News & Events

- New Clinical Data Presented at EHA Suggests that Omacetaxine May Provide a Useful
Treatment Option for CML Patients Resistant to Multiple TKI Therapies -

ChemGenex Pharmaceuticals Limited (ASX:CXS) announced that positive, updated data from its phase 2/3 clinical trial study of omacetaxine in chronic myeloid leukemia (CML) patients with resistance to multiple tyrosine kinase inhibitors (TKIs) was presented at the 14th Congress of the European Hematology Association (EHA) in Berlin, Germany on Saturday.

Dr. Meir Wetzler MD, Chief of the Division of the Leukemia, School of Medicine and Biomedical Sciences, University at Buffalo, Roswell Park Cancer Institute, a lead investigator in the study, presented the data. Dr. Wetzler said, "TKIs are our front line of attack in CML, but significant numbers of patients have developed cross resistance to drugs in this chemical class. As a physician I need alternatives, so it is important to continue the search for new drug entities to treat refractory CML. The data emerging from this study provide encouraging signs that omacetaxine could offer a viable therapeutic option for this patient group."

Data were presented from 65 patients: 30 in chronic phase, 20 in accelerated phase and 15 in blast phase. Highlights of the data were:

Chronic phase patients
�?� Complete hematologic response (CHR) rate of 80% with a median response duration 7.5 months
�?� Major cytogenetic response (MCyR) rate of 20% with a median response duration 2.7 months

Accelerated phase patients
�?� CHR rate of 60% with a median duration 8.9 months

Blast phase patients
�?� CHR rate of 40% with a median duration 5.7 months

Tolerability
Investigators reported that omacetaxine is generally well tolerated, and that the most common side effect is reversible and transient myelosuppression.

Commenting on the presentation, Greg Collier, Chief Executive Officer and Managing Director of ChemGenex said, "Omacetaxine has a very different mechanism of action compared to the TKIs, and we have always believed that it may offer the potential to overcome TKI-resistance. The latest results of this study are very encouraging, but this clinical trial is still at an early stage. 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."

Dr. Collier and ChemGenex's Chief Medical Officer Dr. Adam Craig will host an investor conference call and webcast to discuss the clinical results from both ASCO and the EHA Congress on Thursday 11th of June at 10 am Australian Eastern Standard Time.

Webcast Details

Telephone access (toll free) details are below:

1800 131 617 Australia Free Call
+61 7 3107 0222 International / Metered Number
0800 446 958 New Zealand Free Call
800 120 4406 Singapore Free Call
800 962 283 Hong Kong Free Call
001 803 011 4106 Indonesia Free Call
0044 22 132 558 Japan Free Call
866 746 2596 USA/Canada Free Call
0800 376 8339 UK Free Call
0800 330 2094 Germany Free Call
0805 111 476 France Free Call
0800 001 230 Switzerland Free Call

Online: http://services.choruscall.com/links/chemgenex090611.html

About the trial

CGX-635-CML-203 is a phase 2/3 open-label study using omacetaxine as a subcutaneous injection for the treatment of patients with chronic myeloid leukemia (CML) who are intolerant to or have failed multiple TKIs.

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.