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MYSTIC, Conn. ( TheStreet) -- Amarin's ( AMRN) medicinal-grade fish oil drug AMR101 significantly lowered triglyceride levels without raising "bad" LDL cholesterol, according to results of late-stage study reported Monday.

Amarin said AMR101 met all the efficacy and safety endpoints in the phase III study and as a result, the company will seek U.S. approval next year instead of in 2012 as had been in expected.

Amarin shares were up about 62% to $5.75 in early Monday's trading.

AMR101 is an ultra-purified form of the omega-3 fatty acid known as Ethyl EPA.

The phase III study known as "MARINE" enrolled patients with very high triglyceride baseline levels above 500 mg/dl and treated them with two doses of AMR101 or a placebo for 12 weeks. Twenty-five percent of the patients were also on background cholesterol-lowering statin therapy.

Patients treated with the 4 grams/day (high dose) of AMR101 showed a median triglyceride reduction of 33% compared to placebo. Patients treated with the 2 grams/day (low dose) of AMR101 had a 20% reduction in triglycerides compared to placebo. The reductions in both groups were statistically significant.

Patients entered the AMR101 study with median baseline triglyceride levels ranging from approximately 650 mg/dl to 700 mg/dl. Doctors generally consider normal triglyceride levels to be around 150 mg/dl or lower.

GlaxoSmithKline ( GSK) markets a prescription fish oil drug known as Lovaza that demonstrated a 45% reduction in triglyceride levels, according to the drug's label. While this appears superior to AMR101, the baseline triglyceride level of patients in the pivotal Lovaza study was around 800 mg/dl -- higher than it was in Amarin's MARINE study.

Amarin says AMR101 was even more effective for a subset of patients in the MARINE study with baseline triglycerides in the 900-1,000 mg/dl range, or comparable to patients described in the Lovaza label.

For these patients, treatment with the high dose of AMR101 led to a 45% reduction in triglycerides.

Treatment with AMR101 also did not result in a statistically significant increase in levels of LDL or "bad" cholesterol compared to placebo Patients treated with the high and low doses of AMR101 reported a 2.3% drop and a 5.2% increase in LDL cholesterol, respectively, verus placebo.

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