Abstract| Volume 37, 101593, January 2020

Long-Term Reduction of Relapse Rate and Confirmed Disability Progression After 6 Years of Ocrelizumab Treatment in Patients with Relapsing Multiple Sclerosis

      The efficacy and safety of ocrelizumab (OCR) in relapsing multiple sclerosis (RMS) were demonstrated in the 96-week controlled double-blind period (DBP) of the Phase III trials OPERA I and OPERA II (NCT01247324; NCT01412333). Results for the 3-year follow-up of the pooled OPERA open-label extension (OLE) period have previously been reported (Hauser SL, et al. ECTRIMS 2018;Abstract P590).
      At the start of the OLE period, patients who completed the DBP either continued OCR (OCR-OCR) or were switched from interferon (IFN) β-1a to OCR (IFN-OCR). Adjusted annualised relapse rate (ARR), time to onset of 24-week confirmed disability progression (CDP24) and change in adjusted mean Expanded Disability Status Scale (EDSS) score from the DBP baseline were analysed.
      Overall, 82.3% of patients who entered the OLE completed OLE study Year 4. Among IFN-OCR patients, ARR decreased from 0.20 in the year pre-switch to 0.10, 0.08, 0.07 and 0.04 at Years 1, 2, 3 and 4 post-switch (Year 1 vs pre-switch, p<0.001; Year 1 vs Year 2, p=0.31; Year 2 vs Year 3, p=0.56; Year 3 vs Year 4, p=0.05). OCR-OCR continuers maintained the low ARR through the year pre-OLE and the 4 years of the OLE period (0.13, 0.10, 0.08, 0.07 and 0.05). OCR-OCR continuers vs IFN-OCR switchers had lower proportions of patients with CDP24 in the year pre-switch (7.7% vs 12.0%), and at OLE Year 1 (10.1% vs 15.6%), OLE Year 2 (13.9% vs 18.1%), OLE Year 3 (16.2% vs 21.3%), and OLE Year 4 (19.2% vs 23.7%); p<0.05, all difference comparisons. The safety profile observed in the OLE was generally consistent with that observed during the DBP.
      After 6 years of follow-up, the proportion of patients with CDP24 remained lower in patients who initiated ocrelizumab treatment earlier (OCR-OCR), compared with patients who received initial IFN treatment (IFN-OCR), demonstrating that the benefits of earlier initiation of ocrelizumab were maintained compared with patients switching from IFN. Switching from IFN to ocrelizumab after 2 years at the start of the OLE period was associated with a reduction in ARR. Both OCR-OCR and IFN-OCR patients maintained their reduction in ARR through the 4-year follow-up of the OLE period.