What happened

Shares of the Irish biopharma Amarin Corp. (AMRN -0.11%) rose by as much as 11.9% in early action Wednesday morning. While the company didn't release any news that would spark this double-digit rally today, Amarin's shares have been gaining favor among a number of Wall Street analysts and bargain hunters ever since the company's cliff dive at the end of March.

In fact, Amarin's stock is up by almost 40% since hitting a multiyear low at the end of March. The biopharma's shares have cooled off a bit since their red-hot start to Wednesday's trading session, but they're still up by a healthy 10.3% on higher-than-normal volume, as of 11:41 a.m. EDT. 

A hand using a red string to illustrate a positive growth trend.

Image Source: Getty Images.

So what

As a refresher, Amarin's shares lost over 70% of their value on March 31 in response to an adverse patent ruling for Vascepa in the United States. This patent ruling is a big deal because it potentially paves the way for generic competitors to enter the U.S. market.

Even under a worst-case scenario, though, a generic competitor probably won't enter the U.S. market for at least a full year from now. Amarin, after all, plans on appealing this unfavorable legal decision, a process that's expected to take no less than 12 months.  

Now what

The good news is that Amarin should hear back about Vascepa's pending European regulatory filing by the end of the year. Some analysts think an approval in the EU could be worth $1.5 billion to $2 billion in annual sales, which is a sizable commercial opportunity for a company with a market cap of about $2 billion right now.

All in all, this beaten-down biopharma stock arguably still has a lot to offer growth and value investors alike, even with this seminal patent issue hanging in the balance.