Formation of ascites, fluid in the peritoneal cavity, is a feature of many types of cancer when disseminated intrabdominally or in the liver.Ovarian cancer is a common and deadly disease, and most patients are not cured with available therapies, as the majority of cases are detected when already disseminated.While chemotherapy is often effective initially, resistant disease eventually emerges, often accompanied by ascites.The immunogenicity of oncolysis depends on the type of virus used, and adenovirus appears to be among the types of viruses most capable of inducing anti-tumor immunity.The oncolytic adenovirus H101 was given i.p. to patients with i.p. disease, as indicated by the presence of ascites and detection of tumor cells therein.The treatment was well tolerated, resulting in the usual adverse effects associated with i.p. administration of oncolytic adenoviruses: mild to moderate fever, fatigue, chills, and abdominal pain.Efficacy was evaluated by measuring the volume of ascites 4 wk later, and in many cases, it was decreased or even completely absent. Ascites control was achieved in 75% of cases.Use of oncolytic adenovirus for treatment of malignant ascites is a promising approach, and it was satisfying to read that they have initiated a prospective trial to investigate it further.