What: Shares of Amarin (NASDAQ:AMRN), a small-cap biopharmaceutical company focused on developing drugs designed to treat cardiovascular diseases, lifted off in May and rose by 20% based on data from S&P Capital IQ, after announcing a positive judgment in a legal case against the U.S. Food and Drug Administration.

So what: According to the press release from Amarin this past Thursday, federal district court judge Randolph D. Moss of the District of Columbia granted the company's motion for summary judgment against the FDA concerning Vascepa, Amarin's high-triglyceride treatment. This lawsuit sought an order requiring the FDA to recognize a five-year, new chemical entity, marketing exclusivity window for Vascepa.

Source: Amarin.

The bigger point here is that the court's ruling would mean the FDA couldn't accept abbreviated new drug applications, or ANDAs, for generic versions of Vascepa until July 2016 at the earliest (since the five-year NCE mark should carry Vascepa through July 25, 2017). It's possible Amarin may be able to move to dismiss prior Vascepa patent litigation, too.

Now what: On one hand it's great to see Amarin secure a victory in court that validates Vascepa as an NCE and protects it from generic rivals for another couple of years. It's an especially important victory, because Amarin is currently undertaking a long-term cardiovascular outcomes trial involving Vascepa, known as REDUCE-IT, which isn't even expected to end until 2018. The longer Amarin can keep its foes at bay, the better chance it has of possibly delivering positive results in REDUCE-IT and expanding Vascepa's label indications into a much larger percentage of the high-triglyceride population.

On the other hand, Amarin is burning through its cash on hand, and it could struggle to make ends meet long before it has any chance of expanding Vascepa's label indications. Dilutive common stock offerings are a possibility. Additionally, there are no guarantees that REDUCE-IT will hit its primary endpoint. In other words, there's certainly the potential for a lot of upside if Vascepa is expanded, but the sheer amount of time that investors will need to wait to get this data, and the potential that it may not meet its primary endpoint, are all reasons to keep your distance from this stock.