Adjuvant Use of Pembrolizumab for Stage III Melanoma in a Real-World Setting in Europe

Background: Although data on patients treated with pembrolizumab are available from clinical trials and single-country real-world reports, to our knowledge no multi-country real-world studies have investigated the use of pembrolizumab as an adjuvant treatment for stage III melanoma. Methods: We used the European Melanoma Registry (EUMelaReg), a disease entity-based registry specific for melanoma, to examine treatment and outcomes for adult patients with stage III melanoma with lymph node involvement who had complete resection and received adjuvant treatment with pembrolizumab. The primary objectives were to describe the demographic and clinical characteristics of the included patients as well as time on adjuvant pembrolizumab treatment (TOT), real-world recurrence-free survival (RFS) and distant metastasis-free survival (DMFS) from adjuvant pembrolizumab initiation. Secondary objectives were time to next treatment (TTNT) after adjuvant use of pembrolizumab, next-line therapy for stage III and unresectable stage IV melanoma and overall survival (OS) from initiation of pembrolizumab. Results: Patients were stratified according to age, sex, BRAF status, number of positive lymph nodes and disease substage. Median TOT was 11.1 (9.2-11.5) months, median RFS was 29.6 [18.7-not reached (NR)] months and median DMFS was 32.4 (22.7-NR) months. TTNT was 29.9 (22.2-NR) months, while median OS was not reached. Conclusions: The results of this study offer insights into the real-world use of pembrolizumab as an adjuvant therapy for melanoma in Europe.