The Food and Drug Administration (FDA) has approved pembrolizumab for the adjuvant treatment of patients with melanoma with involvement of lymph node(s) following complete resection.
Approval was based on EORTC1325/KEYNOTE‑054 (NCT02362594), a randomised, double-blind, placebo-controlled, trial in 1019 patients with completely resected, stage IIIA (>1 mm lymph node metastasis), IIIB or IIIC melanoma.
Patients with mucosal or ocular melanoma were not eligible.
Patients were randomly allocated (1:1) to receive pembrolizumab 200 mg every three weeks or placebo for up to 1 year until disease recurrence or unacceptable toxicity.
Enrollment required complete resection of melanoma with negative margins, lymph node dissection and completion of radiotherapy, if indicated, within 13 weeks prior to starting treatment.
The primary efficacy outcome measure was recurrence‑free survival (RFS), as assessed by investigators per RECIST version 1.1.
RFS was defined as the time between the date of randomisation and first recurrence (local, regional, or distant metastasis) or death from any cause, whichever occurred first.
Patients receiving pembrolizumab experienced fewer recurrences/deaths, 26% (n=135), compared with 43% (n=216) on the placebo arm (hazard ratio 0.57; 95% CI: 0.46, 0.70; p<0.001).
The RFS benefit for pembrolizumab compared with placebo was observed regardless of tumour PD-L1 expression.
Median RFS was 20.4 months in the placebo arm and not reached for those receiving pembrolizumab.
Seventy-six percent of patients received pembrolizumab for 6 months or longer.
Pembrolizumab was discontinued for adverse reactions in 14% of patients.
The most common adverse reactions (reported in at least 10% of pembrolizumab-treated patients) were diarrhoea, pruritus, nausea, arthralgia, hypothyroidism, cough, rash, asthenia, influenza-like illness, weight loss, and hyperthyroidism.
The recommended pembrolizumab dose and schedule for the adjuvant treatment of melanoma is 200 mg administered as an IV infusion over 30 minutes every 3 weeks until disease recurrence or unacceptable toxicity, for a maximum of 1 year.