(The Los Angeles Daily News) -- Biotechnology giant Amgen Inc. has submitted additional clinical data about Enbrel to U.S. regulators, a move that could eventually broaden the rheumatoid arthritis drug's marketing breadth.

While the drug is already approved to treat patients with moderate to severe rheumatoid arthritis, the Thousand Oaks-based company would like the label to include that "Enbrel showed an improvement in physical functioning."

"Enbrel will be facing stiff competition from D2E7 (a drug developed by Abbott Laboratories) in the near future," said Jennifer Chao, analyst with RBC Capital Markets in New York. "And the strategy is to try to get as broad of a label as possible."

Last month, Amgen applied for regulatory approval of an Enbrel manufacturing facility in Rhode Island - an important step to alleviate shortages of the arthritis drug. The 250,000-square-foot facility stems from Amgen's $14 million purchase of Seattle-based Immunex Corp., which received approval from U.S. regulators in July.

The surge in Enbrel's popularity has ultimately led to its scant supply. Dr. Daniel Burge, a vice president of clinical research at Amgen, said the data submitted to the Food and Drug Administration prove Enbrel's efficacy.

"And we frequently hear from patients that they've been able to resume many of their daily activities, such as brushing their hair or picking up their child, that had become impossible due to their rheumatoid arthritis," Burge said.

Last year, Enbrel sales accounted for $800 million, but with Amgen's marketing backing the product, the drug could generate sales of $3 billion by 2005. Immunex projected that Enbrel sales would surge as high as $4 billion by 2005.

"Helping Enbrel even more is that it has a proven track record," Chao said. "And it's important to maintain the drug's success."

Amgen shares fell 36 cents to close at $43.70 on the Nasdaq market Thursday.

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