Conference Coverage

High-dose fish oil: ‘Intriguing’ results in COVID-19



A high dose of the purified form of eicosapentaenoic acid, icosapent ethyl (Vascepa, Amarin), failed to significantly reduce hospitalizations or death in patients infected with COVID-19 in the PREPARE-IT 2 study.

The study did, however, show a favorable trend, with a 16% reduction in the primary endpoint of death or an indication for hospitalization. All secondary endpoints were also numerically reduced, but none reached statistical significance.

The product was also well tolerated over the 28 days of the study period, even though a new high-loading dose was used, with no increase in atrial fibrillation or bleeding or other adverse events versus placebo, although there was a slightly higher rate of discontinuation.

The trial was presented at the American Heart Association scientific sessions on Nov. 15 by Rafael Díaz, MD, director of Estudios Clínicos Latinoamérica in Rosario, Argentina.

“Larger, randomized trials powered for a relative risk reduction of around 15% with icosapent ethyl are needed to establish whether or not this product may have a role in the management of COVID-positive outpatients,” Dr. Diaz concluded.

‘Intriguing signals’

Commenting on the study, Manesh Patel, MD, chief of the division of cardiology and codirector of the Heart Center at Duke University, Durham, N.C., and chair of the Scientific Sessions scientific program, said that: “Certainly there are some intriguing signals.”

“I think the trend is valuable, but do we need a larger trial to confirm a benefit? I will leave that to the clinical community to decide,” Dr. Patel added. “But it is hard to power a trial to get that answer, and the world of COVID has changed since this trial started with vaccines now available and new therapeutics coming. So, there’s going to be a competing landscape.”

Discussing the trial at an AHA news briefing, Erin Michos, MD, associate professor of medicine within the division of cardiology at Johns Hopkins University, Baltimore, said: “Results showed that everything trended in the right direction, but did not reach statistical significance largely because there were fewer events than anticipated. COVID hospitalizations are going down because of the broad adoption of vaccines, which meant that this study didn’t quite meet its endpoint.”

But, she added: “Reassuringly, even with the higher loading dose, there was no increased risk of [atrial fibrillation] when used for just 28 days, and no increased risk in bleeding, so there was very good safety.”

“We need a larger trial to really definitely show whether icosapent ethyl can or cannot help COVID-positive outpatients, but I think a better prevention strategy would be the broad adoption of vaccinations globally,” Dr. Michos concluded.

‘A pretty big ask’

Donald Lloyd-Jones, MD, AHA president and designated discussant at the late-breaking science session, congratulated the investigators on conducting “a very nice pragmatic trial in the midst of the COVID pandemic.”

Dr. Lloyd-Jones concluded that the broad range of potentially beneficial actions of icosapent ethyl – including antitriglyceride, anti-inflammatory, antioxidant, and antithrombotic effects – leads to the possibility of it helping in COVID, but he added that “this is a pretty big ask for a fish oil supplement given short term.”

Presenting the study, Dr. Diaz noted that there are limited options for the outpatient treatment of patients with COVID-19 infection, and it is believed that inflammation plays a major role in worsening the severity of the infection.

He pointed out that previous data support a potential role of omega-3 fatty acids in reducing inflammation and infection, and that icosapent ethyl has shown a reduction in major cardiovascular events in the REDUCE-IT trial, with the mechanism thought to involve anti-inflammatory effects.

In the first trial to investigate the role of icosapent ethyl in COVID-19, PREPARE-IT, the product did not prevent uninfected individuals at risk from COVID from becoming infected with the virus, but there was no increase in side effects versus placebo with use over a 60-day period.

A small study last year in 100 COVID-positive patients showed icosapent ethyl reduced C-reactive protein, an inflammatory marker, and also improved symptoms.

PREPARE-IT 2, a pragmatic web-based trial, was conducted to investigate whether icosapent ethyl in nonhospitalized patients with a positive diagnosis of COVID-19 could reduce hospitalization rates and complications.

The trial enrolled 2,052 patients (mean age, 50 years), of whom 1,010 were allocated to the active group and 1,042 to the placebo group. Inclusion criteria included individuals aged 40 years or older with a confirmed COVID-19 diagnosis and no more than 7 days from the onset of symptoms and without a clear indication for hospitalization.

Patients who were allocated to the active arm received icosapent ethyl at a dose of 8 g (four capsules every 12 hours, morning and evening) for the first 3 days, followed by 4 g (two capsules every 12 hours) thereafter (days 4-28).

The primary outcome, COVID-19–related hospitalization (indication for hospitalization or hospitalization) or death at 28 days, occurred in 11.16% of the active group and 13.69% of the placebo group, giving a hazard ratio of 0.84 (95% confidence interval, 0.65-1.08; P = .166)

Secondary outcomes showed similar positive trends, but none were significant. These included: death or still hospitalized at 28 days (HR, 0.74), major events (MI, stroke, death; HR, 0.38), and total mortality (HR, 0.52).

In terms of safety, there was no significant difference in total adverse events between the two groups (16.5% in the active group vs. 14.8% in the placebo group). The most common adverse effects were constipation (2.7%), diarrhea (7.2%), and nausea (4%), but these were not significantly different from placebo. There were, however, more discontinuations in the active group (7% vs. 4%).

Dr. Diaz pointed out that the PREPARE-IT 2 trial was started in May 2020, when there wasn’t much known about the COVID-19 condition, and there were no vaccines or treatments, so hospitalization rates were high.

“We were hoping to see a 25%-30% reduction in hospitalizations with icosapent ethyl, and the trial was powered for that sort of reduction, but today we know we can expect a more modest reduction of about 15%,” Dr. Diaz concluded. “But to show that, we need a much larger trial with 8,000 or 9,000 patients, and that will be much more difficult to conduct.”

The PREPARE-IT 2 study was funded by Amarin. Dr. Diaz has received grants from Dalcor, Amarin, PHRI, and Lepetit.

A version of this article first appeared on

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