Tebentafusp in metastatic uveal melanoma patients: Results of the Italian expanded access program.

Abstract

e21533 Background: Tebentafusp has become a standard of care for metastatic uveal melanoma patients positive for HLA-A*02:01 after the results of the phase III trial, which demonstrated a survival advantage. Here we present the real-world data from the Italian expanded access program (EAP) with tebentafusp. Methods: All the patients treated with tebentafusp in Italian EAP were considered in this study. Results: 52 patients from 12 centers have been included, 27 males and 25 females. The median age was 58.7 years (38-87). 29 patients received tebentafusp as first line therapy, 23 patients have been previously treated with systemic therapies. After a median follow-up of 28 months, median overall survival (OS) of the whole population was 12.2 months, with 1 year survival rate of 52% (62.1% for patients treated in first line setting). Median progression-free survival (PFS) was 3.6 months, with 6 months PFS rate of 30.8% (37.9% for patients treated in first line setting). OS of patients who received tebentafusp as first line therapy was 21.5 months (95% CI 11.9-31.1), while 7.7 months (95% CI 6.3-9.1) for patients treated with tebentafusp after other systemic therapies (p = 0.020). PFS of tebentafusp for untreated patients was 5.1 months (95% CI 2.1-8.1), 2.8 months (95% CI 1.9-3.8) for previously treated patients (p = 0.021). Patients with basal LDH higher than upper normal level had shorter survival than patients with normal basal LDH (7.4 months versus not reached, respectively, p < 0.001). During the therapy with tebentafusp, 12 patients underwent locoregional treatments (i.e. radiotherapy, chemoembolization). OS of these patients was 17.8 months, while OS of patients not treated with locoregional treatments was 9.1 months (p = 0.29). OS was not reached ( > 30 months) for patients who received tebentafusp as first line therapy and concomitant locoregional treatments. Objective response was 9.6%, clinical benefit (complete response + partial response + stable disease) 39%. Patients with objective response had a longer survival than patients without objective response, respectively not reached vs 10.6 months (p = 0.008). A longer OS was also observed in patients with clinical benefit (32.4 months) compared to patients without clinical benefit (6.9 months - p < 0.001). 26 patients were treated with tebentafusp beyond progression. 31 patients (52.5%) experienced an adverse event (any grade); among them, 5 patients (9.6%) had a grade 3-4 toxicity. No significant correlation was observed between toxicity and survival. Conclusions: Data from Italian EAP confirmed in a real-word setting the survival benefit of tebentafusp in metastatic uveal melanoma. The efficacy was observed particularly in previously untreated patients. Subjects who obtained a disease control had a longer survival. The addition of a locoregional treatment to tebentafusp could improve the clinical outcome. Clinical trial information: 543 .