Amarin Reports Second Quarter 2015 Financial Results and Provides Update on Operations - REDUCE-IT cardiovascular outcomes study progressing as planned - - Product revenue increased 40% over same period last year - - Con

Amarin Reports Second Quarter 2015 Financial Results

and Provides Update on Operations

- REDUCE-IT cardiovascular outcomes study progressing as planned -

- Product revenue increased 40% over same period last year -

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

BEDMINSTER, N.J., and DUBLIN, Ireland, August 6, 2015 Amarin Corporation plc (Nasdaq: AMRN), a biopharmaceutical company focused on the

commercialization and development of therapeutics to improve cardiovascular health, today announced financial results for the three and six months ended June 30, 2015, and provided an update on company operations.

Key Amarin achievements since March 31, 2015 include:

Based upon feedback from physicians and published case studies, Vascepa is increasingly recognized as an effective treatment therapy

for their patients, stated John F. Thero, President and Chief Executive Officer. We appear to be building positive momentum in multiple areas which we aim to build upon for sustainable commercial growth and we remain confident that our

cardiovascular outcomes study is positioned for success.

Commercialization update United States

Increases in product revenue were primarily attributable to increases both in new and recurring prescriptions of Vascepa. Revenue growth in the second quarter

of 2015 primarily resulted from increased shipment volumes of Vascepa to wholesalers in support of increased reorders and new orders of Vascepa. Data reflect that wholesalers on average stocked approximately six fewer days of sales of Vascepa at the

end of Q2 2015 than at the end of Q4 2014, which is understood to be a matter of timing and not an ongoing trend. The number of days of supply on hand at wholesalers tends to fluctuate based on the timing of weekly orders. The average net price of

Vascepa sold in Q2 2015 was lower than in Q2 2014 but very similar to the net price in Q1 2015. The average net price in Q2 2015 reflects additional rebates as a result of broader managed care coverage that was offset by the impact of a 6% price

increase effective June 1.

Normalized prescriptions (estimated) for the second quarter of 2015, based on data from Symphony Health Solutions and IMS

Health, totaled approximately 176,000 and 157,000, respectively. These prescription levels represent growth of approximately 14% and 15%, respectively, compared to the quarter ended March 31, 2015, and an increase of approximately 60% and 69%,

respectively, compared to the same quarter in 2014. This increase in prescriptions reflects the sales and marketing activities of both Amarin and our Vascepa co-promotion partner, Kowa Pharmaceuticals America, Inc.

Research on EPA continues to support potential benefits

Recent research findings continue to support the potential benefits of EPA, the active pharmaceutical ingredient in Vascepa. An in vitro study presented

in June at the American Diabetes Association Scientific Sessions in Boston, MA, showed that exposure to EPA inhibited glucose-induced oxidation of small dense LDL. Another in vitro study presented in June at the National Lipid Association

Scientific Sessions in Chicago, IL, showed that the inhibitory effect of EPA on the formation of cholesterol crystalline domains in model biological membranes subjected to high cholesterol levels (to simulate atherosclerotic-like conditions)

indicated a level of reduction with EPA that was not reproduced with other triglyceride-lowering agents tested.

A recent publication provides an in-depth

review of the literature-reported evidence supporting the favorable biological effects of EPA on key steps involved in atherosclerosis, a progressive inflammatory process responsible for adverse cardiovascular outcomes. This review article authored

by Drs. Kenneth M. Borow, John R. Nelson, and R. Preston Mason has recently been published in the journal Atherosclerosis.

Additional studies are

needed to determine if the effects explored in these presentations and publications would have clinically meaningful benefit in the human body.

