Ceflatonin, a drug to treat a form of leukemia, received the orphan drug status from the FDA. ChemGenex Pharmaceuticals Ltd, the maker of the blood cancer drug, said Ceflatonin (homoharringtonine) is currently being evaluated for chronic myeloid leukemia, myelodysplastic syndromes and acute myeloid leukemia.

The orphan drug status entitles ChemGenex to seven years of market exclusivity for the use of Ceflatonin in the treatment of chronic myeloid leukemia, protocol assistance by the FDA to optimize drug development in the preparation of a dossier that would meet regulatory requirements, and reduced fees associated with applying for market approval.

Two separate phase 2/3 clinical trials are planned to begin in the first half of 2006. The first study will be in patients with a specific bcr-abl point mutation (T315I) bcr-abl and the second in patients failing imatinib and dasatinib.

On the same lines, European Union had granted in September 2004, a designation for Ceflatonin in the European market, with similar advantages. The European Union had granted Ceflatonin orphan status on October 20, 2004 for the treatment of acute myeloid leukemia.

ChemGenex had received United States Patent and Trademark Office’ (USPTO) patent covering for Ceflatonin in January 2006 for "Treatment of chronic myelogenous leukemia, resistant or intolerant to ST1571, involving homoharringtonine alone or combined with other agents" and has been issued as U.S. patent number 6,987,103.

The patent covers the use of Ceflatonin in the treatment of chronic myeloid leukemia (CML) and Ph-positive acute lymphocytic leukemia (ALL) in patients who are intolerant or resistant to imatinib (Gleevec). In addition to covering the use of Ceflatonin as a single agent, the patent also covers use in combination with a range of drugs including cytarabine, interferon alpha, Gleevec, farnesyl transferase inhibitors (FTI's) and nucleoside analogs, in patients who are resistant to Gleevec.

Ceflatonin (sHHT) is a new, well-tolerated inducer of apoptosis in phase 2/3 clinical trials in chronic myeloid leukemia (CML) patients who have developed resistance to Gleevec.

ChemGenex Pharmaceuticals is a gene-based pharmaceutical development company developing novel protein, antibody and small molecule therapeutics in the areas of oncology, obesity, diabetes and central nervous system disorders. The company was formed in 2004 from the merger of AGT Biosciences of Melbourne, Australia and privately held ChemGenex Therapeutics, Inc. of Menlo Park, California.