Cost Estimate of Immune-Related Adverse Reactions Associated with Innovative Treatments of Metastatic Melanoma.

Background and Objective: Immuno-oncology therapies represent a new treatment opportunity for patients affected by metastatic melanoma. The purpose of this study was to estimate the costs of immune-related adverse events (irAEs) associated with the new anti-PD1 immuno-oncology therapies, with the anti-CTLA-4 immuno-oncology therapy and with the combined therapy (CTLA4 + anti-PD1) in patients affected by metastatic melanoma. Materials and Methods: A probabilistic cost-of-illness (COI) model was developed to estimate the management costs of grade ≥ 3 adverse events associated with the new anti-PD1 therapies (pembrolizumab and nivolumab), the anti-CTLA-4 therapy (ipilimumab) and the combined therapy CTLA4 + anti-PD1 (nivolumab + ipilimumab) for the treatment of patients with metastatic melanoma from the National Health Service (NHS) perspective in Italy. Identification of the epidemiological and cost parameters was carried out through a systematic literature review (SLR). Univariate and probabilistic sensitivity analyses were performed to account for uncertainty and variation in the model results. Results: The model estimated a cost associated with the management of grade ≥ 3 immune-related adverse events in patients with metastatic melanoma equal to €176.2 (95% CI 63.5–335.0) for anti-CTLA-4 therapy, €48.6 (95% CI 40.1–58.5) for the new anti-PDI therapies and €276.8 (95% CI 240.4–316.2) for the combined therapy. Among the innovative therapies for the considered metastatic melanoma, the combined therapy was the most expensive innovative treatment in terms of event management of immune-related grade ≥ 3 adverse events. Conclusion: This study may represent a useful tool to understand the economic burden associated with the management of irAEs associated with patients affected by metastatic melanoma.