Percutaneous hepatic perfusion (PHP) with melphalan for treatment of liver metastases from uveal melanoma: Initial commercial experience.

Abstract

e21532 Background: Approximately 50% of patients with uveal melanoma (UM) develop metastases with the liver being the primary site of disease in > 90% of cases. Control of hepatic tumors is critical to prolonging overall survival for patients with metastatic uveal melanoma (MUM). We report our initial single institution experience with commercially available PHP with melphalan (HEPZATO, Delcath, Queensbury, NY) for the treatment of UM hepatic metastases. Methods: MUM patients with < 50% hepatic tumor burden underwent commercially available PHP at 6 to 8-week intervals. Best radiographic response was assessed with contrast-enhanced MRI using RECIST 1.1 criteria. CTCAE v5.0 was used to assess adverse events. Results: Sixteen patients (6 men; median age, 60; range, 31–73) including 7 patients with extrahepatic metastasis, underwent PHP (n = 43 procedures) from March 2024 to January 2025. All patients had at least one prior liver-directed therapy (LDT), and 6 out of 7 patients failed prior systemic treatment. Patients underwent a median of 2 PHPs (range 1-5), and 14 patients had ≥ 2 procedures. Median follow-up was 4.8 months (range, 0.5 – 10.4). Fifteen patients are still alive after initial PHP [median, 4.4 months (range 0.5-10.4)]. Of the 12 patients who underwent follow-up MRI, 5 had stable disease (SD) and 3 demonstrated a partial response (67% disease control rate). Three patients with progression of disease (PD) after PHP underwent repeat treatment; one achieved SD while two have not yet undergone follow-up imaging. One patient stopped treatment due to intrahepatic and extrahepatic tumor progression. Twelve patients required transfusions following one (n = 8), two (n = 2), three (n = 1) or five (n = 1) PHPs. One patient developed grade 4 sinusoidal obstruction syndrome prohibiting additional LDT and died 5.9 months post PHP due to PD. One patient was hospitalized 2 weeks following PHP due to grade 4 thrombocytopenia and leukopenia requiring transfusions, antibiotics, and supportive care. Two patients developed grade 3 neutropenia requiring cancellation of subsequent procedures. Two patients experienced strokes precluding additional PHP treatments: one occurred 2 weeks post-treatment of unclear etiology but was diagnosed with a patent foramen ovale and echogenic material in the left atrium by trans-esophageal ECHO; the other occurred post-procedurally with near-complete symptom resolution on discharge. Another patient required intubation for 27 hours post procedure due to sustained metabolic acidosis. Conclusions: PHP remains a promising treatment for MUM patients. The durability of disease control is uncertain based on this early commercial experience, and it is unclear how PHP compares to other LDT for this disease. However, in our experience, procedural complications seem to be more significant, and treatment-limiting compared to alternative LDT.