The British Medicines and Healthcare products Regulatory Agency (MHRA) has approved the use of catumaxomab for treating malignant ascites—a pathological accumulation of fluid in the abdominal cavity that occurs as a result of cancer. This condition is often accompanied by severe symptoms and significantly reduces the quality of life for patients requiring palliative care. According to the regulator, catumaxomab, like any other licensed medicine, will remain under continuous monitoring by the MHRA. This involves regular surveillance of data on the drug's safety and efficacy after its market release, which is standard practice for all new and already registered medicines. The drug's approval opens additional opportunities for physicians in treating cancer patients complicated by malignant ascites. The MHRA's decision is based on an evaluation of available clinical data for the drug, which confirms its therapeutic benefit for this indication. The regulator emphasized that post-market surveillance of medicines is an integral part of the healthcare system, allowing for the timely identification of potential risks and ensuring patient safety in the long term.