OCR demonstrated superior efficacy to interferon treatment in patients with relapsing MS.  The effects of OCR in patients with a suboptimal responses to several DMTs requires additional assessment.

To report 1-year interim analysis results of the Phase IIIb CHORDS study (NCT02637856) evaluating ocrelizumab (OCR) in patients with relapsing-remitting multiple sclerosis and a suboptimal response to previous disease-modifying treatment (DMT).

The CHORDS intention-to-treat (ITT) population includes 608 patients who discontinued a DMT after at least 6 months of stable use due to suboptimal response (≥1 clinically reported relapse, ≥1 T1 gadolinium-enhancing [Gd⁺] lesion(s) or ≥2 new or enlarging T2 lesions). Patients receive OCR 600 mg every 24 weeks for up to 96 weeks. The primary endpoint is the proportion of patients free of protocol-defined clinical or MRI activity, evaluated in a modified ITT population excluding those who terminated treatment early for reasons other than lack of efficacy or death and had no evidence of clinical disease activity at the time of discontinuation. Safety was evaluated in the ITT population.

All 608 patients (baseline mean [SD] time since diagnosis, 4.2 [3.03] years) had 48 weeks of follow-up by June 15, 2018. The adjusted annualized relapse rate in ITT patients was 0.065.  Over 48 weeks, most patients in the modified ITT population did not experience protocol-defined relapse (92.6%), have T1 Gd⁺ lesions (96.1%) or new/enlarging T2 lesions (61.6%), or 24-week confirmed disability progression (94.5%). Overall, 54.5% of patients were free of any of these events. Interim safety data were consistent with previous observations.

This interim analysis of the full CHORDS population provides a 1-year positive benefit/risk profile of ocrelizumab in patients who experienced a suboptimal treatment response on another DMT.