(AMRN) Receives FDA Notification That Action on ANCHOR

FDA Reviewing Amarin Request to Reinstate ANCHOR SPA

BEDMINSTER, N.J. and DUBLIN, Ireland, Dec. 20, 2013 — Amarin Corporation plc (Nasdaq:AMRN), a biopharmaceutical company focused on the commercialization and development of therapeutics to improve cardiovascular health, announced today that the U.S. Food and Drug Administration (FDA) notified the company last night that the FDA does not expect to take action on Amarin’s supplemental new drug application (sNDA) for the proposed ANCHOR indication labeling expansion for Vascepa^® (icosapent ethyl) capsules on the December 20, 2013 Prescription Drug User Fee Act (PDUFA) goal date because Amarin’s request to re-instate the ANCHOR Special Protocol Assessment (SPA) agreement remains under consideration with the FDA. No new PDUFA date was established.

The FDA also communicated to Amarin that it now views Amarin’s appeal of the ANCHOR SPA agreement rescission and the ANCHOR sNDA as separate administrative decisions worthy of separate consideration. FDA plans to complete its review of Amarin’s request to re-instate the ANCHOR SPA agreement and plans to convey its decision to Amarin no later than January 15, 2014. The FDA provided no additional information on when it expects to complete its review of the ANCHOR sNDA.

Vascepa is currently FDA approved for use as an adjunct to diet to reduce triglyceride levels in adult patients with severe (≥500 mg/dL) hypertriglyceridemia. The ANCHOR sNDA seeks approval of Vascepa for use as an adjunct to diet and exercise for adult patients on statin therapy with mixed dyslipidemia (one or more lipid disorder) and triglyceride levels between 200 and 499 mg/dL.

Amarin plans to continue to work with the FDA to pursue reinstatement of the ANCHOR SPA agreement and approval of the ANCHOR sNDA. There can be no assurance that Amarin will be successful in this effort.

About Vascepa^® (icosapent ethyl) capsules

Vascepa^® (icosapent ethyl) capsules, known in scientific literature as AMR101, is a highly pure-EPA omega-3 prescription product in a 1 gram capsule.

Indications and Usage

• Vascepa (icosapent ethyl) is indicated as an adjunct to diet to reduce triglyceride (TG) levels in adult patients with severe (≥500 mg/dL) hypertriglyceridemia.
• The effect of Vascepa on the risk for pancreatitis and cardiovascular mortality and morbidity in patients with severe hypertriglyceridemia has not been determined.

Important Safety Information for Vascepa

• Vascepa is contraindicated in patients with known hypersensitivity (e.g., anaphylactic reaction) to Vascepa or any of its components and should be used with caution in patients with known hypersensitivity to fish and/or shellfish.
• The most common reported adverse reaction (incidence > 2% and greater than placebo) was arthralgia (2.3% for Vascepa, 1.0% for placebo).

FULL VASCEPA PRESCRIBING INFORMATION CAN BE FOUND AT WWW.VASCEPA.COM.

Vascepa is under various stages of development for potential use in indications that have not been approved by the FDA. Nothing in this press release should be construed as promoting the use of Vascepa in any indication that has not been approved by the FDA.

About Amarin

Amarin Corporation plc is a biopharmaceutical company focused on the commercialization and development of therapeutics to improve cardiovascular health. Amarin’s product development program leverages its extensive experience in lipid science and the potential therapeutic benefits of polyunsaturated fatty acids. Vascepa^® (icosapent ethyl), Amarin’s first FDA approved product, is a patented, ultra pure omega-3 fatty acid product comprising not less than 96% EPA. For more information about Vascepa visit www.vascepa.com. For more information about Amarin visit www.amarincorp.com.

Forward-looking statement

This press release contains forward-looking statements, including statements about anticipated FDA review of the ANCHOR SPA rescission decision and ANCHOR sNDA and the timing of such reviews, and Amarin’s plans to continue to pursue reinstatement of the ANCHOR SPA and approval of the ANCHOR sNDA. These forward-looking statements are not promises or guarantees and involve substantial risks and uncertainties. Among the factors that could cause actual results to differ materially from those described or projected herein include the following: uncertainties associated generally with research and development, clinical trials and related regulatory approvals; the risk that SPA agreements with the FDA are not a guarantee that FDA will approve a product candidate; the risk associated with the FDA’s rescinding of the ANCHOR SPA agreement; the risk that FDA will follow the recommendation of the advisory committee against ANCHOR sNDA approval; the risk that the FDA may not complete its review of the ANCHOR SPA reinstatement or sNDA in the timing expected; and the risk that Amarin’s interpretation of the applicable legal standards and scientific information related to the SPA agreement rescission may not be determinative or adjudicated in Amarin’s favor or at all. A further list and description of these risks, uncertainties and other risks associated with an investment in Amarin can be found in Amarin’s filings with the U.S. Securities and Exchange Commission, including its most recent Quarterly Report on Form 10-Q. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. Amarin undertakes no obligation to update or revise the information contained in this press release, whether as a result of new information, future events or circumstances or otherwise.

Availability of other information about Amarin

Investors and others should note that we communicate with our investors and the public using our company website (www.amarincorp.com), our investor relations website (http://www.amarincorp.com/investor-splash.html), including but not limited to investor presentations and investor FAQs, Securities and Exchange Commission filings, press releases, public conference calls and webcasts. The information that we post on these channels and websites could be deemed to be material information. As a result, we encourage investors, the media, and others interested in Amarin to review the information that we post on these channels, including our investor relations website, on a regular basis. This list of channels may be updated from time to time on our investor relations website and may include social media channels. The contents of our website or these channels, or any other website that may be accessed from our website or these channels, shall not be deemed incorporated by reference in any filing under the Securities Act of 1933.

CONTACT: Joseph Bruno
         Investor Relations and Corporate Communications
         Amarin Corporation
         In U.S.: +1 (908) 719-1315
         investor.relations@amarincorp.com