To assess the efficacy of earlier initiation of ocrelizumab on reaching key disability milestones, after 8.5 years of follow-up in the double-blind period (DBP) and open-label extension (OLE) of the pooled OPERA I/II (NCT01247324/NCT01412333) studies in patients with relapsing multiple sclerosis.

Early intervention using high-efficacy therapies to prevent disease progression is an increasingly adopted therapeutic strategy in multiple sclerosis, as reaching disability milestones is associated with increased patient and societal burden.

Patients completing the DBP either continued ocrelizumab (OCR-OCR) or switched from interferon β-1a to ocrelizumab (IFN-OCR) when entering the OLE period. Time-to-onset of 24-week confirmed disability progression to Expanded Disability Status Scale (EDSS) scores reflecting onset of impairment perceived by the patient (EDSS ≥2.0 from baseline EDSS ≤1.0), walking impairment (EDSS ≥4.0 from baseline EDSS ≤3.0) and requiring a walking aid (EDSS ≥6.0 from baseline EDSS ≤5.5) since DBP baseline were analyzed.

Over 8.5 years of the DBP and OLE, the risk of reaching key disability milestones was significantly lower in those who initiated ocrelizumab earlier (OCR-OCR) vs delayed treatment (IFN-OCR) (Hazard Ratio [95% confidence interval]): onset of disability (EDSS ≥2.0: n=9/61 vs n=20/82; 0.42 [0.19–0.94]; p=0.0303); walking impairment (EDSS ≥4.0: n=49/538 vs n=62/544; 0.69 [0.47–1.00]; p=0.0486); requiring a walking aid (EDSS ≥6.0: n=61/822 vs n=79/823; 0.67 [0.48–0.94]; p=0.0207). Over 8.5 years, 85.2%, 90.9% and 92.6% of OCR-OCR patients had not progressed to EDSS ≥2.0, EDSS ≥4.0 and EDSS ≥6.0 from the respective baseline.

After 8.5 years of follow-up, earlier treatment with ocrelizumab was associated with reduced numbers of patients reaching early disability milestones. Early institution of high-efficacy therapy can preserve function that is not regained when the same treatment is initiated later.