Amgen Inc. reported higher first-quarter profit, lead by increased sales of its anemia and infection drugs, but forecast that full-year net income for 2007 would be at the low end of expectations.

Amgen reported first-quarter net income of $1.11 billion (94 cents a share) compared with net income of $1 billion (82 cents) for the same period a year ago.

Revenue in the quarter rose 15 percent to $3.69 billion. Analysts were expecting $3.73 billion. Worldwide sales of Aranesp increased 14 percent to $1.02 million, with Aranesp predecessor Enbrel up 11 percent to $730 million. Combined worldwide sales of infection fighters Neulasta and the older Neupogen rose 14 percent to just under $1.02 million.

The Thousand Oaks, Calif.-based biotech’s stock is down more than 18 percent since mid-January when safety concerns about its best-selling anemia drug Aranesp triggered uncertainty about the potential impact on sales. The company now expects full-year adjusted earnings to come in at the low end of its $4.30 to $4.50 per-share guidance range.

Excluding stock option-based compensation, net income rose 19 percent to $1.08 a share in the first quarter on a non-GAAP basis, matching the expectations of analysts polled by Thomson Financial.

Before the announcement, Amgen shares closed up 22 percent to $62.19 on the Nasdaq. The share price gained another 61 cents, or 1 percent, to $62.80 in after-market electronic trading.