Estimating the Cost Burden of Adverse Effects Associated with Metastatic Melanoma Therapies in Italy

e17532 Background: Targeted therapy (TT), immunotherapy (IT), and chemotherapy (CT), which are commonly used in the treatment of MM, are frequently associated with adverse effects (AEs). This study estimated the per-event cost and overall cost burden associated with managing the most common and/or severe AEs for these 3 treatment categories from the Italian national healthcare system perspective. Methods: A literature review was conducted to evaluate the incidence and types of AEs associated with the 3 treatment categories. A total of 29 AEs (CT:11; TT:11; and IT:7), all-severity grades (Gr) occurring in >20% or Gr 3/4 occurring in >5%, were selected. Medical resource use related to the management of AEs was assessed by conducting 2 blinded Delphi panel cycles with 8 clinicians. The costs per AE were estimated using published unit costs and then combined with AE incidence (assuming 1 occurrence/patient) treatment usage, and 1-year prevalence of MM (498 cases) to estimate the treatment burden in Italy for a single AE occurrence. Results: The Table presents the top 3 cost-intensive AEs within each treatment category. Across all 3 treatment categories, the top 4 AEs with the highest overall burden on a population level were all Gr 3/4, were associated with CT or IT, and included neutropenia/leukopenia (mean total cost of €11,948), thrombocytopenia (€4579), diarrhea (€4514), and immune-related hypophysitis (€4288). Conclusions: In Italy, per-event costs for management of AEs associated with MM therapies can be substantial. The overall cost burden is likely to be underestimated since it does not account for AE recurrence. Treatment category and AEs Cost of each occurrence, € Mean ± SD Range Targeted therapy Rash, Gr 3/4 103.03 ± 67.20 21.88-186.29 Squamous cell carcinoma, Gr 3/4 92.17 ± 110.86 6.82-254.97 Skin papilloma, Gr 1/2 36.04 ± 10.99 21.03-46.99 Immunotherapy Immune-related hypophysitis, Gr 3/4 405.23 ± 140.34 250.54-524.39 Diarrhea, Gr 3/4 331.78 ± 337.99 53.66-707.96 Colitis, Gr 3/4 183.98 ± 109.98 71.54-291.32 Chemotherapy Neutropenia/leukopenia, Gr 3/4 803.82 ± 604.95 105.85-1177.18 Anaphylaxis, Gr 3/4 712.39 ± 456.70 192.17-1047.39 Thrombocytopenia, Gr 3/4 514.52 ± 364.10 132.20-857.15