Shares of Amgen Inc. jumped 12 percent on Thursday, a day after the biotech reported a vastly improved third quarter and raised its full-year outlook.

The Thousand Oaks drug maker reported after Wednesday’s market closed that it earned $1.16 billion ($1.09 per share) for the quarter ended Sept. 30, compared with $201 million (18 cents) in the same period last year when the company took acquisition and restructuring charges totaling nearly $900 million.

Revenue grew 7 percent to $3.88 billion on increased sales of Neulasta, which prevents infections in chemotherapy patients, and Enbrel, which is used to treat rheumatoid arthritis.

Net revenue from the company’s troubled, but still best-selling anemia drug, Aranesp, grew 3 percent to $845 million. It would have been down 8 percent if favorable accounting and exchange adjustments had been excluded. U.S. sales of Aranesp, which has had safety warnings added to its label, fell 12 percent.

Amgen said its adjusted earnings excluding a one-time acquisition and restructuring cost taken last quarter would have totaled $1.23 per share, 14 percent better than last year’s adjusted figure.

Analysts polled by Thomson Reuters on average had only expected adjusted earnings of $1.08.

Amgen raised its full-year 2008 guidance to between $4.45 and $4.55 per share, compared to an earlier forecast of $4.25 to $4.45. Analysts have been expecting $4.38.

Amgen shares gained $5.85 to close at $55.55 Thusday on the Nasdaq.