Amgen Inc. said improved sales of its anti-infection drugs boosted its first-quarter profit by 15 percent, but warned that health care reform measures likely will dampen its fiscal 2010 results.

The Thousand Oaks biotech reported net income of $1.17 billion ($1.18 per share) compared with $1.02 billion (98 cents) a year earlier. Revenue climbed 9 percent to $3.59 billion.

Excluding one-time costs, Amgen would have earned $1.30 per share. Analysts surveyed by Thomson Reuters expected per-share profit of $1.23 on revenue of $3.65 billion.

Sales of Amgen’s anemia franchise, which plunged on safely concerns in 2007, rebounded 5 percent overall to $1.25 billion. Epogen sales jumped 10 percent while Aranesp sales were flat.

Amgen said sales of Neupogen and Neulasta, which prevent infection for patients undergoing chemotherapy, rose 10 percent to $1.18 billion, both due to a price increase and greater demand overseas. Sales of Enbrel, a rheumatoid arthritis and psoriasis drug, rose 6 percent to $804 million.

The company now expects that the new federal health care reform legislation will cut $200 million to $250 million from fiscal 2010 results. It expects adjusted profit will come in toward the lower end of its forecast of $5.05 to $5.25 per share on sales of $15.1 billion to $15.5 billion.

Amgen is expecting U.S. approval of its osteoporosis drug Prolia to come by late July. The drug also is being evaluated in the European Union.

“We are off to a good start in 2010 with solid first-quarter results,” said Chief Executive Kevin Sharer in a press release. “We are optimistic about Prolia in the U.S. and EU and will take appropriate steps to manage the impact of the new U.S. health care reform law.”

Amgen shares closed down 55 cents, or 1 percent, to $58.16 on the Nasdaq.