The Medicines and Healthcare products Regulatory Agency has approved catumaxomab, marketed as Korjuny, for adults with malignant ascites when standard treatment for the underlying cancer is no longer feasible. In regulatory terms, the decision adds a licensed option for a patient group that is often managed through repeated symptom-relief procedures rather than further disease-directed treatment. Malignant ascites is a build-up of fluid in the abdomen that contains cancer cells. The condition can place a significant burden on patients and commonly requires paracentesis to drain the fluid. The MHRA said the purpose of approval is to extend the time before another drainage procedure is needed.
According to the MHRA, catumaxomab is a monoclonal antibody that recognises epithelial cell adhesion molecule, or EpCAM, on certain cancer cells, including cells present in ascitic fluid. By binding to that target, the medicine is intended to activate immune cells and support the destruction of EpCAM-positive tumour cells within the abdominal cavity. That matters because the product is being authorised for a defined clinical setting rather than as a replacement for systemic cancer treatment. For clinicians and patients, the approval concerns symptom control and the management of recurrent abdominal fluid build-up in advanced disease.
The evidence cited by the MHRA comes from a main clinical study involving 258 patients with malignant ascites and EpCAM-positive cancer who had no further chemotherapy options or for whom chemotherapy was unsuitable. Patients who received catumaxomab after paracentesis did not require further drainage for around 46 days, compared with 11 days for patients treated with paracentesis alone. On the regulator's account, that difference is the main practical effect of the medicine. A longer interval between drainage procedures may reduce the frequency of repeat interventions for some patients, although the treatment remains limited to a narrow group defined by tumour characteristics and treatment history.
The MHRA said catumaxomab must be given under the supervision of a doctor experienced in treating cancer. It is administered through a catheter directly into the abdominal cavity as four infusions, with the dose increased at each infusion. This method of administration means the approval is likely to sit within specialist oncology and supportive care pathways rather than broad routine prescribing. Access will depend on clinical suitability, the presence of EpCAM-positive disease and the capacity of treating teams to deliver the medicine safely.
Safety monitoring remains a prominent part of the approval. The MHRA listed common side effects including nausea, vomiting, diarrhoea, abdominal pain, fever, chills, fatigue and cytokine release syndrome, which it described as an inflammatory reaction caused by activation of the immune system. Julian Beach, the MHRA's Interim Executive Director of Healthcare Quality and Access, said malignant ascites can place a considerable burden on people living with cancer, particularly when treatment options are limited. He also said the agency would continue to monitor the medicine closely and encouraged reporting of suspected side effects through the Yellow Card scheme.
The agency said the marketing authorisation was granted on 2 October to Atnahs Pharma UK Limited and that the application was approved under the International Recognition Procedure. It also said the Summary of Product Characteristics and Patient Information Leaflet would be published on the MHRA Products website within seven days of approval. Taken together, the decision is a targeted regulatory approval rather than a broad change in cancer policy. It creates an additional licensed treatment option for adults with malignant ascites where standard cancer treatment is no longer feasible, while placing equal weight on specialist oversight, post-market surveillance and clear patient information.