Adults in the UK with squamous cell carcinoma of the anal canal (SCAC) that surgeons cannot remove now have a newly licensed medicine. The Medicines and Healthcare products Regulatory Agency (MHRA) has authorised retifanlimab, branded ZYNYZ, for patients whose tumour is metastatic or has recurred in the area where it first appeared. It is given together with the chemotherapy drugs carboplatin and paclitaxel. According to the regulator, the licence was issued to Incyte Biosciences UK Ltd on 5 November 2026.
Trial evidence
The MHRA cited a study of 308 patients whose SCAC was metastatic or locally advanced. Those who received retifanlimab plus chemotherapy went longer before their disease worsened than those who received chemotherapy with a placebo, the agency said.
How the drug works and is given
Retifanlimab acts on the immune system, according to the MHRA. Tumours can exploit a particular pathway to escape notice by the body's defences, and the drug shuts that route off, leaving immune cells better able to recognise and kill cancer cells.
Patients receive it as an intravenous drip lasting about 30 minutes every four weeks. Carboplatin and paclitaxel are added for the first six cycles.
The regulator's position
Julian Beach, the MHRA's Executive Director, Operations, said: "People living with advanced anal cancer need treatments that have been carefully assessed." He added that the decision offers adults with inoperable, spreading or recurring disease another option, and that the agency will keep tracking the medicine's safety and effectiveness as more patients are treated with it.
A second UK licence
This is not the drug's first authorisation in Britain. On 6 July 2026 the MHRA cleared retifanlimab for adults with advanced Merkel cell carcinoma, which the agency describes as a rare, aggressive skin cancer. The anal cancer application went through the International Recognition Procedure (IRP), the regulator said.
According to the MHRA, the Summary of Product Characteristics (SmPC) and the Patient Information Leaflet (PIL) are due on its Products website within 7 days of approval. Reported side effects are listed in full in Section 4 of the PIL or in the SmPC.
