Ranpirnase is a ribonuclease enzyme found in Northern Leopard Frog (Rana pipiens) oocytes. It is being studied in the treatment of cancer, specifically in pleural and peritoneal mesothelioma. It is manufactured by Tamir Biotechnology, Inc. (formerly Alfacell Corporation) of Monmouth Junction, NJ and known by the ONCONASE trademark. ONCONASE failed in Phase III clinical trials due to safety issues. Onconase has been demonstrated as selectively cytotoxic against tumor cells[1] and has been used empirically to treat malignant mesothelioma patients, with some patients experiencing prolonged survivals.[2]
A related therapeutic, QBI-139, is in Phase I trial.[3] QBI-139 is an analog of human ribonuclease.
According to the company, this is a biopharmaceutical product candidate that works in a manner similar to RNA interference (RNAi). The product candidate, ONCONASE, is an RNase that "overcomes the challenges of targeting RNA for therapeutic purposes while enabling the development of a new class of therapies for cancer, viral, and other life-threatening diseases." Currently, Tamir is conducting a Phase II clinical trial with the addition of RANPIRNASE (ONCONASE) to PEMETREXED plus CARBOPLATIN in patients with non-squamous, non-small cell lung cancer (NSCLC).
Also according to the company, "ONCONASE is a first-in-class therapeutic based on Tamir's proprietary ribonuclease (RNase) technology. A natural protein isolated from the leopard frog, ONCONASE has been shown in the laboratory and clinic to target cancer cells while sparing normal cells. ONCONASE triggers apoptosis, the natural death of cells, via multiple molecular mechanisms of action."