Image source: Regeneron Pharmaceuticals.

What: Ahead of second-quarter financial results and a key decision by the Food and Drug Administration, shares in Regeneron Pharmaceuticals (NASDAQ:REGN) soared 18.6% in July, according to S&P Global Market Intelligence.

So what: The company's Eylea is already one of the top-selling drugs in the world and results from key trials in the past year suggest that Regeneron may soon have two more drugs with blockbuster potential on the market.

Eylea is used to treat age-related macular degeneration and diabetic macular edema and recently released second-quarter sales show sales are clocking in at an annualized $4.8 billion pace. Eylea's U.S. sales increased 27% in the quarter versus a year ago and internationally, where Bayer is responsible for commercialization, Eylea revenue grew to $486 million from $338 million in the second quarter of 2015. Regeneron's share of those overseas sales improved to $167 million from $107 million a year ago.

The company also made some sales headway for its cholesterol-lowering drug Praluent, which it markets with partner Sanofi SA (NASDAQ:SNY). Praluent won FDA approval last summer and sales in the second quarter totaled $24 million.

Image source: Regeneron Pharmaceuticals.

Investor optimism, however, is likely more due to potential sales growth in the coming year from sarilumab and dupilumab, two monoclonal antibody drugs that target rheumatoid arthritis and eczema, respectively.

In trials, sarilumab bested the world's best-selling drug, Humira, and dupilumab became the first systematic therapy to post positive phase 3 results in moderate to severe eczema patients. Regeneron and collaborator Sanofi have filed for FDA approval of both drugs and an FDA decision on sarilumab is slated for Oct. 30. The dupilumab application was recently filed with the FDA and a decision date has yet to be set. Typically, a FDA go/no-go verdict is issued 10 months after the regulator officially accepts the application, suggesting a potential approval in the first half of 2017.

Now what: Investors had billion-dollar blockbuster hopes for Praluent, but those have so far been dashed, leading to a sharp sell-off in Regeneron shares over the past year. That sell-off, however, may be creating an opportunity for long-term investors eager to own what could be one of the biggest biotech companies in the coming years. Regeneron is already handsomely profitable, and with its pipeline yielding some potentially big wins, this is one company not to ignore.

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