Safety and efficacy of opicinumab in participants with relapsing multiple sclerosis (AFFINITY Part 1): A randomized, controlled, phase 2 trial

Background: Opicinumab, a human monoclonal antibody against LINGO-1, is hypothesized to promote remyelination by enhancing the differentiation of oligodendrocyte progenitor cells. Objective: The objective of the study is to investigate the efficacy and safety of opicinumab as an add-on therapy to anti-inflammatory disease-modifying therapies (DMTs) in participants with relapsing multiple sclerosis (RMS). Methods: Participants with RMS aged 18–58 years, with disease duration up to 20 years, were randomized 1:1 to receive intravenous infusions of placebo or opicinumab every 4 weeks for 72 weeks. Primary endpoint was Overall Disability Response Score (ODRS) over 72 weeks. Results: The study enrolled 263 participants. Adjusted mean difference (95% confidence interval (CI)) on ODRS was 0.15 (−0.05 to 0.35; p = 0.148) over 72 weeks, favoring opicinumab versus placebo. Numerically larger differences in favor of opicinumab were observed in participants aged ⩾ 40 years with Expanded Disability Status Scale ⩾ 3.0, with disease duration ⩾ 6 years, and receiving dimethyl fumarate as the background DMT. 85% participants in placebo group and 86% in opicinumab group had adverse events. Conclusion: Although the AFFINITY study did not show significant difference in mean ODRS between opicinumab and placebo groups, data from AFFINITY interpreted with the previous SYNERGY study may inform the design of future remyelination trials. Clinicaltrials.gov identifier: (NCT03222973).