Amarin Reports Third Quarter 2015 Financial Results and Provides Update on Operations - REDUCE-IT cardiovascular outcomes study progressing as planned - - Net product revenue increased 51% over same period last year - -

Amarin Reports Third Quarter 2015 Financial Results

and Provides Update on Operations

- REDUCE-IT cardiovascular outcomes study progressing as planned -

- Net product revenue increased 51% over same period last year -

- Conference Call Set for 8:00 a.m. ET Today -

BEDMINSTER, N.J., and DUBLIN, Ireland, November 4, 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 nine months ended September 30, 2015, and provided an update on company operations.

Key Amarin achievements since June 30, 2015 include:

continues to make important strides, including increased revenues from Vascepa, expanded ability to promote Vascepa, and continued progress on the first ever cardiovascular outcomes study designed to evaluate the efficacy and safety of Vascepa

treatment on top of statin therapy in reducing cardiovascular mortality and morbidity in high-risk patients with above normal triglyceride levels, stated John F. Thero, President and Chief Executive Officer of Amarin. He added that, We

are increasingly bullish in the potential for use of Vascepa to grow and we continue to believe that REDUCE-IT is positioned for success leading to a dramatically larger opportunity for Vascepa and for the improved care of patients.

Commercialization update United States

Revenue growth in the third quarter of 2015 primarily resulted from increased shipment volumes of Vascepa to wholesalers in support of increased reorders and

new orders of Vascepa. The average net

price of Vascepa sold in Q3 2015 was lower than in Q3 2014 but approximated the net price in Q2 2015. As previously discussed, average net pricing in 2015 reflects additional rebates as a result

of broader managed care coverage that was partially offset by the impact of a 6% price increase in Q2 2015.

Normalized prescriptions (estimated) for the

third quarter of 2015, based on data from Symphony Health Solutions and IMS Health, totaled approximately 199,000 and 176,000, respectively. These prescription levels represent growth of approximately 13% and 12%, respectively, compared to the

quarter ended June 30, 2015, and an increase of approximately 51% and 56%, 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.

Expanded ability to promote Vascepa

As announced in August 2015, a United States District Court granted Amarin s request for preliminary relief and confirmed that Amarin may engage in

truthful and non-misleading speech promoting Vascepa to healthcare professionals beyond the use approved by the FDA, with specific reference to patients studied in Amarin s successful ANCHOR study of Vascepa, i.e., patients with persistently

high triglycerides after statin therapy, and that such speech may not form the basis of a misbranding action under the Federal Food and Drug Cosmetic Act. FDA did not appeal the Court s preliminary ruling. The underlying litigation has been

stayed for settlement discussion and the parties are working toward settlement.

While not the same as an FDA-approved label change, the Court declaration

allows promotion to healthcare professionals of the FDA-reviewed and agreed effects of Vascepa demonstrated in the ANCHOR clinical trial of patients with persistently high triglycerides after statin therapy and use of peer-reviewed scientific

publications that present the current state of scientific research related to the potential of Vascepa to reduce the risk of cardiovascular disease. Amarin believes that this Court decision will lead to improved patient care. The decision opens more

direct and effective paths to communicate truthful and non-misleading information about Vascepa clinical trial results and the state of science relevant to the potential of Vascepa to reduce the risk of cardiovascular disease. With accurate

information readily available, healthcare professionals will be more able to assess for themselves how best to choose among available treatment options for their patients.

Beginning in mid-August, Amarin began educating select healthcare professionals on results from its successful Phase 3 ANCHOR clinical trial in which Vascepa,

compared to placebo, improved triglyceride levels and various other lipid and lipoprotein biomarkers without increasing low-density lipoprotein cholesterol (LDL-C) in statin-treated patients with persistently high triglyceride levels (200-499

mg/dL). This education includes promotion of published data from the ANCHOR study together with disclosures designed to ensure the information communicated is not misleading, as described by Amarin at the time of the Court declaration.

Preliminary feedback from healthcare professionals suggests that they appreciate the information and that for most of them the information is completely new.

Prescription levels for Vascepa were growing in July and August before this new information was presented to select healthcare professionals. As of September 30, 2015, the 20,000 physicians who are the top targets for prescribing Vascepa had

called upon by Amarin representatives fewer than two times on average. While promotion of the ANCHOR trial results may have had some positive impact on September prescription levels, the level of

such impact is believed to be limited and it is not yet possible to accurately quantify the future impact on prescription growth from this expanded ability to promote ANCHOR clinical data and research on the potential connection between Vascepa and

cardiovascular risk reduction.

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. Completion of the

REDUCE-IT study is based on attainment of 1,612 cumulative patients with documented primary cardiovascular events. 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 (DMC) 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. Based on comprehensive review of clinical, epidemiological, and genetic data, Amarin continues to believe that REDUCE-IT is

positioned for success at completion. Given the high thresholds of overwhelming efficacy and safety typically required to be achieved prior to an independent DMC recommending an early stop to a cardiovascular outcomes trial like REDUCE-IT,

management continues to believe that it is most likely that the REDUCE-IT study will run to its completion.

More than 7,700 patients have been enrolled

in the REDUCE-IT cardiovascular outcomes study representing more than 97% of total targeted patient enrollment in this event-driven study.

Net product revenue for the

three months ended September 30, 2015 and 2014 was $21.3 million and $14.1 million, respectively. Net product revenue for the nine months ended September 30, 2015 and 2014 was $54.6 million and $37.7 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 $0.5 million in the nine months ended September 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.

