Tell your health care provider right away if you have signs of active bleeding (persistent and unexplained) while you are taking DUEXIS.NSAID‐containing medications like DUEXIS can cause high blood pressure or make existing high blood pressure worse, either of which can increase the chance of a heart attack or stroke. Your health care provider should check your blood pressure while you are taking DUEXIS. Before you start taking DUEXIS, tell your health care provider if you have heart problems, kidney problems, or liver problems, or if you are taking medications for high blood pressure. DUEXIS can increase the chance of potentially significant liver injury and/or kidney injury, which may be fatal. Stop taking DUEXIS immediately and contact your health care provider if you experience any signs and/or symptoms of liver or kidney injury. Serious allergic reactions, including skin reactions, can happen without warning and can be life threatening. Stop taking DUEXIS and consult your doctor immediately if you get a skin rash or if you start to have problems breathing or swallowing, or if you develop swelling of your face or throat. The most common side effects of DUEXIS include nausea, diarrhea, constipation, upper abdominal pain, and headache. Please see Medication Guide and full Prescribing Information. About Horizon Pharma Horizon Pharma, Inc. is a biopharmaceutical company that is developing and commercializing innovative medicines to target unmet therapeutic needs in arthritis, pain and inflammatory diseases. For more information, please visit www.horizonpharma.com. Forward-Looking Statements This press release contains forward-looking statements, including statements regarding future activities conducted under the co-promotion agreement, the potential benefits of the co-promotion agreement, including benefits to the commercial launch of DUEXIS and increasing revenues from DUEXIS sales, the timing of Mallinckrodt's promotional efforts and Horizon's plans to expand its sales force. 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 each party's performance of its respective obligations under the co-promotion agreement, the ability of each party's sales force to successfully promote and commercialize DUEXIS, the parties' ability to successfully collaborate with one another under the co-promotion agreement regarding sales and marketing plans and strategy, the parties' ability to terminate the co-promotion agreement, existing competition for DUEXIS in the U.S., the extent to which healthcare professionals will prescribe DUEXIS and the extent to which such prescriptions result in actual sales and other factors described in Horizon's filings with the United States Securities and Exchange Commission, including those factors discussed under the caption "Risk Factors" in those filings. Forward-looking statements speak only as of the date of this press release, and Horizon undertakes no obligation to update or revise these statements, except as may be required by law. Contacts Timothy P. WalbertChairman, President and Chief Executive Officer firstname.lastname@example.org Media Geoff CurtisDJE Science312-550-8138 email@example.com Investors Kathy GalanteBurns McClellan, Inc.212-213-0006 firstname.lastname@example.org SOURCE Horizon Pharma, Inc.