Pfizer cancer drug may be linked to heart failure
Fifteen percent of patients with kidney cancer or gastrointestinal cancer, who were treated with Pfizer’s Sutent (sunitinib) experienced heart failure, according to a small study presented at the Genitourinary Cancers Symposium in San Francisco this week.

Sunitinib is an oral medicine approved by the FDA for the treatment of renal cell carcinoma (an aggressive form of kidney cancer) and a rare type of gastrointestinal cancer called gastrointestinal stromal tumor (GIST).

The drug works by inhibiting angiogenesis, the researchers said. Sunitinib is currently being widely tested for the treatment of other cancers, both early- and advanced-stage.

“Our data demonstrate the need for routine cardiac monitoring in patients receiving sunitinib,” said lead author Melinda Telli, MD, a postdoctoral fellow in medical oncology at Stanford University School of Medicine.

Telli and colleagues studied 48 patients who had either kidney or GIST between July 2004 and July 2007 at the Stanford University Comprehensive Cancer Center. Out of these patients, seven developed heart failure while on Sutent.

“Cardiac adverse effects need to be carefully examined in future 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,” Telli said.

The researchers noted that animal studies have shown that sunitinib can be toxic to cardiac cells and that this effect may be exacerbated by high blood pressure (another side effect of sunitinib). Previous studies have reported that up to 8% of patients taking sunitinib experienced heart failure, but patients in those studies were taking the drug as part of participation in a clinical trial.

The current study is the first to evaluate cardiovascular side effects in patients who were taking sunitinib outside of the context of a clinical trial, making them more representative of the general population of patients currently receiving sunitinib, according to the researchers.

In 2007, Pfizer reported that Sutent sales achieved more than $581 million.