The world's biggest maker of biologic drugs said Tuesday that net income was $1.02 billion, or $1.33 per share, up from $788 million or $1.01 per share, a year earlier.
Excluding one-time items, the maker of osteoporosis drug Prolia said earnings amounted to $1.39 billion, or $1.82 per share. Analysts were expecting $1.69 per share.
Revenue rose 13 per cent to $5.01 billion. Analysts expected $4.81 billion, according to FactSet.
"A large part of the beat was the low tax rate," noted Edward Jones analyst Judson Clark, who has a "Hold" recommendation on Amgen's stock after its big run-up early last year.
In after-hours trading following the release of the results, Amgen shares fell 70 cents to $120, after rising $1.84, or 2.2 per cent, to $120.70 in regular trading.
Sales were led by Neulasta and Neupogen for boosting infection-fighting white blood cells, up 8 per cent to a combined $1.41 billion. Sales of immune disorder drug Enbrel rose 3 per cent to $1.12 billion.
Six other established drugs saw sales increases of 10 per cent or more. Those included Prolia, touted in ads by actress Blythe Danner.
Only Aranesp had lower sales, down 4 per cent to $180 million due to lower demand.
CEO Bob Bradway told analysts on a conference call that sales were "strong in the U.S. and once again, we were one of the few companies growing revenues in Europe."
He added that expanding into new regions is key to Amgen's strategy and that the end of a co-promotion deal with Pfizer Inc. on Enbrel should bring Amgen an extra $800 million this year.
Sales were boosted by Amgen's $9.7 billion purchase of Onyx Pharmaceuticals Inc. on Oct. 1, part of Amgen's strategy to become a major player in the market for pricey cancer drugs. Onyx's Kyprolis, a treatment for the blood cancer multiple myeloma, posted sales of $73 million.
Also Thursday, Amgen said a late-stage patient test of evolocumab, for stubbornly high cholesterol, met the study's two main goals for reducing the absolute level of bad, or LDL, cholesterol and for the average per cent reduction. It was tested along with a statin, the widely used cholesterol drugs that include Lipitor. Amgen plans to disclose details later.
The company, based in Thousand Oaks, Calif., forecast 2014 adjusted earnings per share of $7.90 to $8.20 and revenue of about $19.4 billion. That compares with the average analyst forecast for annual earnings per share of $8.17 on revenue of $19.51 billion.
Clark is concerned growth could slow, amid price hikes fueling much of the higher revenue and what he called a "disappointing" forecast.
For 2013, Amgen earned $5.08 billion, or $6.64 per share, on revenue of $18.68 billion.
Linda A. Johnson can be followed at http://twitter.com/LindaJ_onPharma