Name of the Trial
Phase II Randomized Study of Imatinib Mesylate at Standard Versus Increased Dose or Dasatinib in Patients with Previously Untreated Chronic Phase Chronic Myelogenous Leukemia (SWOG-S0325). See the protocol summary at http://cancer.gov/clinicaltrials/SWOG-S0325.

Principal Investigators
Drs. Brian Druker and Marilyn Slovak, SWOG; Dr. Peter Emanuel, ECOG; Dr. Martha Wadleigh, CALGB; Dr. Jeffrey Lipton, NCIC  

Why This Trial Is Important
Development and approval of the drug imatinib ¹ (Gleevec) revolutionized the treatment of chronic myelogenous leukemia (CML). CML is usually characterized by a genetic mutation, called the Philadelphia chromosome, that results in the creation of an abnormal protein called Bcr-Abl. Imatinib inhibits the activity of Bcr-Abl, thereby blocking the uncontrolled growth of CML cells and causing them to die.

However, imatinib does not work for some patients, and it sometimes stops working if CML cells develop resistance to it. Therefore, researchers are interested in determining whether the standard dose of imatinib used as initial therapy for CML should be changed, or if a different targeted drug might be more effective.

In this trial, doctors will compare the effectiveness of imatinib at the standard dose versus an increased dose and against a new drug called dasatinib ² (Sprycel). Dasatinib binds to the Bcr-Abl protein more readily than imatinib and has demonstrated the ability to kill CML cells that have become resistant to imatinib.

“The current standard treatment for CML is 400 mg of imatinib a day,” said Dr. Druker, “and that produces a response in about 90 percent of patients. Treatment for this disease is evolving rapidly, however, and newer, more potent drugs are now available. With this trial, we hope to define the best treatment options for patients newly diagnosed with CML.”

Who Can Join This Trial
Researchers will enroll approximately 335 patients with previously untreated, chronic-phase CML. See the list of eligibility criteria at  http://www.cancer.gov/clinicaltrials/SWOG-S0325.

Study Sites and Contact Information
Study sites in the United States are recruiting patients for this trial. See the list of study contacts at http://www.cancer.gov/clinicaltrials/SWOG-S0325 or call NCI’s Cancer Information Service at 1-800-4-CANCER (1-800-422-6237) for more information. The toll-free call is confidential.