ChemGenex Pharmaceuticals Limited has agreed with the US Food and Drug Administration (FDA) a potential regulatory path to progress Omapro (omacetaxine mepesuccinate) for the treatment of patients with Chronic Myeloid Leukaemia (CML).

The recent Type A Meeting, which included discussion of a regulatory path forward, addressed outstanding issues regarding the previously received Complete Response letter dated 8 April 2010.

Based on the discussion with the US FDA, ChemGenex intends to combine data from its two pivotal studies, Study 202 and Study 203, and submit a New Drug Application (NDA) for OMAPRO for those patients with CML who have failed prior treatment with two or more currently approved tyrosine kinase inhibitors (TKIs). The proposed indication of this new NDA will be for the treatment of CML patients who have failed two or more TKIs, regardless of their mutation status.

"The FDA's agreement that a combined data set could serve as the basis of an NDA in a third-line setting provides us with a pathway to an expanded indication for OMAPRO to treat CML patients who are resistant to at least two TKIs," said Adam Craig, chief medical officer of ChemGenex.

"We also appreciate FDA's invitation to discuss this approach further in a pre-NDA meeting," he added. "We welcome the opportunity granted by the agency to submit combined data from our two completed pivotal studies and to potentially provide a new therapeutic choice for this significant group of patients who currently have very limited treatment options."

Greg Collier, managing director and chief executive officer of ChemGenex added, "We are pleased with the outcome of this Type A meeting as it provides another option for advancing the development timeline for OMAPRO. By pursuing this new indication for multi TKI-resistant patients, OMAPRO can potentially treat a significantly larger patient population in the United States, and we plan to submit our new NDA to the FDA by the end of the year."

ChemGenex is continuing its discussions with the FDA's Center for Devices and Radiological Health towards approval of a diagnostic test for the T315I mutation, and the existing NDA for T315I positive CML patients who have failed imatinib remains open.

The company also has a Marketing Authorisation Application under review with the European Medicines Agency for CML patients who have failed imatinib and have the T315I mutation. This review is on track, with a potential approval in Europe in the first quarter of 2011.

Omacetaxine is a first-in-class cetaxine with demonstrated clinical activity as a single agent in a range of hematological malignancies.

ChemGenex is an oncology focused biopharmaceutical company developing small molecules with new mechanisms of action to treat malignancies with significant unmet medical needs.