Presentation (CTI)

OBJECTIVES: Multiple sclerosis (MS) is a chronic autoimmune disease. Canada’s Drug Agency’s (CDA) Canadian Drug Expert Committee (CDEC) has considered treatment for MS with disease-modifying therapies (DMTs) to prevent long-term disability. Long-term treatment effects (TE) of interventions influence cost-effectiveness outcomes in health economic modelling; the waning of DMTs TE over model time horizons and the application of stopping rules in MS has recently been debated in technology appraisals in the UK. This study aimed to investigate how consistently TE waning assumptions have been applied in CDA reimbursement reviews in MS and whether there is consensus within the CDEC regarding its inclusion.
METHODS: A targeted search of the CDA website was conducted for reimbursement reviews in MS published from inception to 23 October 2024. The retrieved records were exported into Excel and screened for indication and review relevance. The published pharmacoeconomic reports of eligible reviews of DMTs in MS were retrieved and appraised for TE waning in their economic modelling. Information was extracted on TE waning assumptions, methodology, and rationale.
RESULTS: In total, 16 of 87 screened reviews were included: these were reviews of DMTs in MS which were published with CDEC recommendations. Of these, 5 reviews applied TE waning assumptions and/or stopping rules in the company or CDA base case analysis, or the scenario analysis. Across the reviews, the application of relative TE waning varied from a 30% reduction after 3 years, 50% after 5 years, and 70% after 9 years, to a 25% reduction after 2 years and 50% after 4 years.
CONCLUSIONS: There is inconsistency concerning the acceptance or rejection of the modelling of TE waning in MS across reimbursement reviews. This is dependent on assumptions of loss of DMT efficacy, either being due to progression of disease or loss of intervention effect in the form of MS.