REDUCE-IT cardiovascular outcomes study continuing on-track

The REDUCE-IT cardiovascular outcomes trial continues on schedule towards anticipated completion in 2017 and publication of results in 2018. The results of

this important trial could lead to improved medical care for tens of millions of patients. Amarin is blinded to the ongoing study results. An interim review by the independent data monitoring committee of the trial s efficacy and safety results

is expected to occur during 2016 upon reaching 60% of the target aggregate number of cardiovascular events. Given the nature

of outcomes studies and the design of REDUCE-IT, management currently believes it likely that the study will run to its completion defined as attainment of 100% of the target 1,612 cumulative

patients with documented primary cardiovascular events. If the study were to be stopped early based on overwhelming efficacy results, Amarin intends to consider the results for potential submission toward an expanded indication for Vascepa.

Thus far, over 7,600 patients have been enrolled in the REDUCE-IT cardiovascular outcomes study representing more than 95% of total targeted enrollment. We

anticipate completing study enrollment near the end of 2015.

Net product revenue for the three months ended June 30, 2015 and 2014 was $17.7 million and $12.6 million, respectively. Net product revenue for the six

months ended June 30, 2015 and 2014 was $33.3 million and $23.6 million, respectively. These increases in product revenue were primarily attributable to increases both in new and recurring prescriptions of Vascepa. In addition, we recognized

licensing revenue of $0.4 million in the six months ended June 30, 2015 related to the Eddingpharm development and commercialization agreement executed in February 2015, for which development continues to track forward consistent with our

expectations. Based upon our current estimates, we anticipate approximately $0.8 million in licensing revenue to be recognized in aggregate during 2015, including the $0.4 million recognized earlier in 2015 with no revenue recognized during the

three months ended June 30, 2015.

Cost of goods sold for the three months ended June 30, 2015 and 2014 was $6.4 million and $5.0 million,

respectively. Cost of goods sold for the six months ended June 30, 2015 and 2014 was $12.0 million and $9.3 million, respectively. Gross margin improved to 64% in the three and six months ended June 30, 2015 as compared to 60% and 61% in

the three and six months ended June 30, 2014, respectively. The improvement in gross margin on product sales was primarily driven by lower unit cost active pharmaceutical ingredient purchases.

Selling, general and administrative, or SG&A, expenses in the six months ended June 30, 2015 and 2014 were $50.8 million and $41.7 million,

respectively. The increase in expenses reflects quarterly variability of certain initiatives; legal costs associated with the successful challenge to FDA s denial of New Chemical Entity designation for Vascepa and the ongoing First Amendment

litigation; the addition of co-promotion fees payable to Kowa Pharmaceuticals America, Inc., which were nominal in the six months ended June 30, 2014 as the Kowa agreement commenced late in this period; and an increase in non-cash stock-based

compensation expense. We anticipate that our level of SG&A expenses will be variable quarter to quarter. We anticipate expanding programs later in 2015 to more broadly educate healthcare professionals about Vascepa, including certain data

regarding the ANCHOR trial based at least on the June 5, 2015 guidance received from the FDA in conjunction with our First Amendment lawsuit. We expect to more fully define the extent of this increase in activity after the court rules on our

request for preliminary relief in our First Amendment litigation. In this lawsuit, we seek the ability to communicate truthful and non-misleading information about Vascepa to healthcare professionals, even though such information is not in the

FDA-approved label for Vascepa. The suit is based on the principle that better informed physicians make better treatment decisions for their patients.

Research and development expenses in the six months ended June 30, 2015 and 2014 were $24.6 million and

$23.4 million, respectively. The increase in expenses was driven by actions to complete patient enrollment in the REDUCE-IT study. Research and development costs are expected to be slightly higher during 2015 as compared to 2014 with quarterly

variability as a result of the timing of REDUCE-IT costs, and such costs are expected to decline modestly thereafter upon completion of enrollment for REDUCE-IT.

Under GAAP, Amarin reported a net loss of $62.9 million in the second quarter of 2015, or basic and diluted loss per share of $0.35. This net loss included

$3.2 million in non-cash share-based compensation expense, a $0.6 million non-cash loss on the change in fair value of derivatives, and a $31.3 million charge for a non-cash deemed dividend for accounting purposes. Amarin reported net income of

$15.3 million in the second quarter of 2014, or basic and diluted earnings per share of $0.09 and $0.08, respectively. This net income included $2.4 million in non-cash share-based compensation expense, $0.1 million in non-cash warrant compensation

income, a $3.0 million gain on the change in fair value of derivatives, and a $38.0 million gain on extinguishment of debt.

