More Trouble for Amgen, as Enbrel Gets Stronger Infection WarningsMar 18, 2008 | Parker Waichman LLP
Enbrel, a popular treatment for rheumatoid arthritis and psoriasis, is getting stronger warnings about serious infections associated with its use. Yesterday, Amgen and Wyeth added the strongest U.S. Food and Drug Administration (FDA) warning—the “black box”—to the prescribing information Enbrel. The warning will highlight the risk of infections, including tuberculosis. The information, which is currently in boldface, must now be highlighted inside a boxed border Amgen and Wyeth said.
In global studies of over 20,000 patients taking Enbrel, tuberculosis was observed in about 200 people. Approximately 14,000 Americans were diagnosed with tuberculosis last year. Tuberculosis is a bacterial lung infection, and according to the federal Centers for Disease Control and Prevention (CDC), people with weakened immune systems are more likely to contract the disease. Enbrel and other medicines in the same class work by blocking a type of immune system protein. The prescribing information warns about new cases and reactivated latent infections, the companies said.
In addition, Moody’s Investors Service placed Amgen’s long-term and short- term debt ratings under review for a possible downgrade. The rating action follows last week’s recommendation by an FDA advisory panel for additional restrictions on the use of Amgen’s anemia drugs, including its top-seller Aranesp, in cancer patients, Moody’s said yesterday. Interim results from a recent, independent study involving breast cancer patients found Aranesp did not enhance the effect of chemotherapy prior to surgery. The study involved over 700 patients and evaluated whether Aranesp prevented anemia and augmented the therapeutic effects of chemotherapy regimens.
Amgen also reported that participants who received Aranesp had numerically more deaths and reports of tumor growth than control group patients. Preliminary, long-term, follow-up data revealed more deaths in the group receiving Aranesp, with more tumor progression events versus the control group. The entire drug class has been under a microscope as debates rage over whether anemia drugs increase the risk of heart attack and stroke, and whether they may play a role in fueling the growth of cancer. Aranesp labels were updated to include revised dosage guidelines and information on the drugs’ cardiovascular side effects following the FDA’s ordering of a black box warning about cardiovascular problems and other safety.
About $11.2 billion of Amgen’s A2 long-term and Prime-1 short-term rated debt will be affected, the rating agency said. Aranesp sales fell at least 50 percent last year after the medicines were tied to greater risks of heart attacks, stroke, and death at high doses. Reduced demand caused Amgen to lose $29 billion in market value last year. “Amgen’s key credit ratios may not have sufficient cushion to absorb any further decline in Aranesp sales at the current rating level,” Moody’s said in the statement. Enbrel was the world’s fifth-best-selling drug last year, with $5.28 billion in revenue. Wyeth and Amgen’s drug competes with Johnson & Johnson’s Remicade, which generated $5.21 billion.
Enbrel, an injection, is designed to work by soaking up an excess inflammatory protein called TNF. The protein can attack the skin and lead to psoriasis, or it can attack joints, causing rheumatoid arthritis, researchers say.