Genzyme Corporation has announced the availability of an important new test to monitor drug resistance in chronic myeloid leukemia (CML) patients who are treated with Gleevec (imatinib mesylate).
Despite high response rates to Gleevec, approximately four to five percent 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 mutation is the specific target for Gleevec and is found in 95 percent of patients with CML. In relapse patients, the majority of secondary mutations in the ABL portion of the gene correlate with treatment failure. Genzyme's new test detects all secondary BCR-ABL mutations and therefore predicts resistance to Gleevec.
"This is a very exciting time for leukemia patients and their caregivers because this test will provide them with more information about their disease and will give them the ability to personalize their treatment," said Mara Aspinall, president of Genzyme Genetics, the business unit of Genzyme Corp. focused on the research and development of high quality, complex testing services.
"We are pleased to offer another important predictive test that can play a critical role in the way oncologists and patients manage their cancer," she added. Genzyme recently launched several other personalized medicine tests in the areas of lung cancer and leukemia and lymphoma.
Because of its high efficacy and limited side effects, Gleevec as a first- line therapy is considered to have revolutionized long-term survival of patients with CML. Gleevec was approved by the U.S. Food and Drug Administration in May, 2001 as the first drug in a new class of molecular targeted therapies for CML. Over 90 percent of patients treated with Gleevec respond initially to treatment, and many experience a complete remission. However, four to five percent of these patients eventually develop resistance to the treatment and experience a relapse of their disease.
The discovery of the BCR-ABL mutations was made by researchers at the University of California at Los Angeles (UCLA) Jonsson Cancer Center in 2001, who are currently working to determine if the same mutations in patients with CML may also lead to resistance to newer investigational treatments.
In October, Genzyme announced that it 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 drug resistance to Gleevec.