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 (NYSE: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.

Brian Orelli, Max Macaluso, Ph.D., and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.