These drugs recently received final approval from the U.S. Food and Drug Administration (FDA):
• Regular approval for another indication of imatinib mesylate (Gleevec) by Novartis Pharmaceuticals Corp. The FDA has granted imatinib mesylate (Gleevec) regular approval as a second-line treatment for refractory chronic myeloid leukemia (CML).
Regular approval means that the FDA has determined that imatinib mesylate has demonstrated a long-term clinical benefit for refractory CML patients. When imatinib mesylate was originally approved under the accelerated approval program in May of 2001, available evidence indicated that a long-term clinical benefit was highly likely but further studies were necessary to confirm it. Imatinib mesylate’s promising effects included a normalization of blood cell counts and a reduction in the percent of abnormal chromosomes in bone marrow white blood cells.
As part of the original approval, Novartis Pharmaceuticals was required to continue to follow patients in their initial studies to confirm long-term benefit for this particular indication. Data presented to the FDA showed that 95% of patients achieved normal blood cell counts. Further, favorable treatment responses were sustained. An estimated 88% of patients who achieved a reduction in the percent of abnormal chromosomes in bone marrow white blood cells maintained that response for at least two years. After two years of treatment, an estimated 85% of patients were free of disease worsening. The estimated overall survival was 91%. As a result of these additional data, the FDA granted regular approval to imatinib mesylate in this particular treatment setting.
Since May 2001, imatinib mesylate has been approved for use in the first-line treatment CML, for use in pediatric leukemia, and for a gastrointestinal stromal cancer.