Subcutaneous ocrelizumab in patients with multiple sclerosis: results of the phase III OCARINA II study

<h3>Objectives</h3> OCARINA II (NCT05232825) is a Phase III, randomised, open-label, controlled study of a novel subcutaneous formulation of ocrelizumab, designed to demonstrate non-inferior serum exposure of subcutaneous vs intravenous administration in relapsing and primary progressive multiple sclerosis (RMS/PPMS). <h3>Methods</h3> Patients were randomised 1:1 to receive ocrelizumab 920mg SC or 600mg IV first dose, all patients would then receive 920mg SC every 24 weeks, to week 96. Key endpoints were serum ocrelizumab area under the concentration-time curve from baseline to Week 12 (primary endpoint, AUCW1–12), and MRI activity, relapses, immunogenicity, B-cell depletion and safety. <h3>Results</h3> 236 patients were randomised. At W12, the geometric mean ratio (90% CI) for AUCW1–12 of ocrelizumab SC vs IV was 1.29 (1.23–1.35). OCR SC, resulted in near-complete suppression of MRI and relapse activity to W24, and rapid and sustained B-cell depletion was observed, similarly to OCR IV. The safety profile was consistent with that of OCR IV 600mg, no additional safety concerns were identified for ocrelizumab or subcutaneous administration. <h3>Conclusions</h3> OCR SC 920mg demonstrated non-inferiority to IV 600mg in AUCW1–12, and similar clinical and imaging measures were demonstrated. The subcutaneous formulation has potential to deliver the clinical benefits of ocrelizumab IV while providing additional treatment flexibility.