In a letter sent last week to medical professionals and posted by the U.S. Food and Drug Administration (FDA), drug maker Amgen warned of an elevated risk of fatalities associated with the use of their anemia drug, Aranesp (darbepoetin alfa), in cancer patients. Amgen conducted a clinical trial to test the safety and efficacy of Aranesp on patients whose anemia was caused by cancer, hoping to expand the approved usage of the drug to include that indication.
Amgen warned that “Aranesp was ineffective in reducing RBC [red blood cell] transfusions in patients with cancer who have anemia that is not due to concurrent chemotherapy. In addition, this study showed higher mortality in patients receiving Aranesp.” The Phase 3, double-blind, randomized, placebo-controlled study included 989 patients with active cancer and low hemoglobin levels, but who weren’t receiving chemotherapy or radiotherapy. In the 16-week treatment phase, more deaths were reported in the Aranesp treatment group (26 percent) than the placebo group (20 percent).
Amgen also notes, “Aranesp is not approved for use in this population. Aranesp is approved for the treatment of patients with anemia, which is caused by chemotherapy treatment of their malignant disease, rather than the underlying malignant disease itself.” However, corporate estimates say that approximately 10 to 12 percent of all Aranesp sales are for that exact off-label (unapproved) usage. The clinical trial was set up in order to get the drug approved for use in those patients whose anemia was caused by cancer directly (as opposed to chemotherapy).
Epogen, Amgen’s other anemia drug, has come under fire as well. In November, two studies in the New England Journal of Medicine called into question the overuse of anemia drugs in the treatment of kidney patients. Scientists have found that anemic kidney patients are susceptible to heart problems or death when aggressively treated with these drugs. The drugs are intended to boost hemoglobin in anemic patients, but the increase in hemoglobin is associated with other serious risks.
Epogen has also been under attack by Congress because of the strain it places on Medicare. Anemia drugs are currently Medicare’s largest drug expenditure. Epogen and Aranesp account for approximately $6 billion in revenue and $2 billion in profit for Amgen.