A Model-Based Economic Evaluation of Cladribine Versus Alemtuzumab, Ocrelizumab and Natalizumab for the Treatment of Relapsing-Remitting Multiple Sclerosis with High Disease Activity in Chile

PURPOSE: The aim of this study was to evaluate the cost effectiveness of cladribine compared with alemtuzumab, natalizumab, and ocrelizumab for the treatment of highly active multiple sclerosis (HAD-MS) from the perspective of the Chilean health care public sector. MATERIALS AND METHODS: A Markov model was used to compare costs and quality-adjusted life-years (QALYs) over a 45-year time horizon using a 3% discount rate for costs and outcomes. Natural history of the disease was modeled in terms of progression of disability according to the Expanded Disability Status Scale (EDSS). A network meta-analysis was used as a source of comparative effectiveness for disability progression and annual relapse rates. Differences in costs and outcomes were modeled for only 10 years due to high temporal uncertainty. Ocrelizumab was assumed to have the same efficacy as cladribine due to lack of data. Direct costs were taken from national tariffs and expressed in 2019 US dollars. Utilities for EDSS health states were obtained from the literature. Second-order uncertainty was characterized through deterministic and probabilistic sensitivity analysis. FINDINGS: Compared with natalizumab (the current strategy covered in Chile), cladribine is associated with incremental costs and QALYs of US$70,989 and 1.875, respectively (incremental cost-effectiveness ratio [ICER] $37,861). Ocrelizumab was extendedly dominated by cladribine and natalizumab, and alemtuzumab was dominated by cladribine. A scenario analysis of a 10% discount did not modify the results substantially, but showed a decrease in the ICER of cladribine versus natalizumab (ICER $29,833/QALY). IMPLICATIONS: Cladribine is a new oral alternative to treat patients with HAD-MS that is expected to produce higher QALYs than all evaluated alternatives. In the context of a conservative analysis, cladribine cannot be considered cost effective for the Chilean health care public sector using a 1 GDP per capita threshold. However, under reasonable discount scenarios, cladribine becomes an attractive alternative for the health system.