The UK MHRA has approved Incyte’s retifanlimab (ZYNYZ) as the first first-line treatment for adults with advanced Merkel cell carcinoma, supported by Phase 2 POD1UM-201 trial data demonstrating durable clinical responses.
Written By: Meghana Jinka, PharmD
Reviewed By: Pharmacally Editorial Team
The UK Medicines and Healthcare products Regulatory Agency (MHRA) has approved retifanlimab (ZYNYZ) for the first-line treatment of adults with advanced Merkel cell carcinoma (MCC) whose disease has spread or recurred and cannot be cured with surgery or radiotherapy. Granted to Incyte Biosciences UK Ltd on July 6, 2026, the approval establishes retifanlimab as the first licensed initial systemic therapy for this patient population in the UK. The medicine was reviewed through the MHRA’s International Recognition Procedure (IRP).
Addressing an Unmet Need in Advanced MCC
Merkel cell carcinoma is a rare, aggressive neuroendocrine skin cancer that arises from Merkel cells in the epidermis. Although uncommon, it progresses rapidly, frequently metastasizes, and carries a poor prognosis in advanced stages. The approval provides the first dedicated first-line treatment option for patients whose disease is no longer amenable to curative local therapies.
Retifanlimab is a humanized monoclonal antibody that blocks the programmed death receptor-1 (PD-1) immune checkpoint, restoring T-cell activity against cancer cells. The therapy is administered as a diluted intravenous infusion over approximately 30 minutes.
Clinical Study Demonstrated Durable Responses
The approval was supported by a clinical study (POD1UM-201, NCT03599713) involving 101 adults with advanced Merkel cell carcinoma who had not previously received systemic treatment for advanced disease.
Retifanlimab achieved an objective response rate of 53.5%, including complete responses in 16.8% of patients and partial responses in 36.6%. Among responders, the median duration of response exceeded two years, demonstrating durable disease control in a cancer with historically limited treatment options.
The MHRA did not report new safety concerns as part of the approval. Full prescribing information, including adverse reactions, will be available in the Summary of Product Characteristics (SmPC) and Patient Information Leaflet (PIL), which are expected to be published on the MHRA Products website within seven days.
Regulatory Perspective and Outlook
Commenting on the approval, Julian Beach, Executive Director of Healthcare Quality and Access at the MHRA, said the decision provides the first treatment option for adults with advanced Merkel cell carcinoma that has spread or returned and cannot be treated with surgery or radiotherapy. He added that the agency will continue to closely monitor the medicine’s safety and effectiveness as its clinical use expands.
The approval marks an important advance for patients with advanced MCC in the UK by introducing an approved first-line immunotherapy for this rare malignancy. With durable responses observed in more than half of previously untreated patients, retifanlimab expands the therapeutic landscape and offers clinicians a new evidence-based option while ongoing pharmacovigilance continues to evaluate its long-term safety and real-world effectiveness.
Reference
MHRA approves Retifanlimab (ZYNYZ) for the treatment of advanced Merkel cell skin cancer – GOV.UK
About the Writer
Meghana Jinka (LinkedIn) is a Pharm.D graduate with a strong interest in clinical pharmacy, clinical research, pharmacovigilance, and medical writing. She has developed expertise in evaluating scientific literature, interpreting clinical data, and communicating complex medical information in a clear and accessible manner. Through clinical training, patient counseling, and healthcare awareness activities, she has gained practical experience in evidence-based medicine and patient-centered care. Passionate about healthcare communication, Meghana is committed to developing accurate, engaging, and evidence-based healthcare documents that support healthcare professionals and the wider community.