Two Treatments Effective for Gleevec-Resistant Leukemia
Dasatinib and nilotinib effective in treating leukemias resistant to imatinib
WEDNESDAY, June 14 (HealthDay News) -- Two drugs, dasatinib and nilotinib, are safe and effective in treating leukemias with BCR-ABL tyrosine kinase mutations that are resistant to imatinib (Gleevec), according to two studies in the June 15 issue of the New England Journal of Medicine.
In the first study, Charles L. Sawyers, M.D., from the University of California Los Angeles, and colleagues administered escalating doses of dasatinib to 84 patients with chronic myelogenous leukemia or Philadelphia chromosome-positive acute lymphoblastic leukemia who were resistant or intolerant to imatinib. The researchers observed complete or partial hematologic responses in 68 patients, with cytogenetic responses in some patients.
In the second study, Hagop Kantarjian, M.D., from the University of Texas M.D. Anderson Cancer Center in Houston, and colleagues administered escalating doses of nilotinib to 119 patients with chronic myelogenous leukemia or acute lymphoblastic leukemia who were resistant to imatinib. The researchers observed hematologic responses in 57 of 91 patients and cytogenetic responses in 31 of 79 patients.
The studies are of "fundamental importance," writes Brian J. Druker, M.D., from the Oregon Health and Science University Cancer Institute in Portland, in an editorial. He notes that they provide hope for patients whose leukemia is resistant to imatinib, demonstrate the clinical value of understanding the molecular mechanisms of drug resistance, and show the rapid pace of drug development.
Several of the authors on the first study are or were employees of Bristol-Myers Squibb. The second study was supported by Novartis Pharmaceuticals.