Big biotech stocks like Alexion Pharmaceuticals (ALXN) and Regeneron (REGN -1.75%) have soared through the market's recent rally with flying colors. These two stocks alone each have captured more than 90% growth over that time, as climbing sales of top drugs have impressed investors and Wall Street. Regeneron and Alexion look like winners heading forward, but which company -- and stock -- is on the best track for long-term growth?

Alexion's grown famous for Soliris, its orphan drug that's the most expensive in the world. Soliris isn't just a pricey therapy, however; it's also an unstoppable blockbuster, reaping more than $1.5 billion in sales last year at growth of 37% year over year. Analysts think Alexion's top drug has plenty more room to run, but big biotech peer Regeneron has a star drug of its own. Regeneron'seye therapy Eylea has taken the biotech world by storm over the past year, reaping more than $1.8 billion in global sales last year and on pace to pick up more revenue this year.

Both companies have developing programs in their pipelines as well, but which stock is more worthy of your investment? Find out in the video below, as Motley Fool contributor Dan Carroll takes you through the ins and outs of these two soaring stocks and their standout drugs -- and which one's set up for the best growth in the future.

)