FDA approves Pharmion's Vidaza

Pharmion Corporation, Boulder, Co, US, has received full approval from the FDA to market Vidaza for the treatment of Myelodysplastic Syndromes (MDS).

The FDA approved Vidaza for treatment of all five MDS subtypes. These subtypes include:

refractory anaemia (RA)

refractory anaemia with ringed sideroblasts (RARS) (if accompanied by neutropenia or thrombocytopenia or requiring transfusions),

refractory anaemia with excess blasts (RAEB),

refractory anaemia with excess blasts in transformation (RAEB-T), and

chronic myelomonocytic leukaemia (CMMoL).

Pharmion intends to make Vidaza commercially available within several weeks.

'The approval of Vidaza represents a significant milestone for Pharmion and, more importantly, represents an important new option for patients being treated for Myelodysplastic Syndromes,' said Patrick Mahaffy, president and chief executive officer of Pharmion. 'Until today, there have been no approved therapies for the treatment of MDS. We are proud to have advanced the work of the National Cancer Institute, the Cancer and Leukaemia Group B (CALGB) and other academic institutions and clinicians to the point that this drug can now be commercially available to treat this very serious and life threatening disease.'

MDS is a bone marrow disorder characterised 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 and the Aplastic Anemia and MDS International Foundation, there are an estimated 10,000-30,000 new cases of MDS in the United States each year. Survival rates range from six months to many 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 leukaemia (AML) occurs in up to 40% of patients. The prognosis for patients transforming to AML is exceptionally poor.

Mechanism of Action: Demethylation

Vidaza is believed to exert its anticancer effects by causing demethylation, or hypomethylation, of DNA in abnormal blood-forming (hematopoietic) cells in the bone marrow as well as through its direct cytotoxic effect. Demethylation may restore normal function to tumour-suppressor genes, which are responsible for regulating cell differentiation and growth. The cytotoxic effects of azacitidine cause the death of rapidly dividing cells, including cancer cells that are no longer responsive to normal growth control mechanisms. Non-proliferating cells are relatively insensitive to Vidaza. "In addition to being the first drug approved for the treatment of MDS, Vidaza is the first of a new class of compounds called demethylation agents to be approved," said Judith Hemberger, Pharmion's co-founder and chief operating officer. "We look forward to further exploring the clinical role of Vidaza in the treatment of other cancers in which demethylation may provide a benefit."