NEW YORK (CNNMoney.com) -- Amgen Inc. reported a surge in third-quarter earnings, beating Wall Street's forecast.

Amgen (down $0.58 to $73.37, Charts), the world's biggest biotechnology company, said adjusted earnings per share, excluding stock option expenses and other expenses, jumped 22 percent to $1.04, up from 85 cents during the same period last year.

The biotech also reported a 15 percent jump in adjusted net income, excluding stock option expense and other expenses, to $1.2 billion, and a 15 increase in sales, to $3.6 billion.

Analysts interviewed by Thomson First Call had forecast a 15 percent jump in third-quarter earnings and sales, to 98 cents earnings per share and $3.6 billion. Amgen matched the sales forecast.

Shiv Kapoor, analyst for Montgomery & Co., said the company managed to beat earnings expectations because its tax rate was lower than usual.

Kapoor said the expected sales increase was driven by Aranesp, a treatment for anemia and kidney disease, which appears to be taking market share from Johnson & Johnson's (up $0.48 to $69.10, Charts) Procrit. Aranesp sales soared 27 percent to $1.07 billion, from the third quarter, 2005.

Combined sales of Neulasta and Neupogen, drugs used with chemotherapy to fight infection, jumped 13 percent to nearly $1 billion in the third quarter. Sales of anemia treatment Epogen edged up 6 percent to $633 million. North American sales of Enbrel, a treatment for rheumatoid arthritis, increased 6 percent to $705 million.

Amgen, based in Thousand Oaks, Calif., has seen its stock price drop 6 percent this year, but the company recently received some good news.

A federal court in Los Angeles denied the Swiss drugmaker Roche Holding AG's (Charts) attempt to dismiss Amgen's patent lawsuit against it. Amgen can proceed with its lawsuit, claiming that Cera, Roche's experiment treatment for anemia, infringes the patent on the Amgen drug Epogen.

The world's second-largest biotech, Genentech (up $0.14 to $83.30, Charts), topped third quarter expectations with its Oct. 10 report, but has seen a stock price decline of 2 percent year-to-date.

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