Horizon Pharma plc. Announces Favorable Markman Ruling in RAYOS® (prednisone) Delayed-Release Tablets Patent Infringement Litigation

DUBLIN, IRELAND--(Marketwired - November 12, 2014) - Horizon Pharma plc (NASDAQ: HZNP), a specialty biopharmaceutical company with a portfolio of products in arthritis, inflammation and orphan diseases, today announced that a favorable Markman ruling has been issued by Judge Joseph E. Irenas of the United States District Court for the District of New Jersey in the patent infringement lawsuit filed by Horizon against Watson Laboratories, Inc. for an Abbreviated New Drug Application ("ANDA") to market a generic version of RAYOS.

A Markman ruling, also known as a Claim Construction Ruling, is a determination by the court of the meaning and scope of disputed patent claim terms of certain patents in suit. Judge Irenas was asked to construe disputed claim terms in U.S. Patent No. 8,394,407 and U.S. Patent No. 8,309,124 and adopted Horizon's proposed construction of both of the disputed claim terms.

"We are pleased with the Court's ruling and remain confident that our intellectual property will continue to provide long-term commercial exclusivity for RAYOS," said Timothy P. Walbert, chairman, president and chief executive officer, Horizon Pharma plc.

About RAYOS®
RAYOS, known as LODOTRA® in Europe, is a proprietary delayed-release formulation of low-dose prednisone. The pharmacokinetic profile of RAYOS is different with an approximately four-hour lag time from that of immediate-release prednisone formulations. In clinical trials studying use of RAYOS in rheumatoid arthritis (RA), patients were administered RAYOS at 10 p.m. with food. The delayed-release profile of RAYOS helps to achieve therapeutic prednisone blood levels at a time point when cytokine levels start rising during the middle of the night. While the pharmacokinetic profile of RAYOS differs in terms of lag time from immediate-release prednisone, its absorption, distribution and elimination processes are comparable. For more information, please visit www.RAYOSrx.com.

RAYOS utilizes Skyepharma's proprietary Geoclock™ technology.

Outside the United States, LODOTRA is approved for the treatment of moderate to severe active RA in adults particularly when accompanied by morning stiffness in over thirty-five countries. Horizon has granted commercialization rights for LODOTRA in Europe, Asia (excluding Japan) and Latin America to its distribution partner Mundipharma International Corporation Limited. Horizon has an exclusive license from Skyepharma for RAYOS/LODOTRA.

Approved Uses for RAYOS
RAYOS, a delayed-release form of prednisone, prevents the release of substances in the body that cause inflammation. RAYOS is approved to treat a broad range of diseases including RA, polymyalgia rheumatica (PMR), psoriatic arthritis (PsA), ankylosing spondylitis (AS), asthma and chronic obstructive pulmonary disease (COPD). For a full list of RAYOS indications, please see full prescribing information at www.RAYOSrx.com. RAYOS is contraindicated in patients who have known hypersensitivity to prednisone or to any of the excipients. Rare instances of anaphylaxis have occurred in patients receiving corticosteroids.

Important Safety Information about RAYOS
Do not use RAYOS if you are allergic to prednisone. Long-term use of RAYOS can affect how your body responds to stress. Symptoms can include weight gain, severe fatigue, weak muscles and high blood sugar. RAYOS can weaken your immune system, making it easier for you to get an infection or worsening an infection you already have or have recently had. RAYOS can cause high blood pressure, salt and water retention and low blood potassium. There is an increased risk of developing holes in the stomach or intestines if you have certain stomach and intestinal disorders. Behavior and mood changes can occur, including intense excitement or happiness, sleeplessness, mood swings, personality changes or severe depression.

Long-term use of RAYOS can cause decreases in bone density. RAYOS can cause cataracts, eye infections and glaucoma. Do not receive a "live" vaccine while taking RAYOS. The vaccine may not work as well during this time and may not fully protect you from disease. Taking RAYOS during the first trimester of pregnancy can harm an unborn baby. Long-term use of RAYOS can slow growth and development in children.

The most common side effects with RAYOS are water retention, high blood sugar, high blood pressure, unusual behavior and mood changes, increased appetite and weight gain. Please see full prescribing information for RAYOS at www.RAYOSrx.com.

About Horizon Pharma plc
Horizon Pharma plc is a specialty biopharmaceutical company focused on improving patients' lives by identifying, developing, acquiring and commercializing differentiated products that address unmet medical needs. The Company markets a portfolio of products in arthritis, inflammation and orphan diseases. Horizon's U.S. marketed products are ACTIMMUNE® (interferon gamma-1b), DUEXIS® (ibuprofen/famotidine), RAYOS® (prednisone) delayed-release tablets and VIMOVO® (naproxen/esomeprazole magnesium). Beginning in January 2015, the Company expects to begin marketing PENNSAID® (diclofenac sodium topical solution) 2% w/w in the United States. Horizon's global headquarters are in Dublin, Ireland. For more information, please visit www.horizonpharma.com.

About Skyepharma PLC
Skyepharma combines proven scientific expertise with validated proprietary drug delivery technologies to develop innovative oral and inhalation pharmaceutical products. The Group is eligible for revenues from 16 approved products in the areas of inhalation, oral, topical and injectable drug delivery as well as generating income from the development of further products and technology licenses. The products developed by the Group are marketed throughout the world by big pharma as well as specialty pharmaceutical companies. For more information, visit www.skyepharma.com.

Forward-Looking Statements
This press release contains forward-looking statements, including statements about whether existing patents will provide long-term commercial exclusivity for RAYOS. These forward-looking statements are based on management's expectations and assumptions as of the date of this press release, and actual results may differ materially from those in these forward-looking statements as a result of various factors. These factors include risks regarding sufficient protection and market exclusivity for RAYOS, whether the patents issued to or licensed by Horizon may be challenged, invalidated, infringed or circumvented by third parties, and other factors described in Horizon's filings with the United States Securities and Exchange Commission. Additional risks and uncertainties relating to Horizon Pharma plc and its business can be found under the caption "Risk Factors" and elsewhere in Horizon Pharma plc's Securities and Exchange Commission filings and reports, including in its Quarterly Report on Form 10-Q for the quarter ended September 30, 2014. Forward-looking statements speak only as of the date of this press release, and Horizon Pharma plc undertakes no duty or obligation to update any forward-looking statements contained in this release as a result of new information, future events or changes in its expectations.