OBJECTIVES: To estimate the cost-effectiveness (CE) of switching to natalizumab (NAT) compared with switching to fingolimod (FTY) for highly active relapsing-remitting multiple sclerosis (RRMS) patients with inadequate response to first line therapies (BRACETD) from the perspective of NHS Scotland using real-world data (RWD) from the MSBase Registry.
METHODS: A Markov model with health states based on the Expanded Disability Status Scale (EDSS) was developed to capture RRMS progression, conversion to secondary progressive MS, and associated relapses. Treatment-specific EDSS transition matrices, annualized relapse rates by EDSS state and comparative effectiveness results were obtained from 3-way propensity score matched cohorts from MSBase (companion paper submitted at this meeting). Costs and utilities for disease management and relapses were taken from the United Kingdom (UK) MS Survey 2016. Treatment costs were based on UK list prices with discounts considered in scenario analyses. Additional clinical data were obtained from the published literature and other publicly available sources. Scottish general mortality data were utilized. The CE analysis estimated lifetime clinical and economic outcomes and the incremental cost per quality-adjusted life-year (QALY) gained. Extensive scenario and sensitivity analyses were conducted to estimate the impact of alternative data sources, assumptions, and parameter uncertainty on CE outcomes.
RESULTS: The MSBase analysis suggests that patients experiencing disease activity on BRACETD clearly benefit from therapy escalation to NAT as compared to switching among BRACETD. The benefit was less marked for the therapy escalation to FTY. In the base-case CE analysis, NAT dominated FTY, leading to higher QALYs (0.393 higher per patient) and lower costs (₤19,148 lower per patient). NAT remained dominant across scenarios considering a societal perspective, alternative discount rates, a 10-year time horizon, and equal treatment discontinuation rates. For FTY price discounts up to 23.2%, NAT remained dominant; for FTY discounts of up to 32.8% and 37.6%, NAT remained cost-effective at thresholds of ₤20,000/QALY and ₤30,000/QALY, respectively.
CONCLUSIONS: In this analysis, switching to NAT dominated switching to FTY in highly active RRMS with inadequate response to BRACETD. NAT remained dominant across a range of alternative scenarios and was likely to be cost-effective with up to a 32.8-37.6% discount on the price of FTY.
