The drug azacitidine (vidaza) dramatically improves the survival of patients who have high-risk forms of myelodysplastic syndromes (MDS), according to an published in the March issue of The Lancet Oncology.

MDS are a diverse group of bone-marrow disorders that frequently develop into acute myeloid leukaemia (AML). Besides bone-marrow transplantation, which is suitable for only a small proportion of patients, no other existing treatments provide a notable survival benefit for patients with higher-risk MDS.

In a large, multicentre, international phase III trial, Prof Pierre Fenaux of the Université Paris XIII, France, and colleagues assessed 358 patients with higher-risk MDS. 179 patients were randomly assigned to receive azacitidine injections for 7 days of each month, for at least 6 months; the remaining 179 patients were randomly allocated to one of the most commonly used conventional care regimens—best supportive care, low-doses of cytarabine, or classical intensive chemotherapy with an anthracycline and cytarabine—at their clinician’s discretion. Patients were followed up for a median of 21.1 months.

Overall survival was more than 9 months longer in patients treated with azacitidine than in patients who received conventional care (median 24.5 months vs 15 months); the survival benefit in the azacitidine group was seen after only 3 months of treatment. The researchers estimate that at 2 years after the start of treatment, twice as many patients on azacitidine as those receiving conventional care would still be alive.

Additionally, azacitidine treatment delayed progression to AML by 6 months (17.8 months to progression in the azacitidine group vs 11·5 months in the conventional care group); patients receiving azacitidine were also significantly more likely to undergo complete or partial remission than were those who received conventional care.

The frequency of severe blood-related side-effects was slightly higher in patients who received azacitidine than in patients who received best supportive care, but lower than in patients who received chemotherapy; additionally, the number of bleeding-related complications with azacitidine was similar to that with conventional care. There was a slightly lower rate of infections in the azacitidine group than in the conventional care group.

Prof Fenaux says that: “The results of this study indicate that azacitidine significantly lengthens overall survival and changes the natural history of MDS in patients with higher-risk disease”; azacitidine should, therefore, become the reference treatment in most patients with this condition. The authors also suggest, however, that: “intensive chemotherapy may remain the appropriate treatment in some situations in higher-risk MDS, especially before allogeneic stem-cell transplantation in candidates for this procedure who have an excess of marrow blasts.”

Watch interviews with Dr Lewis Silverman, principal Investigator of the randomised Phase III trial of Azacitidine vs. Supportive Care which served as the basis for approval of Azacitidine by the FDA for MDS in the United States