Test for Drug Resistance in Leukemia Patients

A new test will monitor drug resistance in chronic myeloid leukemia (CML) patients who are treated with imatinib mesylate (Gleevac). Over 90% of patients treated with Gleevac initially respond to treatment and many experience complete remission. However, 4-5% of these patients eventually develop resistance to the treatment and experience a relapse in symptoms.

The specific target for Gleevac in CML patients is a mutation known as BCR-ABL. In relapsed patients the majority of secondary mutations in the ABL portion of the gene correlate with treatment failure. Genzyme Corporation (Cambridge, MA, USA) has developed a new test that detects all secondary BCR-ABL mutations and predicts resistance to Gleevac. The mutation analysis test will help physicians evaluate resistance to therapy and facilitate appropriate adjustments to treatment.

Gleevac was approved by the U.S. Food and Drug Administration (FDA) in 2001 as the first drug in a new class of molecular targeted therapies for CML. It is used as a first-line therapy because of its high efficiency and limited side-effects. The discovery of BCR-ABL mutations was made by researchers at the University of California Jonsson Cancer Center (UCLA, Los Angeles, CA, USA). They are currently working to determine whether the same mutations in CML patients might also lead to resistance to newer treatments under investigation.

Genzyme entered into a license agreement with UCLA to obtain exclusive worldwide diagnostic rights to UCLA's discovery of gene mutations believed to be associated with resistance to Gleevac.



Related Links:
Genzyme Corporation
University of California Jonsson Cancer Center