Merck & Co is pulling the plug on a late-stage trial of its immunotherapy Keytruda (pembrolizumab) in patients with melanoma ahead of schedule, after the drug smashed its targets by beating Bristol-Myers Squibb’s Yervoy (ipilimumab) on survival endpoints.

An independent Data Monitoring Committee has recommended that the pivotal Phase III study (KEYNOTE-006) be halted early, as Keytruda demonstrated “a statistically significant and clinically meaningful improvement in overall survival and progression-free survival” in untreated patients compared to Yervoy.

The drug is now the first anti-PD-1 therapy to demonstrate a survival advantage compared to the standard of care for the first-line treatment of advanced melanoma, Merck noted.

Keytruda was approved by the US Food and Drug Administration in September last year for patients with advanced or unresectable melanoma who are no longer responding to other drugs; clearance in the first-line setting could significantly expand the drug’s reach.