'New Cancer Drug May Trigger Heart Problems'

The new drug is one of a family of new and powerful anti-cancer drugs called tyrosine-kinase inhibitors, which target key molecular pathways thought to encourage tumour growth. Other drugs in this family include imatinib, better known as Gleevec, and dasatinib (Sprycel), health portal HealthDay reported.

Scientists led by Ming Hui Chen, an assistant professor of medicine at Harvard Medical School and a cardiologist at Children's Hospital, Boston, studied 75 patients with stomach tumours that had not responded to the standard therapy with Gleevec.

The patients had taken part in a trial studying the efficacy of Sunitinib. The researchers looked back at the medical records of the studied patients, noting those who died from heart disease or had suffered heart attacks or congestive heart failure.

They also looked at the effect of Sunitinib on the heart's ability to pump blood and on blood pressure. Chen's team found that eight patients given repeated cycles of Sunitinib had cardiovascular events.

Two had heart attacks, and six had heart failure. Of the 36 patients given the approved dose of Sunitinib, 10 had a 10 percent or more reduction in the ability of their heart to pump blood, and seven had a 15 percent or more reduction in heart function.

In addition, Sunitinib was associated with increases in blood pressure, with a total of 35 (47 percent) of the patients developing hypertension, the scientists said in their findings published in the Dec 15 issue of The Lancet.

However, these effects were not permanent: When Sunitinib treatment was stopped and patients began therapy to ease heart problems, levels of heart failure and heart functioning improved, they said.

In addition, Chen's team found that Sunitinib triggered heart cells' damage and death when they experimented that drug on mice and rat heart cells.

The drug maker Pfizer Inc. agreed that these heart risks do exist. However, they added that the cardiovascular events were medically manageable in most patients.