In 2005, the drugs darbepoetin and epoetin, commonly used by patients who must undergo dialysis, accounted for almost 20% of the $13 billion spent on the Medicare Part B drug plan, and total sales for these drugs worldwide topped $9 billion.
Amgen manufactures and markets darbepoetin as Aranesp, and epoetin is sold under the names Procrit and Epogen. But Procrit is distributed by Ortho Biotech Products, a Johnson & Johnson subsidiary. There are no generic versions of these medications.
The drugs are among the top sellers for both companies. Amgen's Epogen and Aranesp combined sales were $6.6 billion in 2006, nearly half of the company's total revenues. Johnson and Johnson's revenues were $3.2 billion in 2006, making it the company's second-biggest-selling drug, according to Forbes.com on March 21, 2007.
The drugs are man-made versions of erythropoietin, a hormone normally produced in the kidneys, and belong to a class of drugs known as Erythropoiesis Stimulating Agents. ESA's are used to treat anemia in raising hemoglobin levels by increasing the number of red blood cells in the body. Anemia's severity is monitored by a patient's hematocrit, the proportion of red blood cells in whole blood, which should stay between 33% and 36%.
According to the FDA, ESAs are approved to treat anemia in patients with chronic kidney failure, patients with cancer whose anemia is caused by chemotherapy, patients scheduled for major surgery to reduce potential blood transfusions, and for the treatment of anemia due to zidovudine therapy in HIV patients.
But Aranesp, Epogen, and Procrit are being administered "off label" for uses and in doses not approved by the FDA. For instance, an Amgen vice president recently estimated that about 10% to 12% of Aranesp sales are for the unapproved use of treating "anemia of cancer" in patients who are not undergoing chemotherapy.
A recent company study conducted to support FDA approval for using the drug to treat "anemia of cancer" in patients with cancer in remission who were not undergoing chemotherapy, revealed that Aranesp actually increased the risk of death in these patients.
The February 2, 2007, "Cancer Letter ," a newsletter for cancer professionals, warns, "If the findings of the recently reported study hold up, more than one in 10 Americans getting Aranesp without chemotherapy has no chance of benefiting from the agent and could be harmed or killed by it, experts say."
The report estimated that up to 12% of the use of ESAs in the US was for this condition.
After reviewing the results of this study and several others, on March 9, 2007, the FDA announced that black box warnings would be added to the labels for all ESAs and recommended using the lowest possible dose to raise the hemoglobin concentration to the lowest level.
The FDA-approved labeling for the drugs says patients should have a hemoglobin level of 10-12 grams per deciliter of blood, and patients are considered to need treatment if their levels fall below 10 grams.
During a press briefing, Dr Richard Pazdur, director of the FDA's Office of Oncology Drug Products at the Center for Drug Evaluation and Research, said the black box warning was being added based on the results of several recently reported clinical trials.
Dr Karen Weiss, deputy director of the Office of Oncology Drug Products, said the FDA became concerned after receiving the results from several trials evaluating the aggressive use of ESAs to raise hemoglobin levels higher than listed on their approved labels.
In the March 10, 2007 Wall Street Journal, Dr Weiss was quoted as saying, the "bulk of the data that has raised concerns" came when patients were given higher doses, whether they were experiencing anemia from kidney disease or cancer treatment.
The evidence shows that "this type of strategy is not beneficial and, in fact, has some evidence of harm," she said.
On March 9, 2007, the FDA also issued a public health advisory based on the results of a number of studies and warned doctors treating patients with kidney disease or cancer not to push hemoglobin levels over 12 grams per deciliter of blood.
The FDA noted a higher chance of death and an increased rate of tumor growth in cancer patients with advanced head and neck cancer receiving radiation therapy and in patients with metastatic breast cancer receiving chemotherapy, when ESAs were given to maintain levels of more than 12.
There was also a higher rate of death reported, but no fewer blood transfusions, when ESAs were given to patients with cancer and anemia who were not receiving chemotherapy.
A higher chance of death and an increased number of blood clots, strokes, heart failure and heart attacks were found in patients with chronic kidney failure when ESAs were given to raise hemoglobin levels of more than 12.
The Advisory warned that a higher risk of blood clots was also reported in patients who were scheduled for major surgery and received ESAs.
The FDA pointed out that ESAs are not approved for treatment of the symptoms of anemia, such as fatigue in patients with cancer, surgical patients and patients with HIV.
The drug makers have been using direct-to-consumer advertising to increase sales with cancer patients by claiming the drugs could restore energy and reduce fatigue in patients undergoing chemotherapy. But the FDA says there has never been any evidence to support claims that ESAs could increase energy or ease fatigue in patients undergoing cancer treatment.
In recent months, Congress has been investigating Medicare reimbursement policies that guarantee dialysis clinics a 6% profit for administering ESAs, since it became apparent that patients are being given higher doses than needed. Critics say any deal that allows for cost plus payments comes with a built-in incentive to provide unnecessary services.
On October 24, 2006, the Boston Globe reported that dialysis clinics are also increasing profits by administering ESAs intravenously instead of by injection, and about 95% of the patients receive the drugs intravenously.
Clinics could use 30% less, the Globe says, because when ESAs are injected they stay in the system longer and require a lower dose. A 2004 analysis found patients injected with the drugs were given 21% less, for a potential total savings of about $375 million.
The two clinic chains that dominate the dialysis industry are DaVita, with over 1,200 clinics, and Fresenius Medical Care, with about 1,500. According to the Globe, the clinics claim the intravenous method is more convenient because patients are already hooked up to IVs for dialysis.
Critics think differently. "The industry is incentivized to use intravenous because they make a profit margin on every unit they administer," said Dr Peter Crooks, who oversees dialysis for 3,000 patients for Kaiser Permanente where most patients receive injections.
In an April 11, 2007 report, Bernstein Research estimates that dose volume in renal patients could fall as much as 25% if doctors abide by the new black box warning and insurers refuse to pay for the drugs in patients with hemoglobin levels over 12.
On November 17, 2006, the British journal Lancet reported that about half of all dialysis patients have hemoglobin levels above what the FDA considers safe, and about 20% of patients experience dangerously high levels, creating a risk for heart attack and stroke.