A total of 834 patients were included in the trial and were given Keytruda 10mg/kg every three weeks, Keytruda 10mg/kg every two weeks, or four cycles of ipilimumab 3mg/kg every three weeks.
The company said that the randomized, pivotal Phase III trial met its two primary endpoints of progression-free survival (PFS) and overall survival (OS).
Based on the recommendation of the trial’s independent Data Monitoring Committee, the company will stop the trial early.
In the trial, Keytruda, a humanized monoclonal antibody, showed a statistically significant and clinically meaningful improvement in OS and PFS compared to ipilimumab.
The safety profile of Keytruda was similar to the safety profile previously reported in advanced melanoma.
Keytruda is claimed to be the first anti-programmed death receptor-1 (PD-1) therapy to show a survival advantage compared to the standard of care for the first-line treatment of advanced melanoma.
Merck Research Laboratories president Dr Roger Perlmutter said: "Evidence from our clinical program for Keytruda will help to define the appropriate treatment of advanced melanoma.
"We greatly appreciate the efforts of our investigators and their patients in this important study, and we look forward to the presentation of overall survival data from KEYNOTE-006 at the AACR annual meeting."
Keytruda blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2.
In the US, Keytruda is indicated at a dose of 2mg/kg administered as an intravenous infusion over 30 minutes every three weeks to treat patients with unresectable or metastatic melanoma and disease progression following ipilimumab and, if BRAF V600 mutation positive, a BRAF inhibitor.
Image: Keytruda is indicated at a dose of 2mg/kg administered as an intravenous infusion in the US. Photo: courtesy of Baitong333/ freedigitalphotos.net.