According to new research, the anti-anemia drugs Aranesp, Epogen and Procrit not only increase the risk of blood clots, but they also do not appear to be doing what they were designed to do.
A study published on-line Tuesday by the Journal of the National Cancer Institute suggests that Epogen, Procrit and Aranesp side effects double the risk of patients developing blood clots. The results also indicate that the drugs, designed to reduce the number of blood transfusions needed during chemotherapy, have resulted in no detectable drop in the number of blood transfusions performed since they were introduced.
Researchers from New York-Presbyterian Hospital and Columbia University Medical Center conducted a 10-year study of 55,000 cancer patients, monitoring the effects of a class of drugs known as erythropoiesis-stimulating agents (ESAs). The study found a doubling of the risk of blood clots by patients using the drugs. Researchers also discovered that even though the use of the drugs increased by a factor of 10 between 1991 and 2002, there was no detectable decrease in the rate of blood transfusions among the same patients.
Amgen’s Aranesp (darbepoetin alfa) and Epogen (Epoetin alfa) and Johnson and Johnson’s Procrit (Epoetin alfa) are prescribed to patients with kidney disease, anemia, HIV and cancer to stimulate bones to increase the production of red blood cells. They are also prescribed to patients preparing to undergo major non-heart surgery to reduce the number of transfusions such patients must receive.
In 2008, Aranesp sales were $3.1 billion, and Procrit accounted for $2.46 billion in sales. Researchers estimated that by 2002, the drugs were being prescribed to nearly half of all cancer patients.
Sales have fallen in recent years, following research that suggested the drugs increase the risk of serious and potentially life-threatening health problems. 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.
Late last month, a different study was published in the New England Journal of Medicine with results that indicate that diabetes patients on Aranesp faced twice the risk of stroke and did not reduce their risk of death or cardiovascular event while taking the drug.
Researchers in this latest study say that the results raise questions on whether the risk ESAs outweighs the benefits. They also suggested that there need to be additional studies that look for long-term toxicity in patients.