What happened

Shares of Amarin (NASDAQ:AMRN) rose more than 16% after the company issued a mid-2019 business update. Management increased full-year 2019 revenue guidance from a previous target of $350 million to a new midpoint of $400 million. The boost comes on the heels of soaring demand for Vascepa, which is currently approved to treat very high triglycerides. Of course, the drug's most promising application -- being prescribed to reduce cardiovascular risks -- has yet to even be approved by the U.S. Food and Drug Administration.

Anticipation of that decision, expected in late September, hasn't stopped momentum. First-half 2019 revenue is expected to have been in the neighborhood of $172 million. Although results haven't been finalized, investors aren't letting informality get in the way of their optimism. As of 3:32 p.m. EDT, the stock had settled to a 15.7% gain.

A businessman striking a pose and pointing up to the right.

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So what

Shares of Amarin have soared 618% in the last year after the company reported impressive results from the massive REDUCE-IT trial. The study showed that Vascepa, a concentrated formulation of an omega-3 fatty acid, delivered a 25% relative risk reduction compared to placebo in the first occurrence of a major adverse cardiovascular event. In other words, it could significantly improve the health of individuals with heightened risk factors, namely elevated levels of bad cholesterol (LDL-C).

That has analysts eyeing peak annual sales potential measured in billions of dollars, with some optimistic projections approaching $10 billion per year. The market is certainly there for a simple oral drug such as Vascepa. Amarin isn't wasting time ahead of the FDA's decision, expected on Sept. 28, and announced plans to double its U.S. sales force to 800 representatives by October.

Now what

Today's news is just the latest piece of information suggesting that Amarin has a promising future. If Vascepa achieves full-year 2019 revenue guidance, then it will achieve year-over-year sales growth of 75%. And, of course, a midpoint of $400 million might just be a fraction of the drug's eventual peak sales. Now all investors can do is wait for the FDA's decision to be handed down in September.

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