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.