OBJECTIVES: Belantamab mafodotin (belamaf) and melphalan flufenamide in combination with dexamethasone (MEL+DEX) have been approved for heavily pretreated relapsed/refractory multiple myeloma (RRMM) patients. Hefty price tags of each highlight the need to evaluate the relationship between the costs and outcomes achieved by these therapies. The objective of the research is to evaluate the cost-effectiveness of belamaf compared with MEL+DEX in RRMM patients who have received at least four prior lines of therapy from a U.S. commercial payer perspective.

METHODS: A partitioned survival model with three health states (progression-free, progressed, and dead) was developed to estimate the overall survival (OS) and progression-free survival (PFS) based on the results from pivotal clinical trials for belamaf (DREAMM-2) and MEL+DEX (HORIZON). The cost categories included drug acquisition and administration, concomitant medication, adverse event management, treatment monitoring, disease management, and terminal care costs. The model was developed with a lifetime horizon and 3% annual discount rates for costs and health outcomes. Sensitivity analyses were conducted to assess the uncertainty associated with individual model inputs.

RESULTS: Over a lifetime horizon, belamaf was associated with higher incremental costs of $38,391 and increased overall life years and quality-adjusted life years (QALY) by 0.33 and 0.31, respectively compared to MEL+DEX. The incremental cost-effectiveness ratio (ICER) of belamaf vs. MEL+DEX was $125,352 per QALY gained. Sensitivity analysis showed that the model was most sensitive to variations in parameters for estimating OS and PFS, followed by drug acquisition and adverse event management costs.

CONCLUSION: Belamaf demonstrated clinical benefits with an increase in PFS and OS, which contributed to higher incremental treatment costs compared to MEL+DEX. The results of the study suggest that belamaf is potentially a cost-effective therapy compared to MEL+DEX for heavily pretreated RRMM patients under the commonly used willingness-to-pay threshold range of $100,000 to $150,000 in the U.S.