Two New "Targeted" Leukemia Drugs Show Promise

Two experimental drugs could offer hope to leukemia patients who no longer benefit from Gleevec, the groundbreaking cancer pill, research presented Sunday in San Diego at the meeting of the American Society of Hematology shows. Gleevec, approved in 2001 to treat chronic myeloid leukemia, is one of the first of a new class of "targeted" therapies that attack cancerous tumors but not the surrounding tissue. This way, patients are spared the side effects of traditional chemotherapy. Gleevec, made by Novartis, targets a specific mutation in an enzyme called BCR-ABL that allows cells to multiply unchecked. The Gleevec molecule shuts down this runaway growth by binding to the mutated enzyme, fitting like a lock in a three-dimensional key.