Immunotherapy and radiotherapy in metastatic uveal melanoma: Results from a single institute study.

Abstract

e21507 Background: Metastatic uveal melanoma carries a poor prognosis, especially for patients who are not eligible for Tebentafusp. Unlike cutaneous melanoma, checkpoint inhibitors have limited effect on uveal melanoma. The observation of Abscopal effect has inspired this study of adding radiotherapy to boost the efficacy of immunotherapy. Methods: We performed a retrospective study in Houston Methodist Hospital to evaluate the efficacy of combining immunotherapy with radiotherapy including either SBRT or Y-90 treatment. Clinical outcomes were determined by assessing best overall response according to the Response Evaluation Criteria in Solid Tumors (version 1.1), progression-free survival(PFS) and overall survival. Results: A total of 8 patients were included for this study, among which one patient had previously progressed on immunotherapy. The median follow-up period was 19 months. The best overall response rate (ORR) and disease control rate (DCR) were 25% and 75% in patients received dual-modality combination treatment (including one complete response and one partial response). The PFS and overall survival in dual-modality combination treatment group were 5.4 months (95% CI, 1.1 to 14.9 months) and 18.7 month (95% CI, 11.1 to 23.9 months), respectively. Fifty percent of patients experienced grade 3-4 treatment-related adverse events. Conclusions: The combination of radiotherapy and immunotherapy is active in metastatic uveal melanoma with sustained response in selected patients. A randomized prospective trial may be required to confirm the benefits of dual-modality combination treatment.[Table: see text]