OBJECTIVES: Multiple sclerosis is a neurodegenerative disorder with high economic and social burden due to its potential to cause severe disability. Around 85% of cases start as relapsing remitting MS (RRMS) but increasing number of patients gradually convert to secondary progressive MS (SPMS). The objective of this study is to evaluate the cost effectiveness of siponimod vs natalizumab for SPMS from the Turkish public payer’s (SGK) perspective.

METHODS: A discrete-time Markov chain (DTMC) model was designed. The model duration was lifetime with a cycle length of one year. Both costs and outcomes were discounted at 3%. A matching indirect comparison was performed to compare siponimod results from the EXPAND study and natalizumab results from the ASCEND study for effectiveness in patients with active SPMS. Treatment costs included drug acquisition costs (reimbursement prices), drug administration and monitoring costs, disease management costs by EDSS scores, adverse event costs and relapse costs. A health care resource utilization tool was designed and completed by experts to estimate the costs. All costs were calculated based on the reimbursement rules and price tariffs of the SGK. Both one-way and probabilistic sensitivity analyses were made.

RESULTS: Total life years was 13,02 for siponimod and 12,55 for natalizumab. Total costs were 1,394,855 TRY and 1,275,090 TRY for siponimod and natalizumab respectively. The ICER was 254,065 TRY for life years and 177,371 TRY for QALYs. Sensitivity analysis results showed that the conclusions of the model were robust.

CONCLUSIONS: Turkey does not have a published threshold for cost-effectiveness analysis. The GDP per capita was 85.672TRY in 2021. Based on the GDP per capita threshold (three times the GDP per capita= 257.016 TRY), siponimod, which significantly reduced the risk of disability progression compared to placebo in the EXPAND Phase III clinical trial, compared with natalizumab, is a cost-effective option in Turkey.