Gleevec Gets High Marks for Leukemia Treatment

March 22, 2011 -- When Jerry Mayfield was diagnosed with leukemia in 1999 his doctors gave him about three years to live. Twelve years later, Mayfield says he feels just fine.

What makes his survival story so remarkable is that it is not remarkable at all.

Mayfield has the blood cancer chronic myelogenous leukemia (CML), and he was among the first patients with the disease treated with the targeted biologic drug Gleevec.

Now new research confirms that the drug has transformed a previously fatal leukemia into a manageable chronic disease for many patients who take it.

Life Expectancy Improves

CML patients taking Gleevec (imatinib) were followed for up to eight years. In order to be enrolled in the study, patients needed to be incomplete remission after two years of starting the drug, and the study confirmed that they could expect to live as long as people without cancer.

Gleevec and two second-generation CML drugs that came after it are success stories in targeted cancer therapy.

Before Gleevec’s introduction a decade ago, fewer than half of patients with CML survived for more than seven years and the main drug treatment -- interferon -- left most people feeling miserable with fatigue and persistent flu-like symptoms.

Most patients who take Gleevec respond well to treatment and the new research confirmed that serious side effects are uncommon.

“This is the first study to show that a cancer that cannot be cured by surgery can be controlled to the point that patients have a normal life expectancy,” study researcher Carlo Gambacorti-Passerini, MD, of Italy’s University of Milano Bicocca tells WebMD. “This is quite remarkable.”

Checking for Adverse Events

The 832 patients in the study were followed for an average of about five years.

Twenty deaths occurred during follow-up, for a death rate of 4.8%. This was similar to the death rate that would be expected among people of the same age in the general population, Gambacorti-Passerini says.

Serious adverse events, including cardiovascular and digestive system problems, were reported in 139 patients, but only 27 cases were considered possibly related to Gleevec treatment.

Less serious, treatment-related adverse events were more common, occurring in more than half of patients. They included muscle cramps, weakness, diarrhea, skin fragility, and swelling.

The research was funded by Italy’s drug safety agency and it included patients treated in academic and research centers and community-based hospitals.

The study is published online in the Journal of the National Cancer Institute.

Why Does Gleevec Work So Well?

While other targeted drug treatments are being used for other cancers, they have not proven to be game changers like Gleevec and two other targeted CML drugs: Tasigna (nilotinib) and Sprycel (dasatinib).

Johns Hopkins University associate professor of oncology B. Douglas Smith, MD, says this is not surprising.