Merck, known as MSD outside the United States and Canada, announced distant metastasis-free survival (DMFS) results from the Phase 3 KEYNOTE-716 trial investigating KEYTRUDA, Merck’s anti-PD-1 therapy, versus placebo as adjuvant therapy for patients with resected stage IIB or IIC melanoma.

With a median follow-up of 27.4 months, KEYTRUDA demonstrated a statistically significant and clinically meaningful improvement in DMFS versus placebo (HR=0.64 [95% CI, 0.47-0.88]; p=0.0029). Median DMFS was not reached in either arm.

Additionally, at the median 27.4-month follow-up, KEYTRUDA continued to show a reduction in the risk of recurrence versus placebo (HR=0.64 [95% CI, 0.50-0.84]).

“Patients with stage IIB and IIC melanoma are at risk of seeing their cancer return and spread to distant sites,” said Dr. Georgina Long, co-medical director, Melanoma Institute Australia (MIA), and chair, Melanoma Medical Oncology and Translational Research at MIA and Royal North Shore Hospital, University of Sydney.

“The latest results from KEYNOTE-716 show the potential of pembrolizumab to help reduce distant recurrence in patients with resected stage IIB and IIC melanoma, and further highlight the important role of adjuvant therapy for these patients.”

In the study, the safety profile of KEYTRUDA was consistent with previously reported studies in patients with solid tumors, and no new safety signals were observed at the time of DMFS analysis. Treatment-related adverse events Grade 3 or higher were observed in 17% of patients receiving KEYTRUDA versus 5% of patients receiving placebo. Immune-mediated events and infusion reactions were higher with KEYTRUDA (38% vs 9%, respectively).

“Based on survival data, we know that patients with stage IIB and IIC melanoma have similar five-year outcomes as those with stage IIIB melanoma,” said Dr. Scot Ebbinghaus, vice president, global clinical development, Merck Research Laboratories. “In KEYNOTE-716, treatment with KEYTRUDA after surgery improved both distant metastasis-free survival and recurrence-free survivalcompared to placebo in patients with stage IIB or IIC melanoma. These data are encouraging for the melanoma community and add to results from six positive pivotal studies for KEYTRUDA-based regimens in earlier stages of cancer.”

In addition to KEYNOTE-716, the five other pivotal trials evaluating a KEYTRUDA-based regimen in patients with earlier stages of cancer met their primary endpoint(s). These trials include: KEYNOTE-091 in stage IB (≥4 centimeters) to IIIA non-small cell lung cancer; KEYNOTE-054 in stage III melanoma; KEYNOTE-564 in renal cell carcinoma; KEYNOTE-522 in triple-negative breast cancer; and KEYNOTE-057 in Bacillus Calmette-Guerin (BCG)-unresponsive, high-risk, non-muscle invasive bladder cancer.