Fresh concerns about Amgen's anemia drugs

Anemia drugs sold by Amgen Inc. took another hit Thursday when government regulators said two new studies indicated that the drugs may increase the risk of death in some patients.

Based on the studies, the Food and Drug Administration may further restrict the use of the drugs, which already carry the agency's strictest "black box" warning.

"This new information further underscores the safety concerns," said Janet Woodcock, acting director of the FDA's Center for Drug Evaluation and Research. She said the agency "is reviewing these data and may take additional action."

In recent years, six studies have found that the drugs -- marketed by Amgen as Aranesp and Epogen and by Johnson & Johnson as Procrit -- can lead to an increased risk of heart attack, stroke, heart failure and cancer tumor growth in some patients.

Amgen, based in Thousand Oaks, until recently enjoyed an unusually charmed life in the often treacherous biotech industry, with profits and a market value higher than many top-shelf pharmaceutical companies. A large share of the company's fortunes came from Aranesp and Epogen, which accounted for more than half of its net income.

Since the summer, Amgen's stock has fallen to a five-year low and the company has lost $17 billion in market capitalization. It laid off 14% of its employees late last year.

Known as erythropoietin stimulating agents or ESAs, the anemia drugs are bioengineered versions of a natural protein made in the kidney that stimulates bone marrow to produce more red blood cells. Cancer and dialysis patients use injectable ESAs to treat anemia and boost energy.

Fallout from the earlier studies' findings rankled patients and regulators. The FDA added the black box warning last year and the federal Medicare agency followed with limits on what dosages of anemia drugs it will reimburse, affecting the company's sales.

The results of the two most recent research studies appear to reinforce concern that some cancer patients die sooner when taking the drugs than those who don't.

The first involved 733 women who received chemotherapy before undergoing surgery for breast cancer. After three years, 14% of the patients who received Aranesp to treat their anemia had died, compared with 9.8% who didn't receive the drug. Tumors also grew faster in patients receiving Aranesp.

Amgen informed FDA officials about the findings in late November and regulators have been reviewing the data since.