Amarin (Nasdaq: AMRN) jumped 65% yesterday after releasing phase 3 data for its fish oil drug, AMR101. That sounds about right. So far, AMR101 looks like a wonder drug, and its potential is huge.

In a phase 3 trial dubbed Marine, the highly purified and concentrated fish oil lowered triglyceride levels by as much as 33%, without raising "bad" LDL cholesterol levels.

GlaxoSmithKline (NYSE: GSK) currently has a prescription-grade fish oil drug, Lovaza, on the market that has brought in $590 million through the first three quarters of 2010. Lovaza, however, raises bad cholesterol levels, which limits its use to just patients with very high triglyceride levels.

Amarin is running another phase 3 trial called Anchor -- can you see the aquatic theme? -- with patients who have intermediately high triglyceride levels. Passing that trial without any hiccups could put AMR101 in the multibillion-dollar drug category. The moderately high triglyceride market is huge. It's not like Americans eat very well. Just look at sales of Pfizer's (NYSE: PFE) Lipitor, AstraZeneca's (NYSE: AZN) Crestor, and Merck's (NYSE: MRK) Vytorin.

Assuming the drug passes the Anchor trial, the biggest issue I see with AMR101 is the patent protection. Amarin says this trial could extend patent claims out to 2030, and the company lists a disease-specific patent that expires in 2021 on its website. Method-of-use patents are a lot easier to break than composition of matter patents. The biggest long-term winner from AMR101 may turn out to be generic-drug makers.

Investors can worry about that at a later date, though. For now, enjoy the run upward, and look for a little more if the Anchor trial turns up positive next year.

Interested in keeping track of Amarin as it moves AMR101 toward the market? Click here to add it to My Watchlist, which will help you keep track of all our Foolish analysis on Amarin.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool has a disclosure policy.