Omacetaxine mepesuccinate (formerly known as Ceflatonin®, homoharringtonine or HHT) is a first-in-class small molecule with established clinical activity as a single agent in a range of hematological malignancies. Omacetaxine has a novel mechanism of action, and induces apoptosis by inhibition of protein synthesis, particularly Mcl-1. As omacetaxine acts independently of tyrosine kinase inhibitors, it has therapeutic advantages for patients who have developed resistance to tyrosine kinase inhibitor therapy. Omacetaxine is administered subcutaneously.

We are currently conducting registration-directed clinical trials in CML patients who have failed imatinib therapy and who have the T315I point mutation. These patients, who are increasing in number, do not respond to TKI therapy. Preliminary data presented at ASH in 2007 reported complete cytogenetic responses in 20% of chronic phase patients, and hematologic and/or cytogenetic responses in 91% of chronic phase patients. ChemGenex received Fast Track Status for omacetaxine this sub-set of CML patients form the U.S. FDA in November 2006.

In addition to this registration-directed clinical trial, we have a phase 2 trial in CML patients who have failed multiple TKI therapies, and a phase 2 trial in AML patients.

ChemGenex’s development strategy is to seek initial approval for omacetaxine in T315I+ CML as a single agent. We also plan to develop omacetaxine as a single agent in multi-TKI resistant CML patients and as a combination therapy with TKIs in some CML patients. Opportunities for development and possible approval in MDS, acute myelogenous leukemia (AML) and solid tumors will also be pursued.

ChemGenex has one issued patent and has filed nine patent applications covering omacetaxine compositions, formulations, synthesis and uses.