The UK Medicines and Healthcare products Regulatory Agency (MHRA) has approved retifanlimab (Zynyz), developed by Incyte Biosciences UK, for treating adults with Squamous Cell Carcinoma of the Anal Canal (SCAC) that cannot be removed through surgery and is either metastatic or has returned locally.

The approval was granted on November 5, 2026, through the International Recognition Procedure (IRP). It expands the approved use of retifanlimab in the UK, following its earlier approval on July 6, 2026, for adults with advanced Merkel cell carcinoma, a rare and aggressive form of skin cancer.

Retifanlimab is a cancer immunotherapy administered in combination with the chemotherapy medicines carboplatin and paclitaxel. It works by blocking a pathway that cancer cells use to evade detection by the immune system, helping immune cells recognise and attack cancer cells.

The medicine is administered through an intravenous infusion lasting approximately 30 minutes, once every four weeks. During the first six treatment cycles, it is given alongside carboplatin and paclitaxel.

The approval was supported by a study involving 308 people with metastatic or locally advanced SCAC. The study found that retifanlimab, when used in combination with chemotherapy, was more effective than placebo combined with chemotherapy in extending the time patients lived without their cancer worsening.

Commenting on the approval, Julian Beach, Executive Director of Operations at the MHRA, said the decision provides a new treatment option for adults whose anal cancer cannot be surgically removed, has spread to other parts of the body or has returned in the same area. He added that the agency would continue to monitor the medicine's safety and effectiveness as its use expands.