Evaluating the efficacy and safety of transitioning patients with multiple sclerosis from natalizumab to ocrelizumab (OCTAVE).

Natalizumab is associated with a risk of progressive multifocal leukoencephalopathy (PML) in multiple sclerosis (MS) patients infected with John Cunningham virus (JCV). Ocrelizumab has demonstrated efficacy to treat MS; however, its safety in patients previously treated with natalizumab is unclear. To evaluate the safety and efficacy of ocrelizumab in patients with relapsing MS (RMS) previously treated with natalizumab. Clinically and radiographically stable RMS patients, ages 18-65 treated with natalizumab for ⩾ 12 months, were enrolled in the study and initiated ocrelizumab 4-6 weeks after their final dose of natalizumab. Relapse assessment, expanded disability status scale, and brain magnetic resonance imaging (MRI) were performed prior to starting ocrelizumab and at months 3, 6, 9, and 12. Forty-three patients were enrolled, and 41 (95%) completed the study. Two patients had a relapse while on ocrelizumab, one at month 9 and the other at month 12, without changes on brain MRI. Two additional patients had new brain MRI lesions detected at month 3, with no new symptoms. Thirteen serious adverse events (SAEs) were recorded, four of which were considered possibly related to ocrelizumab. Overall, our study indicates clinical and MRI stability for most patients transitioning from natalizumab to ocrelizumab. NCT03157830.