The study details
KEYNOTE-716 included 976 patients 12 years or older with newly diagnosed completely resected stage IIB or IIC melanoma with a negative sentinel lymph node. Patients were randomized to placebo or 200 mg pembrolizumab every 3 weeks, or 2 mg/kg in pediatric patients, over 17 cycles. Almost 40% of patients were age 65 or older. T3b and T4b were the most common melanoma subcategories at 41% and 35%, respectively.
The planned third interim analysis occurred after the occurrence of 146 distant metastases. After a median follow-up of 27.4 months, distant metastasis-free survival favored the pembrolizumab group (HR, 0.64; P = .0029). At 24 months, the pembrolizumab group had a higher distant metastasis-free survival at 88.1% versus 82.2% and a lower recurrence rate at 81.2% versus 72.8% (HR, 0.64; 95% confidence interval, 0.50-0.84).
At 24 months, only the T4a patients had a statistically significant reduction in distant metastases at 58% (HR, 0.42; 95% CI, 0.19-0.96), although there were numerical reductions in T3a (HR, 0.71; 95% CI, 0.41-1.22) and T4b (HR, 0.70; 95% CI, 0.44-1.33) patients. Of patients experiencing a distant metastasis, 73% of the placebo group had a first distant metastasis to the lung compared with 49% of the pembrolizumab group.
Dr. Long has held consulting or advisory roles for Merck Sharpe & Dohme, which funded this study.
