Adjuvant Systemic Immunotherapies for Resected Stage III Melanoma: A Single-Centre Retrospective Clinical Practice...

Melanoma poses significant challenges due to its resistance to conventional therapies and increasing incidence rates. Stage III melanoma, characterised by regional lymph node involvement, has a high risk of recurrence despite surgical resection. Adjuvant immunotherapy, particularly using the PD-1 inhibitors pembrolizumab and nivolumab, has shown promising results in improving recurrence-free survival (RFS) and overall survival (OS) in Stage III melanoma patients. This retrospective analysis examined the effects of adjuvant pembrolizumab or nivolumab on patients with Stage III melanoma treated in a tertiary oncology centre. Of the 110 patients, 95 received pembrolizumab and 15 received nivolumab. The pembrolizumab completion rate was 62.1%, with 31.2% discontinuing due to disease progression or adverse effects. The nivolumab completion rate was lower at 40%, with 60% discontinuing due to toxicity or disease progression. Grade 3 or higher toxicities were observed in 17% of pembrolizumab and 53.3% of nivolumab patients. Disease progression occurred in 27.4% of pembrolizumab and 26.7% of nivolumab patients. Pembrolizumab showed a 12-month RFS of 78.9% and 24-month RFS of 77.6%, with an OS of 97.9% at 12 months. Nivolumab exhibited a 12-month RFS of 86.7% and 24-month RFS of 80%. RFS rates varied by disease stage and mutation status. Adjuvant pembrolizumab and nivolumab both demonstrate efficacy in improving RFS and OS in Stage III melanoma patients. Pembrolizumab has higher completion rates and fewer toxicities compared to nivolumab. Further studies are warranted to explore long-term outcomes and optimise treatment strategies.