Amarin Reports Second Quarter 2014 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 2014 Financial Results

and Provides Update on Operations

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

BEDMINSTER, N.J., and DUBLIN, Ireland, August 7, 2014 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 quarter and six months ended June 30, 2014, and provided an update on company operations.

Key Amarin achievements since March 31, 2014 include:

Financially, operationally and strategically we made important progress in Q2 2014 all of which should position Amarin for further growth, stated

John F. Thero, President and Chief Executive Officer. He added that, While it is too early to expect significant prescription growth from Kowa s co-promotion efforts, since mid-May they have become increasingly active in educating target

physicians about Vascepa. These co-promotion efforts should add further positive momentum to the increasing prescription trends we witnessed in Q2 from customers we targeted with our sales team.

The FDA s Office of New Drugs recently notified Amarin that it requires additional time to respond to the company s appeal of the rescission of the

ANCHOR clinical trial special protocol assessment agreement. Amarin now expects to receive a substantive response to its appeal by mid-September.

Commercialization update

Amarin s sales representatives in Q2 continued their focus on educating a select group of the highest potential target physicians on the benefits of

Vascepa, with both new and recurring prescriptions continuing to increase from these targets.

As expected, Kowa Pharmaceuticals America s sales team

was trained and began co-promotion of Vascepa by the end of May. This co-promotion arrangement is structured to more than double the sales detail levels from that which Amarin s sales team has achieved on its own, including details to more than

twice the number of physicians currently targeted by Amarin s sales representatives. These co-promotion activities are intended to build on the positive recent prescription trends generated by Amarin s sales representatives. As is typical

for sales representatives promoting a new product, particularly when that product is a therapy for a chronic condition, it takes time for the effect of the co-promotion to take root and impact prescription growth.

Normalized prescriptions (estimated) for the quarter ended June 30, 2014, based on data from Symphony Health Solutions and IMS Health, totaled

approximately 110,000 and 93,000, respectively, and grew approximately 18% and 19%, respectively, compared to the quarter ended March 31, 2014. Such prescription growth was primarily generated from higher decile physicians targeted by

Amarin s sales representatives.

During Q2, the prescription drug that most closely competes with Vascepa became generic. Generic forms of this

competitive drug are currently priced such that they are more expensive than is Vascepa under most managed care plans. After such generic launch, formulary access to Vascepa, including Tier 2 coverage, continued to improve.

In addition to sales promotion activities, in Q2 2014, Amarin executed multiple initiatives to increase awareness of the efficacy and safety profile of

Vascepa and to highlight the need for patients with very high triglycerides to be treated by physicians. In June 2014, Amarin commenced a national partnership with Rick Harrison, star of the hit television show, Pawn Stars , in launching Lower My Trigs , a national awareness campaign about seeking treatment for very high triglycerides. Amarin engaged Harrison as a spokesperson for the campaign to

inform patients and family members, their physicians and other health care professionals about the health risks of very high triglycerides and the importance of patients discussing available treatment options with their physician.

Physician experience with Vascepa continues to increase, and Amarin continues to receive overwhelmingly positive feedback from clinicians and patients

regarding the treatment effects of Vascepa. Dr. Richard S. Castaldo, a physician who practices medicine in Upstate New York, recently authored a hypothesis generating publication, titled A Retrospective Case Series of the Lipid

Effects of Switching from Omega-3 Fatty Acid Ethyl Esters to Icosapent Ethyl in Hyperlipidemic Patients, that is available electronically through Postgraduate Medicine (available at:

https://postgradmed.org/doi/10.3810/pgm.2014.05.2775). In this publication, 14 patient cases were

reviewed for hyperlipidemic patients who switched to treatment with Vascepa from a competitive omega-3 therapy, a mixture which contains DHA in addition to other components. As documented in the

publication, most of the switched patients experienced improvements in triglyceride and low-density lipoprotein cholesterol (LDL-C) levels. This publication and others to potentially follow are the product of company-funded efforts directed to

generating additional data on the clinical effects of Vascepa in the future. Since approval, many clinicians have increasingly expressed interest in researching and publishing data reflecting their real-world experience with Vascepa.

