MHRA approves Retifanlimab (ZYNYZ) for the treatment of advanced Merkel cell skin cancer

MHRA approves Retifanlimab (ZYNYZ) for the treatment of advanced Merkel cell skin cancer
Merkel cell carcinoma (MCC) is a rare and aggressive type of skin cancer that develops from Merkel cells, specialised neuroendocrine cells found in the top layer of the skin.
The Medicines and Healthcare products Regulatory Agency (MHRA) has today (6 July 2026) approved Retifanlimab (ZYNYZ) as the first treatment given to adults with advanced Merkel cell skin cancer that has spread or returned and cannot be cured with an operation or radiotherapy.
Merkel cell carcinoma (MCC) is a rare and aggressive type of skin cancer that develops from Merkel cells, specialised neuroendocrine cells found in the top layer of the skin.
Retifanlimab works by helping the body’s immune system recognise and attack cancer cells. It blocks a pathway that cancer cells can use to avoid being detected by the immune system, allowing immune cells to better identify and destroy them.
Retifanlimab is administered via diluted intravenous infusion over 30 minutes.
In a study of 101 adults with advanced Merkel cell carcinoma who had not previously received treatment for their advanced disease, 53.5% of patients responded to treatment with Retifanlimab. Of these, 16.8% had no detectable signs of cancer after treatment, while 36.6% experienced tumour shrinkage. Among patients who responded to treatment, the response typically lasted just over two years.
Julian Beach, MHRA Executive Director of Healthcare Quality and Access, said:
“This approval provides the first treatment option for adults with advanced Merkel cell carcinoma that has spread or returned and cannot be cured with surgery or radiotherapy.
“As with all medicines, we will continue to closely monitor the safety and effectiveness of retifanlimab as it is used more widely.”
For the full list of all side effects reported with this medicine, see Section 4 of the PIL or the SmPC available on the MHRA website.
Notes to editors
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The approval was granted on 6 July 2026 to Incyte Biosciences UK Ltd
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This product was submitted and approved via International Recognition Procedure (IRP).
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More information can be found in the Summary of Product Characteristics and Patient Information Leaflets which will be published on the MHRA Products website within 7 days of approval.
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The Medicines and Healthcare products Regulatory Agency (MHRA) is responsible for regulating all medicines and medical devices in the UK by ensuring they work and are acceptably safe. All our work is underpinned by robust and fact-based judgements to ensure that the benefits justify any risks.
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The MHRA is an executive agency of the Department of Health and Social Care.
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For media enquiries, please contact newscentre@mhra.gov.uk or call 020 3080 7651.