Regeneron Pharmaceuticals (NASDAQ:REGN) has been on a tear, up more than 750% over the past three years.

Much of that success has to do with one drug in the company's arsenal: Eylea, to treat macular degeneration. Despite going head-to-head against an established player in Roche's Lucentis, Eylea has done remarkably well, producing U.S. sales of more than $400 million in the fourth quarter of last year. This year, Regeneron is guiding for U.S. sales of $1.7 billion to $1.8 billion.

The rest of Regeneron's value can mostly be attributed to the pipeline it's building through a partnership with Sanofi (NASDAQ:SNY). Fool contributor Brian Orelli and health-care bureau chief Max Macaluso discuss Regeneron and Sanofi's drugs that are on the market and pipeline, including alirocumab, their PCSK9 inhibitor that will compete against Amgen's (NASDAQ:AMGN) evolocumab if both drugs are approved.