Data showing the ability of omacetaxine to kill leukemic stem cells in mouse models with drug-resistant chronic myelogenous leukemia (CML) are the subject of an advance online publication in the journal Leukemia, ChemGenex Pharmaceuticals Limited (ASX:CXS and NASDAQ:CXSP) announced today.
The findings of this study provide new insights into the problem of minimal residual disease and may open the door to the development of a curative treatment strategy for some patients with CML.
Commenting on the publication, Dr. Shaoguang Li, the study leader at the University of Massachusetts Medical School, said, "Omacetaxine killed 90% of the leukemic stem cells in vitro. In contrast, imatinib and dasatinib, the two leading CML drugs, only controlled 9% and 25% of these cancer stem cells, respectively. We further demonstrated that omacetaxine prolonged survival in test animals carrying the T315I mutation, which would normally render them resistant to all currently available drugs."
ChemGenex is currently developing omacetaxine as a potential treatment for a range of blood malignancies, including CML, and is completing a pivotal study in CML patients who harbor the T315I mutation. The company expects to complete its filing of a New Drug Application for use of omacetaxine in that patient population to the U.S. Food and Drug Administration by mid-year.
In the USA, almost 5,000 new cases of CML are diagnosed each year and recent estimates suggest that by 2025, prevalence will be 300,000. While there are a number of licensed drugs, collectively known as tyrosine kinase inhibitors (TKIs), which are very effective in treating CML, they must be administered daily for the rest of the patient's life; very few patients remain disease free when these drugs are discontinued.