Amarin Reports Second Quarter 2013 Financial Results and Provides Update on Operations - Conference Call Set for 4:30 p.m. EST Today - BEDMINSTER, N.J., and

Amarin Reports Second Quarter 2013 Financial Results

and Provides Update on Operations

- Conference Call Set for 4:30 p.m. EST Today -

BEDMINSTER, N.J., and DUBLIN, Ireland,

August 8, 2013 Amarin Corporation plc (Nasdaq: AMRN), a late-stage biopharmaceutical company focused on the commercialization and development of therapeutics to improve cardiovascular health, today announced financial results

for Q2, the quarter ended June 30, 2013, and provided an update on company operations.

Key Amarin accomplishments since March 31,

Since the end of Q1, revenues, prescription levels, prescribing physicians and lives covered under

Tier 2 have all more than doubled, said Joseph Zakrzewski, Chairman and Chief Executive Officer of Amarin. We have witnessed the awareness, knowledge level and utilization of Vascepa strengthen and expand across our group of

targeted physicians. The efficacy and safety profile of Vascepa for its approved indication continue to be well received and we plan to continue to drive increased physician awareness and managed care coverage to further grow revenues. In addition,

we believe we are well positioned for approval by the U.S. Food and Drug Administration, or FDA, in December to expand Vascepa labeling from our approved MARINE indication to the significantly larger population represented by our proposed ANCHOR

Commercialization update

Amarin s direct sales force, consisting of

approximately 275 sales professionals, launched Vascepa on January 28, 2013, for use as an adjunct to diet to reduce triglyceride levels in adult patients with severe (>500 mg/dL) hypertriglyceridemia, the initial indication for

Vascepa, or MARINE indication. Amarin reports that, since launch, access to clinicians has been good, and that it has yet to hear any significant negative reaction to the efficacy or safety profile of Vascepa. Amarin s sales professionals are

currently targeting the limited group of clinicians who are the highest prescribers of other lipid therapies and seeking, in particular, to increase awareness and knowledge of Vascepa among this group. Amarin believes that Vascepa is well

differentiated in this market based on its safety profile, which is comparable to placebo, and on its spectrum of demonstrated lipid benefit at 4 g/day, including statistically significant reductions in TGs, Apo B, VLDL-C, and non-HDL-C, with no

increase in LDL-C, also known as bad cholesterol.

Vascepa additional indication progress

In parallel with marketing Vascepa for the MARINE indication, Amarin is pursuing FDA approval of Vascepa for the ANCHOR indication, a second indication in

a significantly larger adult patient population, those with mixed dyslipidemia and TG levels between 200 and 499 mg/dL.

announced, in a clinical trial of the use of Vascepa in the ANCHOR indication, Vascepa demonstrated statistically significant reductions in a broad spectrum of lipid and inflammatory markers, on top of optimized statin therapy, including significant

reduction in LDL-C compared to placebo. The FDA has accepted for review Amarin s Supplemental New Drug Application, or sNDA, for the ANCHOR indication and has assigned a PDUFA action date of December 20, 2013 for this sNDA. In addition,

the FDA has scheduled a meeting of the Endocrinologic and Metabolic Drugs Advisory Committee (EMDAC) to review the ANCHOR application to be held on October 16, 2013. The safety results from the ANCHOR trial are included in the current label for

The ANCHOR study, which evaluated the efficacy of Vascepa in lowering triglycerides on top of optimized statin therapy for adult

mixed dyslipidemia patients with high triglyceride levels (>200 to <500 mg/dL), was conducted under a special protocol assessment, or SPA, agreement with the FDA. An SPA is generally considered to be binding upon the FDA except in

limited circumstances, such as if the FDA identifies a substantial scientific issue essential to its determining the efficacy or safety of a drug. Amarin has not been informed by FDA of any such essential issue. Amarin believes that it achieved all

of the requirements of the SPA agreement. In particular, in the ANCHOR trial, with Vascepa 4 grams per day, all primary and secondary efficacy endpoints were achieved, including a reduction in LDL-C levels compared to placebo. Amarin is optimistic

that the FDA will approve Vascepa for this indication and looks forward to the advisory committee meeting as an opportunity to highlight the positive safety and efficacy profile of Vascepa. If approved, Vascepa will be the first drug in its class to

be approved for this multi-billion dollar market opportunity. Approximately one in five adults in the United States have triglyceride levels of >200 mg/dL.

Vascepa exclusivity update

Amarin continues to make significant progress in its

effort to expand patent protection for Vascepa and now has 27 patents issued or allowed in the United States with over 30 additional U.S. patent applications being prosecuted. This patent portfolio includes claims covering Vascepa s

pharmaceutical composition and methods of use for the MARINE indication, ANCHOR indication and other potential uses of Vascepa. Amarin is also pursuing patent applications related to Vascepa in multiple jurisdictions outside the United

States. In May 2013, the European Patent Office granted a patent covering the use of Vascepa based on the results from the MARINE trial. All but two of the granted patents in the United States have expiry dates extending into 2030 and the majority

of U.S. patent applications, if and when allowed, are anticipated to have expiry dates in or beyond 2030. Patent protection for Vascepa is augmented by protection provided by trade secrets, existing manufacturing barriers to entry and anticipated

three- or five-year regulatory exclusivity.

