Merck & Co’s anti-PD-1 therapy Keytruda has been approved in Europe for the treatment of advanced skin cancer.

The closely-watched immunotherapy won backing from the European Commission after trials showed it offered a superior survival benefit as a monotherapy compared to Bristol-Myers Squibb’s Yervoy (ipilimumab), the current standard of care.

According to data from the Phase III KEYNOTE-006 study, one-year survival for Keytruda (pembrolizumab; dosed every two weeks) was 74% versus 58% for Yervoy, while the risk of death was cut by 37%, the drugmaker said.

On the safety side, the most common adverse reactions (>10%) linked with Merck’s drug were diarrhoea (15%), nausea (12%), pruritus (25%), rash (25%), arthralgia (13%) and fatigue (33%) and generally mild in nature; the most serious were immune-related adverse reactions and severe infusion-related reactions.

Keytruda will compete for market share with BMS’ Opdivo (nivolumab), the first PD-1 inhibitor to bag European approval when it was cleared for advanced melanoma last month.