Updated from 5:21 p.m. EDTAmgen ( AMGN), the world's No. 2 biotech concern by market cap, saw its second-quarter earnings decline year over year, but that was mainly because of the acquisition of the drug developer Abgenix. As a result of the April transaction, Amgen's quarterly net income was $14 million, down from $1 billion last year. On a per-share basis, Amgen earned 1 cent a share, compared with 82 cents a year ago. The difference was mostly attributable to the company's writeoff of $1.1 billion in acquired in-process research-and-development expenses, Amgen said Thursday. Excluding certain items, but including 4 cents a share in stock option expenses, Amgen earned $1.01 a share. Total revenue in the second quarter came in at $3.6 billion, up 14% from a year ago. Analysts surveyed by Thomson Financial were looking for a profit of 94 cents a share and sales of just under $3.5 billion for the second quarter. Worldwide sales of Aranesp, a treatment for chemotherapy-induced anemia, rose 26% to $1.1 billion. U.S. Aranesp sales were up 33%, driven by overall market growth as well as market-share gains, Amgen said. Sales of Aranesp took a bite out of revenue from Amgen's other anemia drug, Epogen, which fell 5% to $613 million in the second quarter. Epogen's sales also took a hit from wholesaler inventory changes. Combined worldwide sales of Neulasta and Neupogen increased 12% to $1 billion. North American sales of the psoriasis and rheumatoid arthritis drug Enbrel climbed 13% to $724 million, an advance that was driven by increased demand and a 4.9% U.S. price increase in May. Still, sales growth was tempered by competition and slower-than-expected dermatology segment growth, the company said. Looking ahead, Amgen increased its full-year earnings guidance by 15 cents to between $3.75 and $3.85 a share, excluding stock option expenses. During a conference call, the company lifted its full-year revenue estimates to between $14 billion and $14.3 billion from its previous guidance of $13.9 billion to $14.4 billion.