BERLIN—Switching from interferon beta-1a to ocrelizumab after two years at the start of the OPERA I and OPERA II open-label extension period was associated with a rapid reduction in annualized release rate, according to a report presented at ECTRIMS 2018. “Both patients who continued treatment with ocrelizumab as well as those who were switched from interferon beta-1a to ocrelizumab maintained their robust reduction in annualized relapse rate through the three-year follow-up of the open-label extension period,” said lead author Stephen L. Hauser, MD, Director of the UCSF Weill Institute for Neurosciences, University of California, San Francisco, and colleagues.
“After five years of follow-up, the proportion of patients with disability progression was lower in patients who initiated ocrelizumab treatment earlier, compared with patients who received initial interferon treatment before switching to ocrelizumab, showing that patients who initiated ocrelizumab two years earlier accrued significant and sustained reductions in disability progression compared with patients switching from interferon therapy.”
The efficacy and safety of ocrelizumab in relapsing multiple sclerosis (MS) were demonstrated in the 96-week double-blind control period of OPERA I and OPERA II, and results for the two-year follow-up of the pooled OPERA I and OPERA II open-label extension period have previously been reported. For this study, Dr. Hauser and colleagues sought to assess the efficacy of switching to or maintaining ocrelizumab therapy on clinical measures of disease activity and progression after three years of follow-up in the open-label extension period of the OPERA I and OPERA II phase III trials in relapsing MS.
At the start of the open-label extension period, patients continued ocrelizumab therapy or were switched from interferon beta-1a to ocrelizumab. The researchers analyzed adjusted annualized relapse rate (ARR), time to onset of 24-week confirmed disability progression, and change in adjusted mean Expanded Disability Status Scale (EDSS) score from baseline.
Overall, 88.6% of patients who entered the open-label extension completed year three of follow-up. Among patients who switched therapy, annualized release rate decreased from 0.20 in the year preswitch to 0.10, 0.08, and 0.07 at years one, two, and three postswitch. Those patients who continued on ocrelizumab maintained a low annualized relapse rate through the year prior to the open-label extension and the three years of the open-label extension period (0.13, 0.11, 0.08, and 0.07). In addition, those patients who continued on ocrelizumab versus those who switched therapy had lower proportions of patients with 24-week confirmed disability progression in the year preswitch and years one, two, and three of the open-label extension period (7.7%/12.0%, 10.1%/15.6%, 13.9%/18.1%, and 16.1%/21.3%).
This study was sponsored by F. Hoffmann-La Roche, and writing and editorial assistance was provided by Articulate Science, UK.