Omacetaxine

Omacetaxine mepesuccinate is an apoptotic agent that induces apoptosis by inhibition of protein synthesis, particularly Mcl-1. It acts independently of tyrosine kinase inhibitors, it has therapeutic advantages for patients who have developed resistance to tyrosine kinase inhibitor therapy.

In vitro and animal model trails are promising and recent results showed that omacetaxine has potential to treat resistant leukemia mainly CML and ALL.

Clinical trials in CML patients who have failed imatinib therapy and who have the T315I point mutation might have started already or on the way.

Recently Chemgenex released results of their open label Phase 2/3 study (CGX-635-CML-202) which investigated the use of omacetaxine, administered subcutaneously in CML patients who had failed imatinib and who have the highly drug resistant T315I kinase domain mutation.

Dr. Jorge Cortes, MD, Professor of Medicine and Deputy Chair in the Department of Leukemia at The University of Texas, MD Anderson Cancer Center, a lead investigator in the study, presented the data. Dr. Cortes said, “It appears that omacetaxine was well tolerated in this study and durable hematological and cytogenetic responses were observed in some CML patients with the T315I mutation.” He added that “Several novel drugs have already been investigated in this difficult-to-treat population, but they have not had a reasonable risk:benefit ratio. These results suggest that omacetaxine may represent the first viable treatment option for this population of patients who currently have no established treatment options.”

Further studies might show benefits in treating MDS, acute myelogenous leukemia (AML) and solid tumors.