While Regeneron (REGN -0.09%) doesn't rank among top performers in the Nasdaq Composite, its year-to-date performance is still nothing short of impressive. Shares have risen around 180% and boosted the company's market capitalization to nearly $15 billion on the strength of Eylea, the company's flagship drug targeting age-related macular degeneration. The company reports earnings Wednesday, and as is the case for many high flying-stocks, hitting Wall Street's revenue estimates and offering strong guidance for the future will play a vital role in which direction the shares go.

In the following video, health care bureau chief Brenton Flynn outlines the competitive environment for Regeneron's Eylea, including one low-priced drug that could turn out to be its biggest competition.