A comparison of isolated limb infusion/perfusion, immune checkpoint inhibitors, and intralesional therapy as first‐line treatment for patients with melanoma in‐transit metastases

Background Isolated limb infusion and perfusion (ILI/ILP) has been a mainstay treatment for unresectable melanoma in‐transit metastases (ITM), but increased use of immune checkpoint inhibitors (ICI) and intralesional therapy (talimogene laherparepvec [TVEC]) introduced several different management options. This study compares first‐line ILI/ILP, ICI, and TVEC. Methods Retrospective review from 12 international institutions included patients treated from 1990 to 2022 with first‐line ILI/ILP, ICI, or TVEC for unresectable melanoma ITM. Results A total of 551 patients were treated, with ILI/ILP (n = 356), ICI (n = 125), and TVEC (n = 70) with median follow‐up of 5.5 years. Tumor burden was highest with ILI/ILP and lowest with TVEC (p = .002). Breslow thickness was lowest with TVEC (p = .007). TVEC was mostly used in stage IIIB disease versus IIIC for ILI/ILP and ICI (p = .01). Using ICI as the reference category, TVEC had the highest odds of a complete response (CR) (odds ratio, 1.96; p = .029) and a longer local progression‐free survival (PFS) (hazard ratio [HR], 0.40; p = .003). ILI/ILP had shorter local PFS (HR, 1.72; p = .012), PFS (HR, 1.79; p