Amgen Inc. reported Tuesday that its profits rose 38 percent, beating analysts’ expectations for the second quarter due to strong sales of its anemia and arthritis treatments. The Thousand Oaks-based biotechnology company also raised its financial outlook for the year.

Amgen reported net income of $1 billion (82 cents per diluted share) for the second quarter ended June 30, compared with $748 million (57 cents) for the like period a year earlier. Revenue rose 23 percent to $3.2 billion from $2.6 billion in the comparable period of the prior year.

Amgen said its second-quarter earnings would have been $1.1 billion (88 cents per diluted share), versus $809 million (62 cents) in the year-earlier period, if it had not incurred charges related to the acquisitions of Immunex Corp. and Tularik Inc. Revenue was not affected.

Analysts had forecast earnings of 72 cents per share on revenue of $3 billion.

Total product sales for the quarter rose 26 percent to $3.1 billion, led by Aranesp, which is used to treat anemia in cancer and kidney dialysis patients. Worldwide sales of Aranesp increased 36 percent to $837 million, while U.S. sales rose to $536 million from $380 million the year before.

Sales of Epogen edged up 2 percent to $647 million from $633 million in the year-ago period, reflecting increased usage of Aranesp, the company said. Worldwide sales of Enbrel, for arthritis and psoriasis, jumped 45 percent to $639 million. Worldwide sales of Neulasta and Neupogen rose to $587 million and $312 million, respectively.

Due to the strong momentum that continued into the second quarter, the company said it now expects to earn between $3.10 and $3.20 per share in 2005, up from previous guidance of $2.80 to $2.90 issued three months ago.