The Oncology Drug Advisory Committee (ODAC) to the US FDA did not recommend approval of Abbott’s oral investigational agent Xinlay (atrasentan) for the treatment of patients with hormone-refractory prostate cancer (HRPC) that has spread to the bone.

"Abbott respects the committee's vote on Xinlay; however, we continue to believe that Xinlay represents an important option for patients with advanced prostate cancer who currently have limited options," said Eugene Sun, vice president, Global Pharmaceutical Clinical Development, Abbott.

Xinlay is an investigational, oral, once-daily, non-hormonal, non-chemotherapy, agent that belongs to a class of compounds known as selective endothelin-A receptor antagonists (SERA). SERAs antagonize the effect of endothelin-l (ET-l), one of the proteins thought to be involved in the stimulation of the growth and spread of cancer cells. Abbott submitted a New Drug Application (NDA) in December 2004 seeking approval. The NDA for Xinlay supplied data on time to disease progression and delay in time to onset of bone pain.

"Eighty-five per cent of the men with hormone-refractory prostate cancer have disease that spreads to the bone," Joel Nelson, professor and chairman of urology, University of Pittsburgh School of Medicine said adding, "Debilitating bone pain is the cardinal symptom of this stage of the disease and there are currently limited choices to delay this in men."

Xinlay is being studied in earlier stage prostate cancer patients in an ongoing Phase III study in hormone-refractory prostate cancer patients without metastasis. This study is expected to be completed in 2006.