Alfacell's Onconase Set To Start Phase III Testing

New Jersey, USA-based Alfacell is scheduled to begin Phase III testing of its ribonuclease drug Onconase (RNase or P-30 protein) in its first indication, pancreatic cancer, in September. Onconase is thought to be the first agent of this type to progress through to this stage of clinical testing.

The Phase III study will be conducted at 13 centers across the USA, with a target enrollment of 200 patients with stage III/IV pancreatic cancer. This form of cancer kills more than 25,000 Americans every year. The disease has a median survival rate of 90 days, and there are currently no standard effective treatments available. Onconase is one of the few drugs which had shown any activity as a single-agent therapy in this disease.

Mode Of Action Onconase is a structurally novel protein, which binds preferentially to membrane receptors on tumor cells and is internalized, probably by endocytosis. The ribonucleolytic activity of the molecule, derived from the leopard frog Rana pipiens, is not inhibited by mammalian RNase inhibitors. As a result, the mammalian ribosomal RNA is degraded, leading to the inhibition of protein synthesis and cell growth. These properties make Onconase selectively cytotoxic to tumor cells.