Onconase® is the trade name for ranpirnase, which is an experimental drug under study for the treatment of mesothelioma. Ranpirnase is a ribonuclease that is acquired from the egg of a leopard frog, also known as Rana pipens. Ranpirnase inhibits cell growth by interrupting the protein synthesis, which is necessary for growth. The drug has shown promising results in clinical trials. The standard survival rate for patients with malignant mesothelioma is 6 to 8 months. In a limited clinical trial of ranpirnase that included a population of 105 patients, the 1-year survival rate was greater than 34% and the 2-year survival rate was greater than 21%. The study, which included an evaluation of ranpirnase versus doxorubicin, indicates that the median survival times, 1-year survival rates and 2-year survival rates were similar for the two drugs. Doxorubicin is a standard drug that has been used historically in chemotherapy treatment for a number of other types of cancer. Further analysis of the data and patient’s prognostic factors indicates that ranpirnase may be more active in attacking cancer cells in certain subsets of patients. The success of the trial has led to the development of more advanced clinical trials. Advanced trials are evaluating the effects of combining ranpirnase with doxorubicin as a drug combination to be used for chemotherapy. Data from the use of the ranpirnase/doxorubicin combination will be compared with the effects of using ranpirnase alone  In 2006, the biopharmaceutical company, Alfacell Corporation, filed application with the US Food and Drug Administration (FDA) to obtain orphan designation for ONCONASE® for the treatment of patients with unresectable malignant mesothelioma. ONCONASE is currently being evaluated in clinical trials. In 2007, the FDA granted the company such a designation. The FDA orphan drug designation provides incentives for companies to develop drugs for the treatment of diseases affecting fewer than 200,000 people in the US. Unresectable malignant mesothelioma qualifies under this requirement. Orphan drug status entitles the company to seven years of marketing exclusivity for the drug. Other key benefits include protocol assistance from the FDA in the preparation of a dossier that will meet regulatory requirements, tax credits, grant funding for research and development, and reduced filing fees for the marketing application.