(CN) - The arthritis drug Enbrel caused a woman with Down syndrome to develop life-threatening blood conditions and die of a cerebral hemorrhage, her mother claims in court.
Glenda Chatman filed an eight-count complaint against Immunex, Amgen and Pfizer in the Circuit Court of Talladega County, Ala.
She claims her daughter, Kelly, who had Down syndrome and was prescribed and given Enbrel between January and December 2010, and soon developed thrombocytopenia, a disorder involving a reduced platelet count, and other complications.
Kelly died on Sept. 23, 2011, from a cerebral hemorrhage caused by those complications, according to the complaint.
"At the time Kelly Chatman was treated with Enbrel she was an adult female but suffered from Down syndrome and was physically and mentally dependent upon the plaintiff, Glenda Chatman, for her care and support," the complaint states.
The complaint does not reveal why Kelly was prescribed the arthritis drug.
Kelly was allegedly hospitalized numerous times in 2010 for her platelet disorder, but treatment by hematologists and rheumatologists could not save her.
Enbrel (etanercept) hit the market in 1998 and is one of a class of other tumor-necrosis-factor blocking drugs, according to the Amgen's website.
The drugmaker says Enbrel was the first biologic approved for rheumatoid arthritis and has "over 10 years of continuous safety data in patients with moderate to severe rheumatoid arthritis."
Amgen is one of the world's premier developers and manufacturers of biologic medicines.
Antibodies, interleukins and vaccines are all biologics in that they are made from a living organism or its products, and used to prevent, diagnose or treat of cancer and other diseases.
Chatman says Enbrel's known and unwanted side effects include life-threatening autoimmune and platelet disorders.
Amgen mentions "blood problems (some fatal)" on its webpage for Enbrel, as well as in its official prescription information publication.
Though blood problems were presented in Amgen's Controlled Clinical Trials of the drug, the drugmaker listed it as of several adverse reactions reported during post-approval use of Enbrel in adults and pediatric patients," according to the prescription information.
That document also notes "rare (< 0.1%) reports of pancytopenia, including very rare (< 0.01%) reports of aplastic anemia, some with a fatal outcome, have been reported in patients treated with Enbrel."
The most common adverse reaction among patients with rheumatoid arthritis is infection, according to the paper.
The safety information page for Enbrel on the Food and Drug Administration's MedWatch does not mention blood-related warnings.
Amgen did not return a request for comment.
Chatman is suing for wrongful death, negligence, liability under the Alabama Extended Manufacturer's Liability Doctrine, strict product liability, failure to warn and breach of warranty.
She seeks $5 million in damages and is represented by Frank Hanson of Smith & Hanson in Fairfield, Ala.
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