The drugs, Aranesp and Procrit, are used to stimulate red blood cell production in millions of kidney failure and cancer patients as a way to reduce the need for blood transfusions and reduce fatigue.
But evidence that the drugs increase the risk of dangerous blood clots and death in some cancer patients undergoing chemotherapy has lead regulators to slap new warnings and restrictions on their use.
Eight studies, two published within the last year, have suggested the drugs may shorten the life spans of chemotherapy patients who take them. Those studies have also suggested that higher doses geared toward aggressively boosting patients' red blood cells may be more risky.
An analysis of 51 studies published in The Journal of the American Medical Association last month concluded that the use of Procrit, Aranesp, or Epogen in cancer patients was associated with a 10% increased risk of death and a 57% higher risk of dangerous blood clots.
Both Aranesp, made by Amgen, and Procrit, made by a division of Johnson & Johnson, are known as erythropoiesis-stimulating agents (ESAs) because they stimulate the growth of red blood cells.
New Restrictions Urged
The advisory panel voted 13-1 to allow companies to continue marketing ESAs for cancer patients. But they also voted to narrow the drugs' approved uses to patients with terminal cancers. They also urged the FDA to exclude their use in curable breast cancer and head and neck cancers from its approved indications.
"We got a clear message that they felt the drug should still be available, at least in certain oncology patients," said John Jenkins, MD, head of the FDA's Office of New Drugs.
But committee members are "concerned about the risk," he told reporters.
Panelists also urged the agency to step up patient information surrounding the drugs.
"We want to know as soon as possible at what level, if any, these drugs are safe," said Helen Schiff, a patient representative on the panel.
In a statement, Ortho Biotech, the Johnson & Johnson division that makes Procrit, said the company is "concerned" with the advisory panel's recommendation.
"The company believes that fully informed patients and their physicians should have the choice to use this important medication, which is the only therapeutic alternative to blood transfusions," the company said.
Questions of Dose
The FDA issued "black box" warnings last year cautioning doctors to prescribe only as much ESA to patients as needed to cut the need for transfusion. But the dose has proven to be a moving target in many patients.
Last May, the Center for Medicare and Medicaid Services said it would pay doctors only for ESA treatment designed to achieve a certain red blood cell level. Studies suggest that higher ESA doses increase a patient's risk of death.
Amgen officials echoed that decision Wednesday, saying they would recommend that doctors aim for a targeted red cell level in cancer patients. The company also proposed distributing new safety information to patients and doctors, including a requirement that cancer patients sign a consent form before taking the drug.
"It is clear that the signals that have emerged are important, they need to be addressed. Patients need to be aware," said Paul Eisenberg, MD, of Amgen's global regulatory and safety affairs division.