Shares of Regeneron (NASDAQ:REGN), which were trading below $500 ahead of the biggest healthcare investors conference of the year, have been on the rise following the company's recent presentation. Wall Street analysts have upgraded the stock, and Benchmark analyst Aydin Huseynov raised his price target to $590 per share.

On Tuesday, the U.S. government agreed to buy another 1.25 million doses of Regeneron's antiviral treatment for COVID-19. But the deal, worth up to $2.6 billion, isn't the biggest reason Wall Street is bullish on Regeneron.

Scientists investigating something important.

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Analysts have been impressed by rapidly rising sales of recently launched drugs that appear capable of offsetting potential pressure for its blockbuster vision-loss treatment Eylea. Regeneron leaned on Eylea for about 74% of total revenue in 2019, but a key patent expiration in 2023 could expose the Eylea brand to biosimilar competition.  

Dupixent, a treatment for eczema that Regeneron developed in partnership with Sanofi (NASDAQ:SNY), now appears capable of offsetting potential Eylea losses. Sales of Dupixent grew 69% year over year to an annualized $4.4 billion in the third quarter. By the end of 2022, Regeneron expects to submit six applications for different indications that could expand Dupixent's addressable patient population and annual sales to more than $12 billion at its peak.

Dupixent isn't the only new drug pushing Regeneron's big needle forward. Libtayo, a cancer immunotherapy that Sanofi helps Regeneron market outside of the U.S., is under priority review by the Food and Drug Administration for the first-line treatment of the most commonly diagnosed form of lung cancer.

By the end of 2022, Regeneron also expects to submit applications for five completely new drugs. Passing $590 a share might not happen overnight, but it isn't going to be a problem for this biotech stock.

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