Updated from 7:54 a.m. EST

Wall Street was expecting a bullish 2003 forecast from

Amgen

(AMGN) - Get Report

Thursday morning. The world's largest biotech firm didn't disappoint.

Amgen said strong sales across all its drug product lines will help boost earnings next year to $1.70 to $1.80 a share, well above the consensus analyst estimate of $1.65, as polled by Thomson Financial/First Call. The likelihood Amgen would raise guidance ahead of an analyst call Thursday morning was

reported Wednesday by

TheStreet.com

.

Amgen shares opened up 4.8% to $49.55.

On the top line, Amgen forecast 2003 revenue of $7.3 billion to $7.8 billion, including total product sales in the range of $6.7 billion to $7.2 billion. Analysts, on average, were looking for total revenue of just under $7.2 billion.

Amgen finds itself in the enviable position of having three growing product franchises, each billion-dollar-plus sellers. Thursday, the company said 2003 sales for its anemia drug franchise, Epogen and Aranesp, will hit a range of $3.2 billion to $3.4 billion.

While final 2002 sales figures aren't in yet, the two drugs combined look they're headed for mid-20% sales growth in 2003, based on the Amgen forecast. Most of that growth will come from the newer Aranesp, especially as it gains market share in the cancer patient market.

Amgen didn't offer any new guidance on the issue of Aranesp's lower-than-expected rate of Medicare reimbursement for 2003. The company has filed a legal challenge to reverse the decision and the case is now in front of a federal judge.

Amngen is forecasting similarly strong sales growth for its Neupogen/Neulasta drug franchise in the range of $2.l billion to $2.3 billion in 2003. More than half of these sales will be derived from Neulasta, a longer-acting version of Neupogen that can be given once every three weeks instead of once weekly. The drugs help boost white blood cell counts and fight infections in cancer patients.

As for Enbrel, Amgen reiterated its previous 2003 sales forecast of $1.2 billion to $1.4 billion in 2003, which assumes the end to the much-publicized supply constraints that have hampered sales of the rheumatoid arthritis drug. Amgen said the Food and Drug Administration has completed inspections of a new Enbrel manufacturing plant in Rhode Island, with a decision on approval expected shortly.

For the remainder of the current year, Amgen said it expects 2002 earnings in the range of $1.37 a share to $1.39 a share, vs. analyst estimates of $1.37 a share.