Earlier today the US Food and Drug Administration (FDA) issued new safety information and labelling for three drugs used to treat anemia.
The drugs affected, known as erythropoiesis-stimulating agents or ESAs, are darbepoetin alfa (brand name Aranesp) and two epoetin alfa brands (Epogen and
Procrit). All three brands are made by Amgen Inc of Thousand Oaks, California. Procrit is also marketed and distributed by Ortho Biotech LP, a subsidiary
of Johnson & Johnson.
ESAs are genetically engineered versions of the human protein erythropoietin that increases red blood cells (hemoglobin) and is made in the kidneys.
The new product labelling covers updated warnings, boxed warnings and changes to dosing instructions.
Doctors and patients are urged to weigh the risks of taking ESAs versus the risk of transfusion. The boxed warning advises doctors to keep an eye on red
blood cell count and to adjust the ESA dose so the patient takes the minimum amount needed to avoid a blood transfusion.
Director of the FDA's Center for Drug Evaluation and Research, Dr Steven Galson, said that the FDA "is in the process of re-evaluating the safety of Aranesp,
Epogen, and Procrit on the basis of the results of recent clinical studies."
These studies showed that patients with chronic kidney failure who take higher than the recommended dose of ESAs carry an increase risk of death, strokes,
heart attacks and blood clots.
Also, patients with cancer who were not receiving chemotherapy and took recommended doses of ESAs carried an increase risk of death, while patients who took
ESAs at the recommended dose after orthopedic surgery carried an increased risk of blood clots.
Dr Galson added that the new information reflects the findings of these studies and applies to all ESAs which have the same method of increasing hemoglobin.
He also announced there would be another meeting in May when the Oncologic Drugs Advisory Committee (ODAC) will look at the evidence and they may suggest
further changes to the labels.
The safety labelling for these drugs has been revised three times since 1997 to reflect new safety concerns.
All three drugs are approved by the FDA to treat patients whose anemia is caused by chronic kidney failure or chemotherapy treatment for cancer.
In addition, Epogen and Procrit are approved for patients who are about to have major surgery to minimise need for blood transfusions and for HIV patients
who have anemia due to zidovudine therapy.
However, no ESAs have been approved to treat the symptoms of anemia, including fatigue, in cancer, surgical and HIV patients.
Anemia, the most common blood disorder, is a deficiency in red blood cells or the oxygen-carrying hemoglobin within them. Reduced ability of the blood to
transport essential oxygen to cells is called hypoxia which has varying degrees of severity.
Anemia is usually caused by one of three things: excessive loss of blood, excessive destruction of blood cells, or deficiency in red blood cell production. Iron deficiency
is another way that menstruating women can get anemia since it reduces production of red blood cells.
Click here for more information on Anemia (wikipedia).
Written by: Catharine Paddock
Writer: Medical News Today
Publication Date: 2007-03-09 18:00