Onconase (ranpirnase)

Currently in clinical trials, Onconase, manufactured by Alfacell Corporation, offers hope to patients with unresectable malignant mesothelioma.  Developed from the eggs of the leopard frog, Onconase is a ribonuclease protein that is designed to enhance the anti-cancer effects of traditional chemotherapy, allowing lower doses to be effective and causing fewer adverse side effects.  Though Onconase works slowly, its lower toxicity levels mean no loss of hair, anemia, or nausea usually associated with standard chemo drugs.

Technically speaking, Onconase slows down cancer cell growth by decaying RNA. Without certain RNA strands, cancer cells cannot produce certain essential proteins and, therefore, cannot replicate. This serves to slow the growth of the tumor. 

While Phase III trials are currently underway, treating approximately 300 patients that have been stricken with inoperable malignant mesothelioma, the results of Phase II trials, released in 2002, demonstrated that “the tumors either shrank or stopped growing in 41 of the 81 patients that were assessable for tumor response.”  The median survival of the patients who entered the trial without symptoms from the cancer was 18.5 months.

Onconase is also one of the first embryonic stem cell products to reach the final stages of testing.  Doctors hope to soon be using Onconase in place of Doxorubicin, a chemotherapy drug with crippling side effects that have a serious effect on the patient’s quality of life.