We anticipate that our current marketing activities combined with our expanded ability to promote Vascepa will

contribute to increasing Vascepa revenues. We anticipate that most of the effect of our expanded ability to promote Vascepa will occur beyond 2015 as it requires time to effectively educate healthcare professionals on new clinical data, particularly

when the volume of such data and related disclosures is extensive and communicated without a change in the product s approved label. Based on data currently available, we estimate that we will recognize net product revenues of $22.5 million to

$24.0 million in Q4 2015 resulting in net product revenues of $77.1 million to $78.6 million for the year ended December 31, 2015.

Cost of goods sold for the three months ended September 30, 2015 and 2014 was $7.5 million and $5.4 million,

respectively. Cost of goods sold for the nine months ended September 30, 2015 and 2014 was $19.5 million and $14.6 million, respectively. Gross margin on product sales improved to 65% and 64% in the three and nine months ended

September 30, 2015, respectively, as compared to 62% and 61% in the three and nine months ended September 30, 2014, respectively. The improvement in gross margin on product sales was primarily driven by lower unit cost active

pharmaceutical ingredient purchases. We received initial batches of API from our newest supplier in Q3 2015 and anticipate that, based on competitive pricing from this supplier and our other suppliers, gross margins should continue to improve,

particularly as we progress through 2016.

Selling, general and administrative, or SG&A, expenses in the nine months ended September 30, 2015 and

2014 were $77.5 million and $60.9 million, respectively. The increase in expenses was primarily driven by higher co-promotion fees payable to Kowa Pharmaceuticals America, Inc. due to increased revenues and the partnership not commencing until

mid-Q2 2014, higher sales and marketing costs primarily associated with the recent Federal court decision permitting us to promote to healthcare professionals certain truthful and non-misleading information about the potential benefits of Vascepa,

an increase in non-cash stock-based compensation expense, and higher legal fees.

Research and development expenses in the nine months ended

September 30, 2015 and 2014 were $37.7 million and $37.9 million, respectively. Research and development costs are expected to reflect quarterly variability as a result of the timing of REDUCE-IT costs, and overall such costs are expected to

decline modestly upon completion of enrollment for REDUCE-IT.

Under GAAP, Amarin reported a net loss of $32.3 million in the third quarter of 2015, or

basic and diluted loss per share of $0.18. This net loss included $3.9 million in non-cash share-based compensation expense, a $0.2 million non-cash loss on the change in fair value of derivatives, and a $1.6 million charge for a non-cash deemed

dividend for accounting purposes. Amarin reported a net loss of $26.1 million in the third quarter of 2014, or basic and diluted loss per share of $0.15 and $0.17, respectively. This net loss included $1.9 million in non-cash share-based

compensation expense, $0.3 million in non-cash warrant compensation income and a $4.5 million gain on the change in fair value of derivatives.

GAAP, Amarin reported a net loss of $127.2 million in the nine months ended September 30, 2015, or basic and diluted loss per share of $0.71. This net loss included $10.2 million in non-cash share-based compensation expense, a $0.4 million

non-cash loss on the change in fair value of derivatives, and $33.9 million in charges for non-cash deemed dividends for accounting purposes. For the nine months ended September 30, 2014, Amarin reported a net loss of $36.7 million, or basic

and diluted loss per share of $0.21 and $0.25, respectively. This net loss included $6.3 million in non-cash share-based compensation expense, $0.5 million in non-cash warrant compensation income, an $11.9 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 $26.5 million for the third quarter of 2015, or non-GAAP adjusted basic and diluted loss per share of $0.14 compared to non-GAAP adjusted net loss

of $28.9 million for the third quarter of 2014, or non-GAAP adjusted basic and diluted loss per share of $0.17.

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 $82.8 million for the nine months ended September 30, 2015, or non-GAAP adjusted basic and diluted loss per share of $0.46, compared to non-GAAP adjusted net loss of

$80.8 million for the nine months ended September 30, 2014, or non-GAAP adjusted basic and diluted loss per share of $0.47.

Amarin reported cash and

cash equivalents of $119.0 million at September 30, 2015, representing a net decrease of $0.5 million from reported cash and cash equivalents of $119.5 million as of December 31, 2014. The change in cash balance reflects the receipt of a

$15.0 million up-front licensing fee and net proceeds from preferred stock issuances of $57.7 million, offset by cash used in operating activities. Net cash used in operating activities in the nine months ended September 30, 2015 included

approximately $40.5 million in sales and marketing related expenses and approximately $28.4 million of costs incurred through our contracted clinical research organization and for clinical trial materials in support of the REDUCE-IT cardiovascular

outcomes study. During 2015, cash used for operating activities in the nine months ended September 30, 2015, included approximately $20 million more for supply purchases than used during the corresponding period of 2014 as Amarin commenced

2014, for reasons previously described, with higher than needed inventory levels.

As of September 30, 2015, Amarin had approximately

183.3 million American Depository Shares (ADSs) and ordinary shares outstanding, 32.8 million common share equivalents of Series A Convertible Preferred Shares outstanding and approximately 17.6 million equivalent shares underlying

stock options at a weighted average exercise price of $3.78, as well as 11.0 million equivalent shares underlying restricted or deferred stock units.

Conference call and webcast information

Amarin will host a conference call at 8:00 a.m. ET (1:00 p.m. UTC/GMT) today, November 4, 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 13621865.

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.