Considerable stroke risk linked to anemia drug; Darbepoetin-α [Aranesp] nearly doubled risk in people with diabetes

November 1, 2009 – A new study raises fresh safety concerns about widely used anemia medicines, finding that the drug Darbepoetin-α [Aranesp] nearly doubled the risk of stroke in people with diabetes and chronic kidney problems who are not yet sick enough to need dialysis. The study is the largest ever of these blood-boosting drugs and the only one that compared them to a dummy treatment. The medicines have become blockbuster sellers because they lessen the need for transfusions, but their ability to prevent heart attacks, kidney failure or other problems have not been proven.

Over the last two years, the federal Food and Drug Administration has repeatedly strengthened warning labels not only on Darbepoetin-α [Aranesp] , but on the similar drug products Epoetin-α [Epogen] and Epoetin-α [Procrit] as concerns rose that they may worsen survival in certain cancer patients, especially at higher doses.

The new study tested Darbepoetin-α [Aranesp] in a different group of patients: 4,038 people with Type 2 diabetes, kidney problems and moderate anemia  problems that often go hand in hand. The goal was to see if the drug could prevent heart attacks, heart failure, strokes or the need for dialysis. The leader of the study, Dr. M. Pfeffer, noted that the study did not only fail to do that, but a susbstantial  hightened risk for stroke was uncovered.  Strokes occurred in 101 patients given Aranesp and 53 patients given dummy shots. Looked at another way, the risk of suffering a stroke was about 1 percent per year in the placebo group and about 2 percent in those given Aranesp. Results were published online Friday by the New England Journal of Medicine (NEJM). For many patients, this risk will outweigh its potential benefits, the study’s authors concluded.

On a positive note, in the present study, Darbepoetin-α [Aranesp] did reduce the need for transfusions;  297 people on the drug needed them versus 496 of those getting dummy shots. However, there was only a modest improvement in how fatigued people said they felt in the Aranesp group.

For your convenience, you find the abstract of the study be Pfeffer M.A., et al., published at www.nejm.org October 30, 2009 (10.1056/NEJMoa0907845). Please read the full study result at the link provided.

ABSTRACT
Background Anemia is associated with an increased risk of cardiovascular and renal events among patients with type 2 diabetes and chronic kidney disease. Although darbepoetin alfa can effectively increase hemoglobin levels, its effect on clinical outcomes in these patients has not been adequately tested.

Methods In this study involving 4038 patients with diabetes, chronic kidney disease, and anemia, we randomly assigned 2012 patients to darbepoetin alfa to achieve a hemoglobin level of approximately 13 g per deciliter and 2026 patients to placebo, with rescue darbepoetin alfa when the hemoglobin level was less than 9.0 g per deciliter. The primary end points were the composite outcomes of death or a cardiovascular event (nonfatal myocardial infarction, congestive heart failure, stroke, or hospitalization for myocardial ischemia) and of death or end-stage renal disease.

Results Death or a cardiovascular event occurred in 632 patients assigned to darbepoetin alfa and 602 patients assigned to placebo (hazard ratio for darbepoetin alfa vs. placebo, 1.05; 95% confidence interval [CI], 0.94 to 1.17; P=0.41). Death or end-stage renal disease occurred in 652 patients assigned to darbepoetin alfa and 618 patients assigned to placebo (hazard ratio, 1.06; 95% CI, 0.95 to 1.19; P=0.29). Fatal or nonfatal stroke occurred in 101 patients assigned to darbepoetin alfa and 53 patients assigned to placebo (hazard ratio, 1.92; 95% CI, 1.38 to 2.68; P<0.001). Red-cell transfusions were administered to 297 patients assigned to darbepoetin alfa and 496 patients assigned to placebo (P<0.001). There was only a modest improvement in patient-reported fatigue in the darbepoetin alfa group as compared with the placebo group.

Conclusions The use of darbepoetin alfa in patients with diabetes, chronic kidney disease, and moderate anemia who were not undergoing dialysis did not reduce the risk of either of the two primary composite outcomes (either death or a cardiovascular event or death or a renal event) and was associated with an increased risk of stroke. For many persons involved in clinical decision making, this risk will outweigh the potential benefits. (ClinicalTrials.gov number, NCT00093015 [ClinicalTrials.gov] .)