Under GAAP, Amarin reported a

net loss of $94.8 million in the six months ended June 30, 2015, or basic and diluted loss per share of $0.53. This net loss included $6.3 million in non-cash share-based compensation expense, a $0.1 million non-cash loss on the change in fair

value of derivatives, and $32.2 million in charges for non-cash deemed dividends for accounting purposes. For the six months ended June 30, 2014, Amarin reported a net loss of $10.7 million, or basic and diluted loss per share of $0.06 and

$0.07, respectively. This net loss included $4.4 million in non-cash share-based compensation expense, $0.2 million in non-cash warrant compensation income, a $7.4 million gain on the change in fair value of derivatives, and a $38.0 million gain on

extinguishment of debt.

Excluding non-cash gains or losses for share-based compensation, warrant compensation, change in fair value of derivatives, and

the non-cash deemed dividend, non-GAAP adjusted net loss was $27.7 million for the second quarter of 2015, or non-GAAP adjusted basic and diluted loss per share of $0.15, compared to non-GAAP adjusted net loss of $23.4 million for the second quarter

of 2014, or non-GAAP adjusted basic and diluted loss per share of $0.14.

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

compensation, change in fair value of derivatives, and the non-cash deemed dividends, non-GAAP adjusted net loss was $56.3 million for the six months ended June 30, 2015, or non-GAAP adjusted basic and diluted loss per share of $0.32, compared

to non-GAAP adjusted net loss of $51.9 million for the six months ended June 30, 2014, or non-GAAP adjusted basic and diluted loss per share of $0.30.

Amarin reported cash and cash equivalents of $136.0 million at June 30, 2015, representing a net increase of $16.5 million from reported cash and cash

equivalents of $119.5 million as of December 31, 2014. The increase was driven by the receipt of a $15.0 million up-front licensing fee and net proceeds from a preferred stock issuance of $52.1 million, partially offset by cash used in

operating activities. Net cash used in operating activities in the six months ended June 30, 2015 included approximately $28.0 million in sales and marketing related expenses and approximately $17.5 million of costs incurred through our

contracted clinical research organization and for clinical trial materials in support of the REDUCE-IT cardiovascular outcomes study.

As of June 30, 2015, Amarin had approximately 183.3 million American Depository Shares (ADSs) and

ordinary shares outstanding, 28.9 million common share equivalents of Series A Convertible Preferred Shares outstanding and approximately 11.8 million equivalent shares underlying stock options at a weighted average exercise price of

$4.44, as well as 4.0 million equivalent shares underlying restricted or deferred stock units.

Conference call and webcast information

Amarin will host a conference call at 4:30 p.m. ET (8:30 p.m. UTC/GMT) today, August 6, 2015. The conference call can be

heard live via the investor relations section of the company s website at www.amarincorp.com, or via telephone by dialing 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 United States) or 201-612-7415 (outside the United States). A replay of the call will also be available through the

company s website shortly after the call. For both dial-in numbers please use conference ID 13614382.

Use of non-GAAP adjusted financial

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.

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, changes in value of derivatives and a non-cash deemed dividend. 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 company s business operations, investors are reminded to consider these non-GAAP measures in addition to, and not as a substitute for, financial performance

measures prepared in accordance with GAAP. Non-GAAP measures have limitations in that they do not reflect all of the amounts associated with the company s results of operations as determined in accordance with GAAP. In addition, it should be

noted that these non-GAAP financial measures may be different from non-GAAP measures used by other companies, and management may utilize other measures to illustrate performance in the future.

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. Amarin s clinical program includes commitment to an ongoing outcomes

study. Amarin s first product, Vascepa (icosapent ethyl) capsules, is a highly pure EPA omega-3 prescription product. For more

information about Vascepa visit www.vascepa.com. For more information about Amarin visit www.amarincorp.com.

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.