Mystic - Amarin Corp. plc received rave reviews Tuesday following the announcement that a late-stage trial of its cardiovascular medication AMR101 had met with success.

The trial, involving people with high levels of triglycerides, showed that patients significantly reduced this well-studied risk factor in cardiovascular disease when they took Amarin's experimental omega-3 fish oil. What's more, the reduction of triglycerides did not come with an increase of LDL "bad" cholesterol that is associated with similar medicines, such as GlaxoSmithKline's Lovaza, Amarin officials said.

"So far, AMR101 looks like a wonder drug, and its potential is huge," said The Motley Fool website, summing up reaction in the investment community.

Mystic-based Amarin's stock price took a breather Tuesday after a spectacular 65 percent runup the day before, but still is near its year-to-date high of $5.85 recorded at the end of trading Monday. A year ago, the stock could be bought for under $1 a share.

And Amarin officials, in a conference call, indicated that more good news may be on the horizon. That's because the company is due to complete by the middle of next year another late-stage clinical trial of AMR101, called Anchor, involving people with moderate triglyceride levels - a huge market that has been untapped because other prescription-grade fish oils have the side effect of causing dangerous increases of LDL cholesterol.

"Passing that trial without any hiccups could put AMR101 in the multibillion-dollar drug category," Brian Orelli of The Motley Fool said on its website, www.thefool.com.

Amarin said about 3.8 million Americans have very high levels of triglycerides, while 40 million would be considered to have elevated levels.

Amarin officials said they would be submitting a new drug application for AMR101 to the U.S. Food and Drug Administration sometime next year.

Joseph J. Zakrzewski, executive chairman and chief executive of Amarin, said in a conference call that the company is leaning toward separate applications related to the two different indications for AMR101.

Zakrzewski called the so-called Marine study, released Monday, "an extraordinary result," and said Amarin officials feel a sense of elation at the idea that their hard work, completed over the Thanksgiving holiday, had led to a "revolutionary therapy for treating triglycerides."

AMR101's lead investigator, Dr. Harold Bays, medical director of the Louisville Metabolic and Atherosclerosis Research Center, said he was surprised at the pill's lack of effect on LDL cholesterol.

He said a subgroup of patients being treated with cholesterol-lowering statins also showed surprisingly significant results, and AMR101 also had favorable effects in other markers of cardiovascular health as well as being safe to take.

Bays said in a statement that AMR101 "not only represents a new chemical entity, but a potential novel therapy" that differs from all current triglyceride-lowering agents.

Zakrzewski said some of the Marine study's unexpected results, including AMR101's effect on inflammation and LDL cholesterol, could point to other potential uses for the drug. He said the company has filed additional patent requests based on data from the AMR101 study.

"What we think we have right now goes well beyond cardiovascular," he said.

Brian Orelli of TheMotleyFool said his biggest concern with AMR101 is patent protection, which Amarin is hoping to extend to 2030.

"The biggest long-term winner from AMR101 may turn out to be generic-drug makers," he said. "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."

l.howard@theday.com