Real-world evidence of clinical outcomes and adherence to ofatumumab in the UK and the impact of a patients support programme: A retrospective, non-interventional cohort study

BACKGROUND: Ofatumumab is the only anti-CD20 monoclonal antibody disease modifying therapy available for self- administration for adults with active relapsing remitting multiple sclerosis (RMS). This study aimed to investigate real-world adherence and clinical outcomes of ofatumumab-treated patients in the UK and looked at the impact of a patient support program called Kesimpta Connect (KC PSP) on these outcomes. METHODS: This retrospective observational cohort study examined adherence to ofatumumab in 155 RMS patients recruited from six UK MS centres. The primary objective of the study was to describe the medication possession ratio (MPR) adherence of ofatumumab treated patients over a 13-month period. The study also looked at clinical effectiveness measures, including change in annualized relapse rates (ARR). Safety and secondary-care use was also assessed in this study. RESULTS: 103 patients had data available to be assessed for adherence and clinical effectiveness. 87 % (n=90) of patients had an MPR adherence of 0.80 or greater and higher proportion of non-KC PSP users reported adherence of greater than 0.80 than KC PSP users (98.4 % vs 69.2 %). The total ARR decreased during the follow-up period from 0.33 (95 % CI 0.23-0.40) prior to ofatumumab initiation to 0.06 (95 % CI 0.01-0.11) 12-months after initiation. In terms of safety, 38.1 % (n=59/155) patients reported experiencing an adverse event during the follow-up period; one was reported to be severe. However, no patients reported discontinuing ofatumumab during the study follow-up period. CONCLUSION: This study provides evidence of good adherence for RMS patients using ofatumumab. Further, there is evidence of clinical effectiveness based on reduction in ARR post-ofatumumab initiation, as well as tolerability and a favourable safety profile. The results of this study support the continued use of ofatumumab in providing effective RMS disease management in the UK NHS.