Isolated Limb Infusion or Perfusion as First-Line Versus Second-Line Therapy for In-Transit Metastatic Melanoma

Area of Science:

• Oncology
• Surgical Oncology
• Melanoma Research

Background:

• In-transit metastases (ITM) affect 10% of high-risk melanoma patients.
• Isolated limb infusion and perfusion (ILI/ILP) are established treatments for ITM.
• The optimal timing for ILI/ILP in the treatment sequence remains undefined.

Purpose of the Study:

• To compare the efficacy of isolated limb infusion and perfusion (ILI/ILP) when used as either first-line or second-line therapy for unresectable melanoma in-transit metastases (ITM).

Main Methods:

• A retrospective international multi-institution study analyzed data from 364 patients with unresectable ITM treated with ILI/ILP between 2006 and 2023.
• Patients were categorized based on whether ILI/ILP was administered as first-line (n=329) or second-line (n=35) therapy.
• Outcomes including overall response rate (ORR), in-field progression-free survival (PFS), out-of-field PFS, and overall survival (OS) were evaluated.

Main Results:

• The overall response rate (ORR) was significantly higher for first-line ILI/ILP (84%) compared to second-line (68%) (P=0.02).
• Complete response (CR) and partial response (PR) rates were 84% for first-line versus 67% for second-line.
• No statistically significant differences were observed in median in-field PFS (10.8 vs. 8.1 months; P=0.2), out-of-field PFS (13.5 vs. 15.3 months; P=0.4), or overall survival (4.1 vs. 4.5 years; P=0.7) between the two groups.

Conclusions:

• Both first- and second-line ILI/ILP demonstrate high overall response rates for unresectable melanoma ITM.
• Despite a higher ORR with first-line therapy, the lack of difference in in-field PFS suggests ILI/ILP is an effective salvage therapy when used as a second-line treatment.