Immunoembolization for patients with uveal melanoma hepatic metastasis: A single-institution real-world data analysis.

9586 Background: Metastatic disease occurs in up to 50% of patients with uveal melanoma (UM) despite successful treatment of the primary eye tumor. The liver is the predominant organ of involvement in more than 90% of patients, and control of liver metastases is essential to prolonging overall survival (OS). Immunoembolization (IE) with granulocyte-macrophage colony-stimulating factor +/- interleukin-2 is considered a 1 st line liver-directed therapy for those with <50% hepatic tumor burden at our institution. It is well tolerated, has limited side effects, no cumulative toxicities, and affords good quality of life between scheduled treatments. Methods: A retrospective single-institution chart review was performed on consecutive series of metastatic UM (MUM) patients with hepatic metastasis who were treated at Thomas Jefferson University with IE treatment. The following data were collected from medical records: age, gender, IE treatment history, treatment history before and after IE, last follow-up date, and date of death. Results: 604 MUM patients (median age 62, range 19-91) received IE treatment for UM hepatic metastasis from 11/2000 to 01/2025 for a total of 3,715 IE treatments. 22 patients continue to receive IE. Patients received a median of 4 IE treatments (range 1-45) over 4 months (range 1-118 months). With a median follow-up of 18.3 months (range 0.1-176.4), median OS after IE treatment initiation was 20.0 months (95%CI 18.2-22.3). OS was 73.2% at 1 year, 41.8% at 2 years, 25.3% at 3 years, and 11.2% at 5 years. 30% of patients had treatment of metastatic disease prior to IE and 83% had treatment after IE. 134 patients (22%) had concurrent therapy with IE, most commonly checkpoint inhibitor therapy (48%). Median OS was 21.5 months (95%CI 18.9-23.4) for patients who received IE as first-line metastatic therapy. Except for one patient who died of takotsubo cardiomyopathy after the first IE treatment, IE treatments were well tolerated without serious or long-term complications. Of the subset of patients that experienced a prolonged OS of ≥3 years with IE (n=117), they received a median of 10 treatments over 16 months. Of the patients with prolonged OS of ≥5 years with IE (n=33), they received a median of 12 treatments over 19 months. Patients that experienced prolonged OS with IE ≥3 years were more likely to be female (69%). The longest patient treated with IE was a female who received 45 IE treatments over 10 years. Conclusions: We conducted the largest retrospective study of MUM patients who have received IE treatment. Our real-world data indicates that IE is a safe and effective liver-directed therapy for UM hepatic metastases, and IE should be considered a mainstay of treatment for patients with limited hepatic tumor burden.