Merck & Co – known as MSD outside the US and Canada – has shared positive ten-year results from a late-stage study of its anti-PD-1 therapy Keytruda (pembrolizumab) in melanoma.

The open-label KEYNOTE-006 trial has been evaluating the drug against Bristol Myers Squibb’s Yervoy (ipilimumab) in patients with advanced cases of the skin cancer.

The incidence of melanoma has been rising steadily over the past few decades, with more than 100,640 people expected to be diagnosed with the disease in the US this year.

Keytruda works by increasing the ability of the body’s immune system to help detect and fight tumour cells, and is already authorised to treat certain cases of melanoma, including patients with unresectable or metastatic disease, and those with stages 2B, 2C or 3 disease following complete resection.

The results, presented at this year’s European Society for Medical Oncology Congress and published in the Annals of Oncology, showed “sustained improved survival outcomes” for patients receiving Keytruda as a single agent compared to Yervoy, Merck said.

The ten-year overall survival (OS) rate for Keytruda was 34% compared to 23.6% for Yervoy. Merck’s drug was also shown to reduce the risk of death by 29%, and more than doubled median OS compared to Yervoy, at 32.7 months versus 15.9 months.

Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories, said: “Ten years ago, Keytruda became the first anti-PD-1/L1 therapy approved in the US, setting the stage for transformative breakthroughs in the treatment of advanced melanoma and other types of cancer.

“Keytruda has reshaped the treatment of certain types of cancers, extending its benefits to a broader range of tumour types and patients, and we look forward to the prospect of more innovation for patients over the next ten years and beyond.”