Cost-effectiveness of Response-Adapted De-escalation of Immunotherapy in Advanced Melanoma

Importance Combination immunotherapy with nivolumab and ipilimumab has markedly improved outcomes for patients with advanced melanoma. However, these therapies pose a considerable financial burden to both patients and the health care system. The ADAPT-IT trial demonstrated comparable progression-free and overall survival for patients with response-adapted ipilimumab discontinuation compared with standard of care (SOC). Objective To determine the cost-effectiveness of ipilimumab discontinuation for patients with interim imaging-confirmed tumor response in the treatment of advanced melanoma. Design, Setting, and Participants This cost-effectiveness analysis was performed using data from the ADAPT-IT (follow-up of 33 months) and CheckMate 067 (follow-up of 6.5 years) trials, as well as published literature over the ADAPT-IT trial duration of 33 months. The analysis was performed in a US setting from a US-payer perspective, and the willingness-to-pay (WTP) threshold was set at $100 000/quality-adjusted life-year (QALY). A total of 355 patients with previously untreated melanoma (unresectable stage III or IV metastatic melanoma) were included. Exposure Response-adapted ipilimumab discontinuation compared with SOC therapy. Main Outcomes and Measures The primary outcomes of the CheckMate trial were overall survival and progression-free survival, while that of ADAPT-IT was objective response. This informed a decision model to estimate lifetime costs and QALYs associated with both strategies. Incremental cost, effectiveness, and cost-effectiveness ratio were assessed. Sensitivity and scenario analyses were performed to account for variability in trials and input parameters. Results Of the 355 patients included in the analysis, 41 patients were from the ADAPT-IT trial (median age, 65 years; 28 [68%] male) and 314 patients from the CheckMate 067 trial (median age, 61 years; 206 [66%] male). Response-adapted treatment was the cost-effective option in 94.0% of scenarios based on Monte Carlo simulations, with a dominant incremental cost-effectiveness ratio and an incremental net monetary benefit of $28 849 compared with SOC therapy. Cost savings were estimated at $19 891 per patient compared with SOC. In scenario analyses, current SOC was only considered as a cost-effective option under best survival assumptions and if the willingness-to-pay threshold exceeded $630 000/QALY. Conclusions and Relevance This economic evaluation demonstrated that response-adapted treatment de-escalation in patients with advanced melanoma may lead to considerable savings in health care costs and could represent the most cost-effective strategy across various resource settings. Future trials should aim to provide further evidence on noninferiority.