This article is part of the Arthritis Archives.
Dateline: October 14, 2000
Warning Issued
On October 10, 2000, Immunex Corporation sent letters to more than 100,000 doctors and pharmacists, issuing a new warning for Enbrel (generic name etanercept). The warning advised doctors to be cautious in prescribing Enbrel to rheumatoid arthritis patients who also have multiple sclerosis, and to look for signs of serious anemia in anyone taking the drug.
Why The Warning Was Issued
Whenever a new warning is issued for a drug, in this case Enbrel, there is understandably concern among people who take the drug. Gathering details and gaining insight into why the warning was issued is important.
Based on adverse events which have been reported since Enbrel was marketed in November 1998, there have been:
- 11 cases of demyelinating diseases (nerve disorders including multiple sclerosis)
- 10 cases of blood cell shortages (including aplastic anemia). 5 of the blood disorder patients died.
Seattle-based Immunex, the company which manufactures Enbrel, said it was not clear whether Enbrel contributed to the adverse events. Although no proof exists of a direct link between Enbrel and the adverse events, Immunex notified doctors and worked with the U.S. Food and Drug Administration (FDA) to prepare the new warning which reflected changes which were made to the drugs U.S. label back in August.
Neither the demyelination disorders nor the blood disorders were reported in clinical trials before Enbrel was approved. The adverse event reports which lead to the new warning are considered "rare", since more than 80,000 people have taken Enbrel since it was approved by the FDA. Last year, the FDA issued a warning after 6 Enbrel users had died of infections.
No evidence exists which would indicate that multiple sclerosis occurs in Enbrel users at a higher rate than in the general population. There have reportedly been studies of two other anti-TNF drugs, however, which suggest that blocking TNF (tumor necrosis factor)may be associated with symptoms of multiple sclerosis. Enbrel is also an anti-TNF drug.
Talk With Your Doctor
Immunex has urged that patients on Enbrel who experience persistent fever, bruising, bleeding, or pallor should seek medical attention since aplastic anemia can be a life-threatening condition. The issuance of the new warning should not cause panic or alarm among patients taking Enbrel or those considering it as a treatment. Patients are being encouraged to discuss the warning with their physicians so they can assess the risk versus benefits of taking Enbrel, the potential for serious adverse events, and how the patient should be monitored while taking the drug.
Related Resources
Sources: Important Enbrel Safety Information, Immunex:;
Arthritis Drug Warning Issued, AP; Immunex Issues New Warning On Arthritis Drug, Reuters; MS And Enbrel Don't Mix, HealthSCOUT
First published: 10/14/2000
