THOUSAND OAKS, Calif. ( TheStreet) -- Amgen (AMGN - Get Report) posted adjusted earnings for the first quarter that grew 22% and beat Street expectations. However, Amgen's bottom-line beat was driven largely by tax benefits and fewer outstanding shares but not revenue, which fell short.
Amgen shares are down 5% to $107.25 in after-hours trading, following the release of earnings.
Total revenue in the quarter grew 5% to $4.24 billion, below Street expectations of $4.37 billion. Almost across the line, all of Amgen's major products either just met consensus estimates or under-performed expectations.
Amgen's adjusted earnings for the March quarter were $1.96 per share -- beating the Street's consensus of $1.84 per share. A federal audit for tax years 2007-2009 significantly reduced the company's tax rate for the quarter, thereby boosting profits.For guidance, Amgen said it expects 2013 adjusted earnings to be above the midpoint of the range of $7.05 to $7.35 per share, or slightly above the current consensus of $7.20 per share. But again, on all the all-important top-line, Amgen merely reiterated previous guidance calling for revenue in the range of $17.8 billion to $18.2 billion. -- Reported by Adam Feuerstein in Boston. Follow @AdamFeuerstein