Amarin reported cash and cash

equivalents of $150.5 million at June 30, 2014, representing a net decrease of $13.8 million from reported cash and cash equivalents of $164.3 million as of March 31, 2014 and a net decrease of $41.0 million from reported cash and cash

equivalents of $191.5 million as of December 31, 2013. Net cash outflows in the six months ended June 30, 2014 included approximately $24.7 million in sales and marketing related expenses and approximately $16.7 million of costs incurred

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

improvement in net cash outflow from operations to $11.3 million in Q2 2014 compared to $27.5 million in Q1 2014 and $52.8 million in Q2 2013 reflects the company s focus on cash preservation and targeting spend efficiently in order to maximize

Vascepa revenues and minimize cash burn. While the company expects its cash flow from operations to continue improving overall, it is anticipated that the company will experience fluctuations in quarterly net cash outflows. As a result of the timing

of certain items, including, most significantly, interest payments and supply purchases, the company anticipates that Q3 net cash outflows from operations will exceed Q2 net cash outflows. The company continues to estimate that, during 2014, net

cash outflows will be less than $80 million.

Net product revenues for the three months ended June 30, 2014 and 2013 were $12.6 million and $5.5

million, respectively. Net product revenues for the six months ended June 30, 2014 and 2013 were $23.6 million and $7.8 million, respectively. These increases in product revenues are attributable to increases both in new and recurring

prescriptions of Vascepa.

Cost of goods sold for the three months ended June 30, 2014 and 2013 was $5.0 million and $2.8 million, respectively. Cost

of goods sold for the six months ended June 30, 2014 and 2013 was $9.3 million and $4.1 million, respectively. Gross margin improved to 60% and 61% in the three and six months ended June 30, 2014 as compared to 48% and 47% in the three and

six months ended June 30, 2013. The improvement in gross margins in 2014 was primarily driven by lower unit cost active pharmaceutical ingredient, or API, purchases.

Under GAAP, 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. 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 and $0.34, respectively. This net loss included $5.1 million in non-cash share-based compensation

expense, $1.0 million in non-cash warrant compensation income, and an $18.8 million gain on the change in the fair value of derivatives.

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. 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 and $0.77, respectively. 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.

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

non-GAAP adjusted net loss was $23.4 million for the first quarter of 2014, or non-GAAP adjusted basic and diluted loss per share of $0.14, as compared to non-GAAP adjusted net loss of $54.5 million for the three months ended June 30, 2013, or

non-GAAP adjusted basic and diluted loss per share of $0.36. Adjusted net loss was $51.9 million for the six months ended June 30, 2014, or non-GAAP adjusted basic and diluted loss per share of $0.30, as compared to adjusted net loss of $115.9

million for the six months ended June 30, 2013, or non-GAAP adjusted basic and diluted loss per share of $0.77.

Amarin s liabilities as of

June 30, 2014, excluding the fair value of the non-cash warrant derivative liability, totaled approximately $251.3 million, which includes $122.5 million for the carrying value of exchangeable debt and $94.8 million for the carrying value of

the hybrid debt-like financing that we entered into in December 2012.

As of June 30, 2014, Amarin had approximately 172.9 million American

Depository Shares (ADSs) and ordinary shares outstanding as well as approximately 9.8 million and 11.9 million equivalent shares underlying warrants and stock options, respectively, at average exercise prices of $1.41 and $5.47,

respectively, and 2.3 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 7, 2014. 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 13586651.

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 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. Vascepa (icosapent ethyl),

Amarin s first FDA approved product, is an ultra-pure, omega-3 fatty acid product available by prescription. 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.

Indications and Usage

Important Safety Information for Vascepa

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

Vascepa has been approved for use by the FDA as an adjunct to diet to reduce triglyceride levels in adult patients with severe (>500 mg/dL)

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

that has not been approved by the FDA.

Forward-looking statements

This press release contains forward-looking statements, including statements about the future commercialization of Vascepa, including the continued expansion

of promotional efforts resulting from the co-promotion agreement with Kowa Pharmaceuticals America, the anticipated increase in prescriptions, expectations for revenue growth, product awareness, receptivity of clinicians to and patient experience

with Vascepa; expectations regarding managed care coverage migration from Tier 3 to Tier 2 and continued growth in Tier 2 coverage; the pricing terms of commercial supply for Vascepa; expectations regarding cash burn, gross margins and cost of goods

sold; the likelihood of becoming cash flow positive; the FDA review of Amarin s SPA rescission appeal and Amarin efforts related to such interactions; the efficacy, safety and therapeutic benefits of Vascepa; the ability of Amarin to continue

the REDUCE-IT study in light of company resources and other factors; and continued enrollment and following of patients in Amarin s REDUCE-IT cardiovascular outcomes study. These forward-looking statements are not promises or guarantees and

involve substantial risks and uncertainties. In particular, as disclosed in its previous filings with the U.S. Securities and Exchange Commission, Amarin s ability to effectively commercialize Vascepa will depend in part on efforts of third

parties, its ability to create market demand for Vascepa through education, marketing and sales activities, to achieve market acceptance of Vascepa, to receive adequate levels of reimbursement from third-party payers, to develop and maintain a