According to researchers, a pill that helps treat a difficult form of leukemia may cause serious heart damage. The drug, “Gleevec” (imatinib) works by targeting the deadly form of cancer’s underlying defect. While this drug has helped many people survive, researchers have pointed out this new risk.
The study, which was published in the journal Nature Medicine, points to evidence that shows the drug caused heart failure in 10 patients whom underwent the treatment. Gleevec has been hailed by many medical professionals for its ability to fight and stop the stubborn form of cancer known as chronic myelogenous leukemia (CML) in most patients.
The researchers looked at the 10 human patients. It turns out that all of them developed heart failure while on the drug. The researchers then tested Gleevec in both mice and lab dishes. What they found was that it appeared to be toxic to cardiac cells. In fact, the mice that were given Gleevec developed left ventricular dysfunction. This is a serious symptom of heart failure where the heart can’t pump blood out entirely.
According to other studies, thanks to the drug, anywhere between 80 and 90% of people on it who have CML remain cancer-free for at least five years. This is excellent news for people who are suffering with the disease, which was difficult to treat before the advent of Gleevec. Having come on the market in 2001, Gleevec also goes by the name “Glivec” in some countries and it’s produced by the pharmaceutical giant Novartis.
Regardless of this new finding, researchers were quick to note that cancer patients taking this drug should not stop treatment, but instead should be watched closely for possible indicators that heart damage is present. Other drugs that are in the same class as Gleevec — tyrosine kinase inhibitors — could also cause this unwanted side effect of heart damage or even potential heart failure, according to the researchers.
Thomas Force, who headed the study, commented that “We’re trying to call attention to the fact that Gleevec and other similar drugs coming along could have significant side effects on the heart and clinicians need to be aware of this. It’s a potential problem because the number of targeted agents is growing rapidly.”
Along with treating CML, Gleevec is also approved for treating another condition known as gastrointestinal stromal tumor (GIST), which is a rare type of stomach cancer. In CML, the way Gleevac operates is that it stops the activity of the protein known as “Bcr-Abl,” which causes a sufferer’s white blood cells to exhibit behavior that is out of control.
However, Force also said that “While the cancer is treated effectively, there will be some percentage of patients who could experience significant ventricular dysfunction and even heart failure from this.”
The researchers noted that Gleevec is indeed a very helpful drug, but that people who are taking it should be monitored by their health care providers for any signs of heart damage or related symptoms. Note that heart failure is a chronic condition that is very serious and can kill half of its sufferers within only five years’ time.
If you are taking Gleevec, you may want to discuss this finding with your doctor to see if you are at risk and what your options are.