Excessive use of Anemia Drugs could be Fatal - FDA

The excessive use of popular anemia drugs poses the risk serious health problems, which can sometimes be fatal for patients with cancer and kidney disease, according to Food and Drug Administration that issued stern new warnings on Friday for doctors.

The US health agency yesterday warned doctors to carefully prescribe the widely used anemia drugs as they can worsen tumors and increase the risk of death in some patients.

The popular drug brands under the threat are Aranesp, Epogen, made by Amgen Inc., and Procrit, sold by Johnson & Johnson, to treat patients undergoing cancer treatment and those with kidney failure.

These anemia drugs, which are genetically engineered versions of a natural protein, erythropoietin-stimulating agents (ESAs), which stimulate the number of red blood cells, will get "black-box" warnings about serious health risks including risk of dangerous blood clots and early death if used too aggressively in some patients, the FDA said.

The new stern warning will note that when the drugs, at issue, are given with a red blood cell count greater than 12 grams/deciliter, they can pose the higher risk for death, blood clots, as well as serious strokes and heart attacks.

"The new warning tells physicians to monitor red blood cell levels and to adjust the dose of these drugs to maintain the lowest red cell level needed to avoid blood transfusions," said Dr. Richard Pazdur, the head of the FDA's Office of Oncology Drug Products.

Besides re-evaluating the safety of drugs, the agency has urged physicians to use the lowest doses needed to help patients avoid blood transfusions, and even telling researchers to consider ending clinical trials involving the drugs. “There are many questions that need to be looked at, including additional clinical trials,” Pazdur added.

A panel of agency advisers is due to discuss the drugs at a May 10 meeting.

The recent studies found that higher-than-approved doses of the drugs increased the risk of death, blood clots, strokes and cardiovascular events in patients with chronic kidney failure, while it led to rapid tumor progression in people with advanced head and neck cancer.

Anemia is a common side effect with certain forms of kidney disease, especially for patients undergoing dialysis, and for cancer patients undergoing chemotherapy.

The drugs targeted by the FDA are actually approved to prevent blood transfusions in kidney failure and cancer patients, but health official suggested that doctors have increasingly used ESAs, the protein produced in the kidneys, to stimulate red blood cells higher than the level needed to avoid transfusion in an effort to prevent fatigue in patients.

Pazdur said that beyond the use of ESAs to prevent blood transfusions, the drugs have been advertised as a way for cancer patients to feel better during treatment. "The FDA reminds physicians that erythropoiesis-stimulating agents are approved for the reduction in red cell transfusion. For oncology patients, these products have not been shown to improve or relieve symptoms of anemia or to improve quality of life," he said.

The three drugs, Aranesp, Epogen and Procrit, are huge sellers, with combined last year U.S. sales of $10 billion, according to IMS Health Inc.

Aranesp and Epogen together generated 47 percent of the company's revenue in 2006, while Procrit, New Brunswick, New Jersey based Johnson & Johnson's version of Epogen, had $3.18 billion in sales.

The Thousand Oaks, California-based biotechnology company Amgen sold $4.1 billion worth of Aranesp last year, making it company’s biggest-selling product.

Amgen shares slipped $1.31, or 2.1%, to $60.86 at in the evening trading at NASDAQ Stock Market, while shares of Johnson & Johnson were up 42 cents to $62.14 in New York Stock Exchange composite trading.