Adults living with certain forms of advanced anal cancer in the UK now have access to a new treatment option after the Medicines and Healthcare products Regulatory Agency (MHRA) approved retifanlimab, marketed under the brand name ZYNYZ, for use alongside chemotherapy.
The approval, granted on 5 November 2026, covers adults with squamous cell carcinoma of the anal canal (SCAC), a type of cancer that affects the tissue lining the anal canal. It applies to patients whose cancer cannot be removed through surgery, has spread to other parts of the body or has returned in the same area following previous treatment.
The decision introduces another treatment option for people facing an advanced form of the disease, particularly where surgery is not possible or the cancer has progressed beyond its original location.
Retifanlimab is an immunotherapy medicine designed to help the body’s immune system recognise and attack cancer cells. It will be used in combination with two chemotherapy medicines, carboplatin and paclitaxel, as part of the approved treatment approach.
The MHRA said the medicine had undergone regulatory assessment before approval and that its safety and effectiveness would continue to be monitored as it becomes more widely used.
How retifanlimab works against anal cancer
Retifanlimab belongs to a group of medicines known as immune checkpoint inhibitors. These treatments work by targeting mechanisms that cancer cells can use to avoid detection by the body’s natural immune defences.
In particular, retifanlimab blocks the PD-1 pathway, which can allow certain cancer cells to evade the immune system. By blocking this pathway, the medicine helps immune cells recognise and attack cancer cells more effectively.
Unlike conventional chemotherapy, which directly targets rapidly dividing cells, immunotherapy works by helping the body’s immune system respond to cancer. Combining retifanlimab with carboplatin and paclitaxel provides a treatment approach that uses both immunotherapy and chemotherapy.
According to the MHRA, retifanlimab is administered through an intravenous infusion, which involves delivering the medicine directly into a vein. Each infusion takes approximately 30 minutes and is given once every four weeks.
During the first six treatment cycles, patients receive retifanlimab alongside carboplatin and paclitaxel. The precise treatment plan and subsequent management will depend on the patient’s clinical circumstances and the advice of their cancer specialist.
Clinical study shows improvement in time before cancer worsens
The approval was supported by a clinical study involving 308 people with metastatic or locally advanced squamous cell carcinoma of the anal canal.
Researchers compared retifanlimab given alongside chemotherapy with a placebo given alongside the same chemotherapy combination. The results showed that adding retifanlimab was more effective at increasing the length of time patients lived without their cancer getting worse.
This measure is known as progression-free survival. It is an important measure in cancer research because it helps assess how effectively a treatment can delay the progression of a disease.
The findings provided evidence supporting the medicine’s use in the specified patient group. However, treatment response can vary between individuals, and the results should not be interpreted as a guarantee that the cancer will stop progressing or that every patient will benefit.
The MHRA approval allows the medicine to be used for the specified indication in the UK, subject to its authorised prescribing information.
MHRA says new approval offers another option for patients
Julian Beach, Executive Director of Operations at the MHRA, said the regulator recognised the need for treatments that had been carefully assessed for people living with advanced anal cancer.
He said the approval provided another treatment option for adults whose cancer could not be removed through surgery, had spread to other parts of the body or had returned in the original area.
Beach also emphasised that the regulator would continue monitoring the safety and effectiveness of retifanlimab as more patients receive the medicine.
The approval follows an earlier MHRA decision on 6 July 2026, when retifanlimab was authorised for adults with advanced Merkel cell carcinoma, a rare and aggressive type of skin cancer.
The medicine is therefore authorised in the UK for more than one cancer indication, although the approved treatment combinations and eligibility requirements differ depending on the condition being treated.
What are the possible side effects?
As with other cancer medicines, retifanlimab can cause side effects, and patients need to be monitored throughout treatment.
Because it affects the immune system, immunotherapy medicines can sometimes cause the immune system to attack healthy organs and tissues. These reactions can affect different parts of the body and may require medical assessment and treatment.
The full list of reported side effects, including their frequency and severity, is provided in the medicine’s Patient Information Leaflet and Summary of Product Characteristics.
Patients should discuss possible risks, expected benefits and warning signs with their oncology team before starting treatment. Anyone receiving retifanlimab who develops new or unusual symptoms should contact their treating healthcare team promptly rather than assuming the symptoms are unrelated to treatment.
The MHRA said the relevant product information would be published on its Products website within seven days of the approval.
What the approval means for people with anal cancer in the UK
The approval represents an additional development in the treatment of advanced anal cancer, offering eligible adults another option that combines immunotherapy with established chemotherapy medicines.
However, it does not mean that retifanlimab is appropriate for everyone diagnosed with anal cancer. Its authorised use is specifically for adults with the relevant type and stage of squamous cell carcinoma of the anal canal. A specialist cancer team will determine whether the treatment is suitable after considering the diagnosis, previous treatment, overall health and other clinical factors.
The approval also should not be confused with an automatic guarantee of NHS availability or immediate access at every hospital. Regulatory approval and decisions about NHS commissioning, funding and local treatment pathways are separate processes.
For patients and families, the next step is to discuss the new treatment with an oncologist or specialist cancer team and establish whether it is available and appropriate for their individual circumstances.
Why this cancer treatment news matters to Nigerians and African communities in the UK
For Nigerians and other African communities living in Britain, developments in cancer treatment are important because access to reliable health information can influence how individuals recognise symptoms, seek medical attention and navigate conversations with healthcare professionals.
Anal cancer is an area where embarrassment and stigma can sometimes prevent people from discussing symptoms openly or seeking medical advice promptly. Changes in bowel habits, unexplained bleeding, pain or other persistent symptoms should not automatically be ignored or attributed to minor conditions. Anyone experiencing concerning symptoms should contact their GP for an appropriate assessment.
For Nigerians navigating the NHS, understanding the difference between a new medicine receiving MHRA approval and becoming routinely available through NHS treatment pathways is also important. Families should feel able to ask their GP or cancer specialist about treatment options, eligibility, possible side effects and whether newer medicines are accessible through their local NHS services.
At Chijos News, we believe that important medical developments should be explained in a way that helps diaspora families make informed decisions rather than relying on rumours, social media claims or incomplete health information. This latest approval is particularly relevant to anyone supporting a relative through cancer diagnosis or treatment, because knowing which questions to ask and where to seek specialist guidance can make the healthcare journey easier to navigate. No one should allow cultural stigma or fear of discussing an intimate health concern to stand in the way of seeking medical attention. Reliable information, early conversations with healthcare professionals and access to appropriate specialist care remain essential.
