Pharmion Corporation announced that the US Food and Drug Administration (FDA) has accepted for filing and granted priority review classification for the company's New Drug Application (NDA) for Vidaza (azacitidine for injectable suspension) for the treatment of myelodysplastic syndromes (MDS). Priority review status of the application reduces the standard agency response time to six months, and targets an agency response on or before June 29, 2004.

"The FDA's acceptance of our Vidaza application for filing and designation of priority review status represents a significant milestone for Pharmion," said Patrick Mahaffy, CEO of Pharmion. "There are currently no approved therapies for MDS, and we look forward to working closely with the FDA in the coming months as we seek regulatory approval for this potential new treatment for this very serious disease."

Vidaza has been granted orphan product designation by the FDA, which, if the NDA is approved, entitles the drug to seven years of market exclusivity for MDS in the US Pharmion submitted the NDA under the provisions of the Subpart H Accelerated Approval of New Drugs for Serious or Life-Threatening Illnesses on December 29, 2003. As a condition of its NDA submission, Pharmion is required to conduct a confirmatory study of Vidaza in the treatment of MDS.

In September 2003, Pharmion initiated a confirmatory clinical trial comparing the effect of Vidaza to conventional care options on survival in patients with MDS. The study, which will examine survival outcomes as well as secondary endpoints, will recruit more than 350 patients at treatment centers across the US, Europe and Australia and will be one of the largest studies to date in this disease.

The NDA submission was based upon an NCI-sponsored Phase III study for the treatment of MDS, conducted by Cancer and Leukemia Group B (CALGB), and two supportive Phase II CALGB studies, which were also sponsored by the NCI. The results of this Phase III study were published in the May 2002 Journal of Clinical Oncology.

MDS is a bone marrow disorder characterized by the production of abnormally functioning, immature blood cells. The highest prevalence of MDS is in patients over 60 years of age. According to the American Cancer Society, there are an estimated 10,000-20,000 new cases of MDS in the United States each year. Survival rates range from six months to six years for the different subtypes of MDS. MDS can result in death from bleeding and infection in the majority of patients, and transformation to acute myelogenous leukemia (AML) occurs in up to 40 per cent of patients. The prognosis for patients transforming to AML is exceptionally poor.