Ranpirnase--an antitumour ribonuclease: its potential role in malignant mesothelioma.

Ranpirnase (Onconase) is a novel cytotoxic ribonuclease. In clinical development as a single agent in patients with malignant mesothelioma (MM), at 480 microg/m2 intravenously weekly, analysis of survival indicated prolonged periods of stable disease in Phase II trials and a potential survival benefit, compared with doxorubicin, in a small unpublished Phase III trial. In all clinical studies it has generally demonstrated a favourable safety profile except for easily controlled allergic reactions and dose modifications for renal impairment. Standard first-line treatment for MM has recently been established with an antifolate and cisplatin. At present, a Phase III trial of doxorubicin with or without ranpirnase is nearing completion in MM patients without prior chemotherapy or one prior chemotherapy regimen.