Human leukemic stem cells are known to be insensitive to tyrosine kinase inhibitors (TKIs), the drug family currently approved to treat Chronic Myeloid Leukemia (CML)

Ms Elaine Allan, clinical scientist of the Scottish National Blood Transfusion Service working at Paul O'Gorman Leukaemia Research Centre, University of Glasgow delivered the presentation.

Allan said, “Currently licensed drugs target and disable the diseased cells in the blood stream and bone marrow, but they have little, if any, effect on the primitive leukemic stem cells that are at the “root” of this blood cancer. In contrast, we have shown omacetaxine to be not only anti-proliferative, but also to induce apoptosis (programmed cell death) in human CML stem cells.”

Hagop M. Kantarjian, MD chairman and Professor, Department of Leukemia, at the University of Texas M D Anderson Cancer Center, described the study results as exciting. He added, “These results raise a possibility of eradicating the dormant malignant stem cells  thought to be responsible for relapse in CML patients who discontinue TKIs. I look forward to work with ChemGenex in future trials to evaluate the clinical application of this research."

Dr Greg Collier, CEO and MD of ChemGenex, said, “The data presented today is entirely consistent with our strategic plans to investigate omacetaxine in combination with selected TKIs in an attempt to eradicate this form of leukemia. In the meantime ChemGenex remains focused on our primary objective of developing omacetaxine as a therapeutic option for CML patients who have developed the T315I mutation. This is one of the most pressing unmet medical needs in the field of CML management.”

Omacetaxine overview
Omacetaxine mepesuccinate is a first-in-class cetaxine with demonstrated clinical activity as a single agent in a range of hematological malignancies. Omacetaxine has a novel mechanism of action, specifically binding to the ribosomal A-site cleft and inhibiting protein translation of short-lived oncoproteins that are upregulated in leukemic cells (particularly Cyclin-D1, Mcl-1 and c-Myc).

As omacetaxine acts independently of tyrosine kinase inhibitors, it may have a therapeutic advantage for patients who have developed resistance to TKIs. Omacetaxine is administered subcutaneously.

Clinical trials details