Aranesp Increases Risk of Stroke for Some Patients: Study

New research suggests that side effects of Aranesp, an anemia drug, could increase the risk of stroke in some patients.

According to a study published Friday in the online edition of the New England Journal of Medicine, diabetes patients on Aranesp faced nearly twice the risk of stroke when compared to those taking a placebo. The results were also presented at the annual meeting of the American Society of Nephrology in San Diego, and the researchers suggested that in many people the risk of Aranesp side effects may outweigh the benefits.

Researchers looked at more than 4,000 patients with diabetes, chronic kidney problems and anemia, to evaluate whether the drug may reduce the risk of death, heart attacks, congestive heart failure, stroke or end-stage renal disease. About half of the participants in the study were given Aranesp (darbepoetin alfa) and the other half received a placebo.

The study concluded that the use of Aranesp among these diabetes patients with moderate anemia, who were not undergoing dialysis, did not reduce the risk of either death or a cardiovascular event, and actually increased the risk of stroke.

The results reinforce the findings of a previous 2008 study that indicated Amgen’s Aranesp (darbepoetin alfa) and Epogen (Epoetin alfa) may increase the risk of death in cancer and stroke patients. Epoetin Alfa is also sold by Johnson & Johnson as Procrit.

In 2007, the FDA issued a public health advisory regarding the anemia drugs, saying that they could increase the risk of injury or death at high doses. The FDA required that the drugs carry a “black box warning” alerting patients to the risk of blood clots, strokes, heart attacks and death. The black box warning is the strongest label warning the FDA can require of a medication.

Aranesp, Epogen and Procrit belong to a family of drugs known as erythropoiesis-stimulating agents, which are prescribed for patients with kidney disease and anemia. They are also used by HIV patients whose anemia is caused by AZT (zidovudine) and for patients about to undergo major non-heart surgery. The medications reduce the number of transfusions the patient must undergo.

In the new study, researchers found that 101 patients using Aranesp had fatal or non-fatal strokes, compared with only 53 patients taking the placebo. The scientists estimated that the risk of stroke on Aranesp was about 2%, as compared to 1% in the control group.

There was also a slight increase in the risk of cardiovascular events for patients taking Aranesp, as compared to patients taking a placebo. Researchers said 632 patients on Aranesp had a cardiovascular event, compared to 602 patients on the placebo.

The study’s authors determined that people with severe kidney disease may benefit from the lower number of transfusions required when taking Aranesp, but in many cases the health risks probably outweigh the benefits.

Amgen officials have said that the study’s results surprised them, and that they are considering labeling changes for the drug.