 10 patients developed a single relapse while on ocrelizumab. A total of 18 RRMS patients (35.3%) and 11 PPMS patients (50%) reported adverse events related to ocrelizumab. The most common adverse events were infusion-related reaction (e.g. fatigue, headache), and infection. Treatment discontinuation rate was 7.8% in RRMS 27.3% in PPMS patients – only 4 (5.5%) of which were due to adverse events.

Conclusions:

This real-world study of the effectiveness of ocrelizumab in MS is favorable and consistent with the clinical trials. Rate of treatment discontinuation in RRMS and PPMS was higher than reported in the clinical trials. More real-world evidence is required to assess the safety and tolerability of this medication.