Amgen Inc.’s popular anemia drug Aranesp has been dropped from Medicare plan coverage by Noridian Administrative Services LLC because of safety concerns, the Wall Street Journal reported Tuesday.

Aranesp is Amgen’s best-selling drug with sales topping $4 billion in 2006. It is prescribed to battle anemia associated with chemotherapy and kidney dialysis.

William Mangold, medical director at Noridian, said the company would no longer pay for use of the drug in the treatment of anemia or cancer, which is an off-label use of the drug. Aranesp was approved by the Food and Drug Administration to treat chemotherapy-related anemia and anemia in kidney disease.

Last week, the Security and Exchange Commission’s Atlanta District Office asked Amgen to provide information and documents about a Danish study released earlier this year that found cancer patients taking Aranesp had a more probable recurrence of their tumors than those not taking the drug.

Amgen said it notified the Food and Drug Administration but didn’t report the results publicly.

Shares in Amgen closed up 13 cents but dipped 10 cents in after-market trading to $62.20 Tuesday.