( luated their data. Theyfound that 77 p...)Dasatinib Shows High Early Response Rate as First Treatment for,Chronic Myelogenous Leukemia, M. D. Anderson Researchers Report,Health

This rapid response compares favorably to historical data on patients at M. D. Anderson who took imatinib as a first therapy, Atallah noted. Imatinib's complete response rates at six months are 54 percent at 400 mg daily and 85 percent for 800 mg daily. However, at 12 months, 72 percent of patients receiving imatinib 400 mg and 92 percent of those receiving 800 mg had a complete cytogenetic response.

Dasatinib side effects have been manageable and mainly low-grade, with 15 patients having to temporarily stop treatment.

The M. D. Anderson clinical trial is set to enroll 100 patients. The comparison to historical data provides insight into dasatinib's effect, but a randomized clinical trial comparing medications directly would present a more detailed picture.

Imatinib, known commercially as Gleevec and produced by Novartis Pharmaceuticals, was the first drug to target the fusion protein BCR-ABL that causes the disease. Before Gleevec, the median five-year survival rate for CML patients was 50 percent. Researchers reported last year that the five-year survival rate of patients taking imatinib is 95 percent.

About 4,500 people receive a diagnosis of CML in the United States each year, and an estimated 20,500 people are living with the disease, according to the Leukemia & Lymphoma Society.

Co-investigators with Atallah are senior researcher Jorge Cortes, M.D., Hagop Kantarjian, M.D., Susan O'Brien, M.D., and Gautam Borthakur, M.B.B.S., all of the M. D. Anderson Department of Leukemia; Daniel Jones, M.D., Ph.D., of the M. D. Anderson Department of Hematopathology; and Claude Nicaise, M.D., of Bristol-Myers Squib Co.

Bristol-Myers sponsors the clinical trial.

Cortes reports having received research grants from Bristol-Myers Squibb. Kantarjian reports ha
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