Merck has received approval from the US Food and Drug Administration (FDA) for its Keytruda (pembrolizumab) at a dose of 2mg/kg 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.

Approval was based on data from a multi-centre, open-label, randomised, dose-comparative study cohort of the ongoing Keynote-001 Phase Ib trial in patients with unresectable or metastatic melanoma and progression of disease.

Keytruda is a humanised monoclonal antibody that increases the ability of the body’s immune system. It interacts between PD-1 and its ligands, PD-L1 and PD-L2 and may affect tumour cells and healthy cells.

Merck chairman and CEO Kenneth Frazier said: "Keytruda embodies Merck’s unwavering commitment to pursue breakthrough science to help people who are facing the most challenging diseases.

"Involving 89 patients, the study showed the response rate of 24%."

"We are grateful to the people with advanced melanoma who participated in our trials, and the scientific and medical community for the shared effort that has led to the accelerated approval of Keytruda."

Merck noted that Keytruda is the first anti-programmed death receptor-1 (PD-1) therapy approved in the US and received FDA’s breakthrough therapy designation for advanced melanoma, based on the significance of early study findings and the unmet medical need.

Involving 89 patients, the study showed the response rate of 24%, with one complete response and 20 partial responses for the recommended 2mg/kg dose.

The company also started Phase II and III clinical studies in advanced melanoma, in order to provide further confirmatory evidence for Keytruda in this indication.

Image: Merck’s Keytruda (pembrolizumab) for Injection. Photo: Copyright © 2009-2014 Merck Sharp & Dohme Corp, a subsidiary of Merck & Co, Inc, Whitehouse Station, New Jersey, US.