Sunitinib (Sutent) causes heart failure more often than previously recognized, according to a small study of people with renal cell carcinoma (a type of kidney cancer) and gastrointestinal stromal tumor (GIST). Sunitinib is a drug in the form of a pill taken by mouth that blocks the formation of new blood vessels that are needed for a tumor to grow and spread.

This study examined data on the appearance of heart failure symptoms from 48 patients who had been treated for renal cell carcinoma or GIST with sunitinib between July 2004 and July 2007 at the Stanford University Comprehensive Cancer Center. Of these patients, seven (15%) had symptoms of heart failure during treatment. These symptoms began as early as 22 days and as late as 435 days after beginning treatment and continued after the use of sunitinib was stopped and treatment for heart failure began. Patients with a history of heart failure or coronary artery disease or a low body mass index (BMI, the ratio of a person's weight and height) were more likely to have symptoms of heart failure during sunitinib treatment.

“The results of this study demonstrate the need for regular heart monitoring in patients receiving sunitinib,” said lead author Melinda Telli, MD, a Postdoctoral Fellow in Medical Oncology at Stanford University School of Medicine in California. “Heart-related side effects need to be carefully examined in future clinical trials of sunitinib to determine the factors that place patients at risk for this complication. That information will allow us to administer this medication more safely to patients for whom the benefits of treatment clearly outweigh the risks.”

Previous clinical trials have shown that up to 8% of people taking sunitinib have symptoms of heart failure. However, people with pre-existing heart conditions are often excluded from participating in such clinical trials. This study is the first to examine the heart-related side effects of sunitinib outside of a clinical trial setting.

What this means for patients

Before beginning treatment with sunitinib, people should talk with their doctor about the risks and benefits of sunitinib and discuss any history of high blood pressure or other heart problems. Patients taking sunitinib need to be aware of the signs of heart failure, which can include shortness of breath and fatigue.