Why Amgen's Q1 Results Disappointed Investors

Amgen (NASDAQ:AMGN) has taken investors on a roller coaster ride over the last 12 months. The stock has experienced multiple swings -- up and down -- of 10% or more. And now it looks like another downturn could be on the way.

The company announced its first-quarter results after the market closed on Tuesday. Investors weren't happy with Amgen's report, and the biotech stock fell nearly 4% in after-hours trading. Here are the highlights from Amgen's first-quarter update.