Ariad Pharmaceuticals, Inc. announced that AP23464, its lead product candidate to treat certain forms of leukemia, is highly effective in blocking the growth of leukaemia cells harboring clinically relevant mutations commonly observed in patients who have become resistant to Gleevec (imatinib) - today's mainstay of leukaemia treatment. The research was conducted by a team headed by Brian Druker, MD, Jeld-Wen chair of Leukaemia Research and professor of Medicine, Oregon Health & Science University Cancer Center, who played a key role in the discovery and development of Gleevec.

Gleevec is a trademark of Novartis AG.

Although Gleevec is an effective treatment of chronic myelogenous leukaemia (CML), relapse is occurring in a growing number of patients, especially those with advanced-stage disease. Most patients who develop resistance to Gleevec have leukemias with readily identifiable mutant Abl proteins not inhibited by Gleevec, leading to reactivation of excessive Abl activity.

AP23464 is a promising product candidate for the treatment of such patients because of its potency against a broader array of therapeutic targets, including the native and mutated forms of Abl. The latest study also confirmed that AP23464 is substantially more potent than Gleevec in blocking Abl.

"Dr Druker's groundbreaking work in treating patients with leukaemia has been widely recognized by the hematology community. His group's research provides persuasive evidence that AP23464 may be a compelling alternative or complement to Gleevec - both for Gleevec-resistant patients and as primary therapy for certain forms of leukemia. These data should facilitate filing of an IND for AP23464 by the end of next year," said Harvey J Berger, MD, chairman and CEO of Ariad.

Ariad's small molecule, AP23464, is designed not only to treat certain forms of leukaemia but also to treat and prevent the spread of cancer by inhibiting the activity of another cancer-related protein Src, which regulates the process by which cancer cells spread from primary to distant sites in the body.