A 9-year open-label extension analysis of the OPERA I and II studies demonstrated that ocrelizumab may provide sustained efficacy and a favorable safety profile in treatment-naive patients with early-stage relapsing multiple sclerosis. 

In the study, published in Neurology, researchers involved 757 patients, with 66.7% completing the 9-year follow-up.

The researchers found that 48.2% of the patients continuously treated with ocrelizumab (OCR) maintained no evidence of disease activity (NEDA) compared with 25.7% of those who switched from interferon (IFN) beta-1a to OCR (odds ratio = 2.72, 95% confidence interval [CI] = 1.94–3.82, P < .0001).

"A higher proportion of OCR-treated patients achieved NEDA status compared with [IFN]-treated patients during the [double-blind controlled treatment period], which was maintained throughout the [open-label extension]," stated lead study author João J. Cerqueira, MD, of the Life and Health Sciences Research Institute at the School of Medicine at the University of Minho in Braga, Portugal, and colleagues. "After switching to OCR, disability accrual and brain volume loss among [IFN]-treated patients became similar to the OCR-OCR group, but disability and brain volume loss accrued during [IFN] treatment were not recovered," they emphasized.

The patients in the OCR-OCR group also exhibited a significantly lower annualized relapse rate of 0.05 vs 0.09 in the IFN-OCR group (P = .0036). Brain volume loss and serum neurofilament light chain levels stabilized by week 96 in OCR-treated patients and remained stable through year 9.

Adverse event rates remained consistent, with infections reported at 65.94 per 100 patient-years and serious infections at 1.28 per 100 patient-years. No new safety concerns were identified.

The findings emphasized the long-term benefits of initiating OCR early in the disease course, reducing relapse rates, preserving brain volume, and delaying disability progression.

Full authors' disclosures are available in the study.