REDUCE-IT and other Vascepa-related clinical development

During Q2, the FDA accepted Amarin s sNDA for the ANCHOR indication, a precondition for which was that the REDUCE-IT cardiovascular outcomes study be

substantially underway. Consistent with Amarin s Special Protocol Assessment (SPA) agreement, and based on the company s discussions with the FDA, the company does not believe the final results of the REDUCE-IT study will be required for

FDA approval of Vascepa for the ANCHOR indication, although there can be no assurance that this will

be the case. During Q2, the mean and median baseline triglyceride levels for patients participating to date in the REDUCE-IT cardiovascular outcomes study has been confirmed to be >200 mg/dL.

As intended, these are higher baseline TG levels than levels studied in other recent outcomes trials of other lipid modifying therapies. Results of the REDUCE-IT study will not be available until a specified number of cardiovascular events have been

observed, the timing of which is not expected in the near-term.

Amarin reported cash and cash equivalents on-hand of $149.4 million at June 30, 2013. On July 12, 2013, Amarin completed a public offering

resulting in additional net proceeds to Amarin of approximately $121.1 million, after deducting the company s portion of estimated offering expenses, resulting in aggregate pro forma cash and cash equivalents of $270.5 million as of

Vascepa s commercial launch commenced on January 28, 2013 in the United States. The quarter ended June 30,

2013 is the first full quarter of Vascepa sales. Amarin reported net product revenues for the quarter ended June 30, 2013 of $5.5 million as compared to revenue of $2.3 million for the quarter ended March 31, 2013 and no revenues in the

corresponding periods of 2012. In accordance with U.S. Generally Accepted Accounting Principles (US GAAP), and consistent with Q1 reporting, until the company has more operating history with the commercialization of Vascepa, it is recognizing

revenue based not on its sales to wholesalers but based on the resale of Vascepa for the purpose of filling prescriptions. For the six months ended June 30, 2013, the net value of Vascepa sold to wholesalers was $9.6 million, and, as a result,

in addition to $7.8 million in recognized revenue, Amarin recorded deferred revenue of $1.8 million at June 30, 2013. Cash collections from the sale of Vascepa in the quarter ended June 30, 2013 were approximately $6.6 million for a total

of $9.4 million collected from wholesalers since the launch of Vascepa.

Consistent with industry practice, the net price of Vascepa for the

six months ended June 30, 2013 reflects the deduction of one-time discounts paid to wholesalers to stock Vascepa in advance of Vascepa s launch in January 2013, as well as the costs of a co-payment rebate card program and customary payor

rebates and allowances. The net price also includes adjustments for other customary amounts.

Cost of goods sold during the quarter ended

June 30, 2013 was $2.8 million as compared to $1.3 million for the quarter ended March 31, 2013. Gross margin as a percentage of net revenues improved from 45% to 48% in the second quarter as compared to the first quarter of 2013. The

majority of Vascepa capsules sold during the six months ended June 30, 2013 included API sourced from a single API supplier. Amarin s purchases of API from this supplier in 2012 and early 2013 are at higher cost per kilogram than expected

future purchases from this supplier. The unusually high cost of goods, as a percentage of revenue, is attributable to a number of things including the geographic location of our suppliers, exchange rate exposures and lower volume and less favorable

economic terms than those with other API suppliers. Amarin expects steady state gross margin as a percentage of product revenues to approach the high seventies to low eighties as it increases purchase volumes and sources lower cost API. In April

2013, sNDAs were approved for two comparatively lower cost API suppliers, BASF and Chemport Inc. While current inventory is comprised primarily of inventory from the initial supplier, unless the company secures substantial price concessions from the

initial supplier, it anticipates shifting a substantial portion of future API purchases to these lower cost suppliers.

Amarin reported a net loss of $39.8 million in the second quarter of 2013, or basic and diluted loss per share of $0.26. This net loss included $5.1 million in non-cash, share-based

compensation expense, $1.0 million in non-cash, warrant compensation income, and a $18.8 million gain on the change in the fair value of derivatives. In the second quarter of 2012, GAAP net loss

was $53.9 million, or basic and diluted loss per share of $0.38, and included $4.8 million in non-cash share-based compensation expense, $1.9 million in non-cash warrant compensation expense, and a $18.9 million loss on the change in the fair value

For the six months ended June 30, 2013, Amarin reported a net loss of $101.9 million, or basic and diluted loss per

share of $0.68. This net loss included $10.0 million in non-cash share-based compensation expense, $1.5 million in non-cash warrant compensation income, and a $22.5 million gain on the change in the fair value of derivatives. For the six months

ended June 30, 2012, GAAP net loss was $142.2 million, or basic and diluted loss per share of $1.03, and included $8.7 million in non-cash share-based compensation expense, $4.2 million in non-cash warrant compensation expense, and a $85.1

million loss on the change in the fair value of derivatives.

