Amgen

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said people with the inflammatory disease ankylosing spondylitis showed a sustained improvement in their symptoms over three years while being treated with Enbrel.

Patients received therapy for 148 to 160 weeks. Signs and symptoms of the condition, along with spinal mobility and physical function, improved during the term of the study.

The results were consistent with the previous 24-week data on the drug that were used to support its 2003 approval. The longer-term findings were reported at a meeting of the American College of Rheumatology Monday.

Separately, Amgen said nine years of data on rheumatoid arthritis patients getting Enbrel revealed that some measures of the drug's effectiveness were maintained throughout the study.

Shares fell 81 cents, or 1.1%, to $72.65.