Pembrolizumab is marketed in the US under the name Keytruda.
EAMS was introduced by the UK Medicines and Healthcare Products Regulatory Agency (MHRA) in 2014 to help patients benefit from promising, new treatments before a European licence has been granted.
The EAMS acceptance of pembrolizumab was based on review of data for pembrolizumab from KEYNOTE-001, the largest Phase Ib trial of an anti-PD-1 therapy in patients with advanced melanoma.
In October 2014, pembrolizumab received the promising innovative medicine (PIM) designation in the UK.
Under the scheme, the UK Medicines and Healthcare products Regulatory Agency (MHRA) will give a scientific opinion on the benefit/risk balance of the medicine, based on the data available when the EAMS submission was made.
Currently, marketing authorization for pembrolizumab in Europe is under review for the treatment of advanced melanoma.
Merck Research Laboratories president Dr Roger Perlmutter said: "Merck has charted a path to accelerate the development of pembrolizumab, and is collaborating with governments around the world to bring our anti-PD-1 therapy to cancer patients.
"This acceptance of pembrolizumab into the Scheme will enable many patients in the UK with advanced melanoma to gain earlier access to pembrolizumab, and underscores the importance of creating new mechanisms to bring promising medicines to patients for whom there are limited options."
Based on the same data from the Phase Ib KEYNOTE-001 trial, pembrolizumab was granted breakthrough therapy designation for advanced melanoma by the US Food and Drug Administration in September 2014.