Genzyme debut Gleevec resistance test

US biotechnology firm Genzyme has announced the availability of a new test to monitor drug resistance in chronic myeloid leukemia patients who are treated with Novartis' Gleevec (imatinib mesylate). Despite high response rates to Gleevec, approximately 4%-5% of patients who were initially treated successfully will develop resistance during therapy. Genzyme's new BCR-ABL Mutation Analysis test will assist physicians in evaluating resistance to therapy and facilitate appropriate adjustments to treatment.

The molecular hallmark of CML is a mutation known as BCR-ABL. This is the specific target for Gleevec and is found in 95% of patients with CML. In relapse patients, the majority of secondary mutations in the ABL portion of the gene correlate with treatment failure. The firm's new test detects all secondary BCR-ABL mutations and therefore predicts resistance to Gleevec.