CHICAGO - Pfizer Inc.'s cancer drug Sutent may have toxic effects on the heart, US researchers said yesterday.
Nearly half of 75 patients with rare gastrointestinal tumors who took the drug in a clinical trial developed high blood pressure, 8 percent developed heart failure, and two patients had heart attacks, according to a new analysis of the data by researchers at Children's Hospital Boston, the Dana-Farber Cancer Institute in Boston, and Thomas Jefferson University in Philadelphia. The data suggest patients taking the drug - and especially those with heart risks - should be closely monitored.
"If a patient develops shortness of breath, fatigue, and swelling of the feet and hands, they should seek medical attention," said Dr. Ming Hui Chen, a cardiologist at Children's. Most patients in the study responded to medications to control their symptoms, she said.
The finding follows the discovery last year that the Novartis AG drug Gleevec, for leukemia, caused heart failure in 10 patients.
The findings raise concerns that so-called smart drugs, which target specific signaling molecules inside cancer cells, may be interfering with signaling systems needed for the survival of normal cells, including heart cells.
Pfizer said larger studies of the drug showed lower incidences of heart effects.
