Perioperative Pembrolizumab in Locally Advanced Melanoma: A Real-world Single-centre Retrospective Study.

Perioperative immune-checkpoint inhibition (ICI) using pembrolizumab (3 doses of pembrolizumab 200 mg every 3 weeks before surgery and 15 doses afterwards) in advanced resectable melanoma has shown substantial pathological response rates and improved event-free survival (EFS) compared to postoperative (adjuvant) ICI. Real-world evidence on efficacy and safety of perioperative ICI in melanoma remains limited. In this retrospective single-centre study, 20 patients with resectable stage IIIB–IV melanoma were treated with perioperative pembrolizumab. Radiological and pathological responses, early survival outcomes and treatment-related adverse events were analysed at a median follow-up of 13.9 months. Eighteen patients (18/20) underwent surgery. A pathological complete response was observed in 44% (8/18), while 56% (10/18) showed a pathological non-response. No patient (0/18) had a pathological partial response. One-year EFS was 66.5% (95% confidence interval (CI) 47.3-93.3), 1-year relapse-free survival 77.6% (95% CI 57.9-100) and 1-year overall survival 89.2% (95% CI 76.0-100, identical with 1-year melanoma-specific survival). Immune-related adverse events occurred in 50% of the patients (≥grade 3 in 15%). Our study confirms the feasibility of perioperative pembrolizumab in a real-world setting and shows promising efficacy and tolerability in melanoma. Pathological response may guide surgical and adjuvant strategies.