What happened
Published online on 5 October 2026, the full OPERA I and II follow-up analysis covers 1,656 people randomized with relapsing multiple sclerosis (MS). Ocrelizumab was compared with interferon beta-1a for two blinded years; participants entering the open-label extension then received ocrelizumab for up to eight more years. Across the full period, earlier ocrelizumab was associated with a lower hazard of disability progression confirmed for 48 weeks (hazard ratio 0.76; 95% confidence interval 0.61–0.95). The difference was largely established during the randomized period. After the switch, the extension-only comparison did not show a new difference (hazard ratio 1.02; 95% confidence interval 0.81–1.28).
What this means for people with MS
This adds full peer-reviewed long-term evidence for earlier treatment in relapsing MS, but the 10-year comparison was not randomized throughout: 853 of 1,656 originally randomized participants completed follow-up. Attrition and post hoc analysis limit causal interpretation. The 10-year comparison for progression independent of relapse activity (PIRA) was not statistically significant; this paper does not prove remyelination or effects in primary progressive MS. Serious infections and declining IgG occurred, so stable observed adverse-event rates do not mean no risk. This paper does not establish Greek availability or reimbursement.
About the approach studied in this programme: OPERA I and II (ocrelizumab)
Ocrelizumab is an antibody that binds CD20 on B cells and reduces that immune-cell population. OPERA I and II compared this approach with interferon beta-1a for relapsing MS during the randomized period, then followed participants receiving ocrelizumab in an open-label extension; the extension is not a continuing randomized comparison.
Approach source: JAMA Neurology — original OPERA follow-up article ↗
- What kind of evidence exists?
- Peer-reviewed JAMA Neurology original investigation; 2-year randomized comparison followed by open-label extension
- How reliable is this source?
- JAMA Neurology peer-reviewed original paper dated 5 October 2026; Roche funded the study and participated in design, analysis, interpretation and editorial work. Official OPERA I/II registry records checked separately.
- Research event/source date
- Published by MyelinWatch
- Last substantive MyelinWatch update