Natalizumab treatment satisfaction in the TONiC-MS study: study design

BackgroundThe Trajectories of Outcome in Neurological Conditions-MS (TONiC-MS) is an ongoing observational study of people with MS in the UK, collecting patient reported outcome measures. In 2021, natalizumab became available in s.c. formulation in addition to the i.v. formulation first licensed in UK in 2006. There are currently no data on patient preference between the two formulations.MethodsThis is a prospective, observational, open-label questionnaire study nested in the TONiC-MS study. Following informed consent, participants on natalizumab-i.v. in TONiC-MS receive a baseline question- naire pack covering: treatment duration, frequency of administration, cannulation experience; adverse events; Neurological Fatigue Index-MS; Hospital Anxiety and Depression Scale; Stigma Scale for Chronic Illness; WHOQol-BREF; MSIS 29 Psychological; Warwick-Edinburgh Mental Well-being Scale. If the subject switches to natalizumab-s.c., one and three months later they will complete a follow-on pack repeating the above alongside the Patient Preference Questionnaire.ResultsEnrolment of participants on natalizumab-i.v. started in August 2021. Study design and interim data will be presented.DiscussionThis study will provide real-world data on experience with natalizumab-i.v. and natalizumab-s.c. in the UK. The data collected will allow examination of quality of life, MS psychological impact, well-being and adverse events on the different formulations of natalizumab.