Adjuvant Pembrolizumab Continues to Prolong Survival Outcomes Among Patients With Stage IIB/IIC Melanoma

According to long-term follow-up results from the KEYNOTE-716 trial, adjuvant pembrolizumab continued to prolong recurrence-free and distant metastasis-free survivals among patients with stage IIB/IIC melanoma. 

In this study, 976 patients were randomized on a 1-to-1 basis to receive either 200 mg of intravenous pembrolizumab or placebo once every 3 weeks. Patients who experienced disease progression either crossed over or received pembrolizumab rechallenge. The primary end point was recurrence-free survival (RFS). Key secondary end points included distant metastasis-free survival (DMFS) and progression/recurrence-free survival 2 (PRFS2). 

At a median follow-up of 52.8 months, the 48-month RFS rate was 71.3% in the pembrolizumab arm and 58.3% in the placebo arm. The DMFS rates were 81% and 70.1%, respectively. The 48-month PRFS2 rate was 82.5% in the pembrolizumab arm and 76.7% in the placebo arm. Among patients who crossed over from placebo to pembrolizumab, median RFS was not reached for patients with resectable disease (n = 41). For patients with unresectable disease (n = 30), the median progression-free survival rate was 22 months. Among patients who underwent pembrolizumab rechallenge, patients with resectable disease (n =6) did not experience recurrence and 1 patient with unresectable disease (n = 3) had a best response of stable disease. Safety was consistent with prior findings.

“With > 4 years follow-up, pembrolizumab continued to prolong RFS and DMFS and had antitumor activity in patients who crossed over to pembrolizumab,” concluded Dr Luke et al. 

Source: 

Luke JJ, Ascierto PA, Khattak MA, et al. Pembrolizumab versus placebo as adjuvant therapy in resected stage IIB or IIC melanoma: Long-term follow-up, crossover, and rechallenge with pembrolizumab in the phase III KEYNOTE-716 study. Eur J Cancer. Published online: March 23, 2025. doi: 10.1016/j.ejca.2025.115381