Drug for Chronic Myeloid Leukemia Shows 89 Percent Survival After Five Years

Results of a clinical trial show that 89% of patients taking imatinib (Gleevec) to treat chronic myeloid leukemia (CML) are alive five years later. This is the longest and largest study of imatinib for newly-diagnosed patients with CML.

In this study, 1,106 patients with untreated, chronic phase CML (the most common phase at diagnosis) received either imatinib or interferon with cytarabine (Cytosar-U), which was the standard treatment when the trial began. None of the patients received previous treatment with chemotherapy.

At five years, the survival of the patients who received imatinib was 89%.The cancer did not move into the more serious accelerated or blast crisis phases in 93% of the patients. During the most recent year of treatment, fewer patients' cancers advanced to the accelerated or blast crisis phases, compared with each of the previous years, providing hope that the longer patients are on the drug, the less likely their disease is to advance.

Only 5% of patients discontinued imatinib because of side effects. Severe side effects included rashes, elevated liver enzyme levels, and fluid retention. More common and less severe side effects included puffiness around the eyes, mild nausea, diarrhea, and muscle cramps.

"Our hope is that patients can stay on this drug for an indefinite period," said Brian Druker, MD, Professor of Medicine at Oregon Health and Science University in Portland and lead author of the study. "Although this drug does not completely remove the disease in patients, we're gaining confidence that patients will continue to do well, and that their futures are really quite hopeful."

What This Means For Patients

Previously, CML tended to relapse (return) in many patients after two or three years.

This study provides evidence that imatinib, a pill taken by mouth, continues to effectively treat CML five years after diagnosis with few side effects.