Excluding non-cash gains or losses for share-based compensation, warrant

compensation and change in value of derivatives, non-GAAP adjusted net loss was $54.5 million for the three months ended June 30, 2013, or non-GAAP adjusted basic and diluted loss per share of $0.36, as compared to non-GAAP adjusted net loss of

$28.3 million, or non-GAAP adjusted basic and diluted loss per share of $0.20 for the same period in 2012. Adjusted net loss was $115.9 million for the six months ended June 30, 2013, or non-GAAP adjusted basic and diluted loss per share of

$0.77, as compared to non-GAAP adjusted net loss of $44.1 million, or non-GAAP adjusted basic and diluted loss per share of $0.32 for the same period in 2012.

Amarin reported cash and cash equivalents decreased in aggregate by $110.8 million from December 31, 2012 as compared to June 30, 2013. Net cash outflows from operations were $52.8 million in

the second quarter of 2013 as compared to $59.6 million in the first quarter of 2013. As stated previously, Amarin anticipates its first quarter net cash outflows from operations to be its highest quarter of net cash outflows from operations during

2013. Amarin anticipates that it will experience continued reductions in quarterly net cash outflows from operations with future quarterly results below the results of the second quarter.

During the six months ended June 30, 2013, net cash outflows included approximately $48.2 million paid for sales and marketing related expenses in conjunction with the initial commercial launch of

Vascepa, approximately $16.7 million paid in support of the REDUCE-IT cardiovascular outcomes study and approximately $16.3 million for Vascepa API, purchased in conjunction with the buildup of commercial supply and for clinical trial material. Of

this $16.3 million in API purchases, $3.0 million was included as a component of research and development expense because it was received from suppliers prior to qualification by the FDA and the balance was capitalized as inventory.

Amarin s liabilities as of June 30, 2013, excluding the fair value of the non-cash warrant derivative liability, totaled approximately $273.0

million, which includes $141.5 million for the carrying value of exchangeable debt and $86.7 million for the carrying value of the hybrid debt financing that we entered into in December 2012.

As of June 30, 2013, Amarin had approximately 150.7 million ADSs outstanding as well as approximately 9.9 million, 11.2 million, and 0.9 million equivalent shares underlying

warrants, stock options, and restricted or deferred stock units, respectively, at average exercise prices of $1.44, $7.47 and $8.49, respectively. In addition, $150 million in exchangeable senior notes issued in January 2012 are exchangeable prior

to October 15, 2031 into an aggregate of 17.0 million ADSs (based on an initial exchange price of approximately $8.81 per ADS), subject to certain specified conditions. The notes accrue

interest at an annual rate of 3.5%, payable semiannually in arrears on January 15 and July 15, beginning July 15, 2012. The notes will mature on January 15, 2032, unless

earlier repurchased or redeemed by the company or exchanged by the holders. In conjunction with Amarin s previously announced financing in July 2013, Amarin issued 21.7 million additional ADSs.

Amarin s operational priorities

Operational priorities in the second half of 2013 are:

Conference call and webcast information

Amarin will host a conference call

at 4:30 p.m. EST (8:30 p.m. UTC/GMT) today, August 8, 2013. To participate in the call, please dial (877) 407-8033 within the United States or (201) 689-8033 from outside the United States. A replay of the call will be made

available for a period of two weeks following the conference call. To hear a replay of the call, dial (877) 660-6853 (inside the U.S.) or (201) 612-7415 (outside the U.S.). A replay of the call will also be available through Amarin s

website shortly after the call. For both dial-in numbers please use conference ID 416486. The conference call can also be heard live through the investor relations section of Amarin s website at www.amarincorp.com.

Use of non-GAAP adjusted financial information

Included in this press release and the conference call referenced above are non-GAAP adjusted financial information as defined by U.S. Securities and Exchange Commission Regulation G. The GAAP financial

measure most directly comparable to each non-GAAP adjusted financial measure used or discussed, and a reconciliation of the differences between each non-GAAP adjusted financial measure and the comparable GAAP financial measure, are included in this

press release after the condensed consolidated financial statements.

Non-GAAP adjusted net loss was derived by taking GAAP net loss and

adjusting it for non-cash gains or losses for share-based compensation, warrant compensation, and change in value of derivatives. Management believes that these non-GAAP adjusted measures provide investors with a better understanding of the

company s historical results from its core business operations. While management believes that these non-GAAP adjusted financial measures provide useful supplemental information to investors regarding the underlying performance of the