[Real-world outcomes of avelumab treatment for Merkel cell carcinoma : An Austrian multicenter real-world study].

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine skin cancer. Treatment with avelumab (Programmed Death-Ligand 1 (PD-L1) antibody) is established in advanced disease, but real-world data are limited.

OBJECTIVE

To assess effectiveness and safety of avelumab for advanced MCC in Austria.

MATERIALS AND

METHODS

This multicenter retrospective chart-review study included 49 patients with Merkel cell carcinoma who had received at least one cycle of avelumab between September 2017 and December 2023. The primary endpoint was real-world progression-free survival (rwPFS). Secondary endpoints included real-world overall survival (rwOS), real-world objective response rate (rwORR), real-world duration of response (rwDOR), real-world time to response (rwTTR), and safety; real-world time to treatment discontinuation (rwTTD) univariable subgroup analyses and post hoc multivariable Cox regression models were assessed exploratorily.

RESULTS

Median rwPFS was 10.1 months (95% CI 1.8-18.4), and median rwOS was 22.9 months (95% CI 5.0-40.8). RwORR was 47.9% (95% CI 34.5-61.7), and median rwDOR was 19.2 months. Adverse events (AEs) occurred in 71.4% of patients and were grade ≥ 3 in 48.6% of affected patients. Immune- and/or treatment-related AEs were documented in 53.1%; 12.2% discontinued treatment due to adverse events.

CONCLUSION

Real-world data support avelumab effectiveness with an expected safety profile in advanced MCC. In routine care, AEs may limit treatment duration, underscoring structured monitoring and interdisciplinary management.