The following article features coverage from the European Society of Medical Oncology (ESMO) Congress 2021. Click here to read more of MPR‘s conference coverage.

Adjuvant pembrolizumab prolongs relapse-free survival (RFS), when compared with placebo, in patients with resected, stage II melanoma, according to results of the phase 3 KEYNOTE-716 trial.

These results were presented at the European Society for Medical Oncology (ESMO) Congress 2021 by Jason J. Luke, MD, of the UPMC Hillman Cancer Center in Pittsburgh, Pennsylvania. The double-blind, phase 3 KEYNOTE-716 trial (ClinicalTrials.gov Identifier: NCT03553836) included 976 patients, age 12 or older, who had newly diagnosed, resected, cutaneous stage IIB or IIC melanoma with negative sentinel lymph node biopsies.


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Patients were randomly assigned to receive pembrolizumab or placebo after resection. Part 2 of the trial involves a rechallenge or crossover, in which patients with a recurrence receive pembrolizumab for up to 2 years. The results of part 2 are not yet mature.

Dr Luke presented results from part 1, with a median follow-up of 14.4 months in the pembrolizumab arm (487 patients) and 14.3 months in the placebo arm (489 patients). At baseline, the median age was 60 years in the pembrolizumab arm and 61 years in the placebo arm (overall range, 16-87 years). There was 1 pediatric patient (12-17 years) in each arm.

Most patients in each arm had stage IIB disease, 63.4% in the pembrolizumab arm and 64.6% in the placebo arm, and most were male, 61.6% and 59.1%, respectively.

Pembrolizumab significantly prolonged RFS, though the median RFS was not reached in either treatment arm. The 12-month RFS rate was 90.5% with pembrolizumab and 83.1% with placebo (hazard ratio [HR], 0.65; 95% CI, 0.46-0.92; P =.00658).

The rate of recurrence was 11.1% in the pembrolizumab arm and 16.8% in the placebo arm. The rate of distant recurrence was 4.7% and 7.8%, respectively. “Global health status quality of life scores were similar between the treatment groups at all time points,” Dr Luke said. Treatment-related adverse events (TRAEs) of grade 3-4 were more common in the pembrolizumab arm than in the placebo arm — 16.1% and 4.3%, respectively. Discontinuation due to a TRAE occurred in 15.3% and 2.5% of patients, respectively. There were no fatal TRAEs in either arm.

The most common immune-related events in the pembrolizumab arm were hypothyroidism and hyperthyroidism, which were primarily grade 1 or 2 in severity. “Adjuvant pembrolizumab is an effective treatment option with a favorable benefit-risk profile for patients with high-risk, stage II melanoma,” Dr Luke said.

Disclosures: This research was supported by Merck Sharp & Dohme Corp. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Luke JJ, Rutkowski P, Queirolo P, et al. Pembrolizumab versus placebo after complete resection of high-risk stage II melanoma: Efficacy and safety results from the KEYNOTE-716 double-blind phase III trial. Presented at: European Society for Medical Oncology (ESMO) Congress 2021; September 16-21, 2021. Abstract LBA3_PR.

This article originally appeared on Cancer Therapy Advisor