Tebentafusp (tebe) in a real-world cohort of 72 French metastatic uveal melanoma (UM) patients (pts).

Abstract

e21583 Background: Up to 50% of UM pts will develop metastases with poor overall survival (OS) and limited treatment options. Tebe, a bispecific T-cell engager binding CD3 and the gp100 protein presented by the HLA A*02-01, recently showed a benefit in overall response rate (ORR), progression-free survival (PFS) and OS in HLA A*02-01pos metastatic UM (mUM) pts in the IMCgp100-202 phase III trial. Prior to the EMA approval, French Health Authorities allowed an early access to tebe in May 2021 to UM metastatic pts. We here report our real-world experience with tebe in metastatic UM pts. Methods: Ongoing ambispective cohort of mUM pts treated with tebe in France. Metastases are evaluated according to RECIST 1.1 with assessments every 12 weeks (liver MRI +/- CT-scan). ORR, PFS, OS and toxicities are retrieved. Results: 72 pts started tebe between May 26th 2021 and December 12th 2022 (29 men and 43 women). Median age was 61 yo (32-78). Thirty, 34 and 7 patients underwent enucleation proton beam therapy or brachytherapy, respectively (one pt did not receive local treatment). The median time to first metastasis was 24 months (0-276). Tebe was prescribed in first-line in 46 patients, in second-line or more in 26 patients. Metastatic sites at tebe initiation were liver, lung, skin, bone and muscle in 71, 4, 2, 3 and 2 patients, respectively. Liver was the sole metastatic site in 63/72 patients (87.5%). With a median follow-up of 44 weeks, patients received a median of 36 weeks of tebe. Thirty patients discontinued tebe because of disease progression, two because of poor health status and none for toxicity. Of 60 assessable pts, 33 (55%) pts showed stable disease and 5 (8%) showed partial response as best response according to RECIST 1.1. Median PFS was 28 weeks (confidence interval 95% [CI95%]: 8-56) in the global cohort. OS at 12 months was 74% ([CI95%] = 0.62-0.89) in the global cohort, 73% ([CI95%] = 0.55-0.99) and 74% ([CI95%] = 0.57-0.97) in 1st and 2nd line and more, respectively. To date, 13 pts died. Circulating tumor DNA analyses and monitoring of peripheral blood leukocytes are ongoing and will be available by June 2023. Conclusions: In this ongoing, real-world, cohort of metastatic UM pts, tebe is associated with similar clinical outcomes as in the IMCgp100-202, phase III trial. Translational studies on blood and tumor samples are ongoing to identify predictive biomarkers of clinical benefit to this drug.