Amgen Inc. (AMGN), the world's largest biotechnology company, said Thursday that first-quarter profit grew 11.8 percent, powered by increased sales of its anemia and chemotherapy drugs and by lower taxes.

Earnings totaled $340.9 million, or 32 cents a share, up from $304.9 million, or 28 cents a share in the same period a year ago. The results met expectations of analysts surveyed by Thomson Financial/First Call.

Revenue in the three months ended March 31 rose to $1 billion, up from $901.6 million in the first quarter of 2001.

Sales of Amgen's most important product, Epogen, an anemia therapy for patients on dialysis, and its next-generation anemia product Aranesp, increased 10 percent to $551 million, but did not meet expectations.

The company said sales dragged slightly when customers began using up old inventory.

Sales of Amgen's products for chemotherapy patients, Neupogen and Neulasta, which are prescribed to cut the risk of infection, rose 21 percent to $355 million.

The firm raised its forecast for future revenue growth, predicting sales would grow in the low 20 percent range this year, up from earlier guidance of growth in the high teens.

On a conference call with analysts, Amgen officials declined to update guidance for earnings until the company completes its $16 billion acquisition of Immunex, which makes the rheumatoid arthritis drug Enbrol. That transaction could close as early as June.

Amgen said results benefited from a lower tax rate of 31 percent during the quarter, compared with a 34 percent rate last year.

Amgen announced its results after the markets closed. In Thursday trading, shares in the company fell 91 cents to $55.20 each.