Horizon Pharma, Inc., a commercial stage, specialty pharmaceutical company,  and Vidara Therapeutics International Ltd. (Vidara) have entered into a definitive agreement under which Horizon Pharma will acquire Vidara through a reverse merger for stock and cash valued at approximately $660 million. Horizon Pharma plc will be the name of the resulting company. Horizon Pharma plc will be organized under the laws of Ireland with a portfolio of four products marketed primarily in the United States. The proposed transaction has been unanimously approved by both companies' boards of directors.

Pursuant to the agreement, Vidara will combine with Horizon Pharma, Inc. with approximately 74 per cent of Horizon Pharma plc's ordinary shares to be exchanged for Horizon Pharma, Inc.'s common shares, with Horizon surviving the merger. The shareholders of Vidara will retain approximately 26 per cent of Horizon Pharma plc and receive $200 million in cash, subject to certain adjustments.

Strategic and financial benefits of the transaction: Accelerated transformation of Horizon to a profitable specialty pharma company;  Expected pro forma combined, full year 2014 revenues of $250 to $265 million and EBITDA of $65 to $75 million;   Expanded revenue base to include Horizon Pharma's Duexis, Vimovo and Rayos marketed in the US, Vidara's Actimmune marketed in the US and Horizon's Lodotra marketed outside the US; Tax efficient corporate structure enhanced to support Horizon's organic growth and acquisition strategy.

"The addition of Actimmune complements our commercial business model focused on targeted promotion to primary care physicians and specialists," said Timothy P. Walbert, chairman, president and chief executive officer, Horizon Pharma. "The combined company would have a portfolio of four proprietary products and an international platform that builds on our strategy of organic growth and acquisitions. We look forward to working with the Vidara team to bring our companies together to accelerate the creation of shareholder value."

Vidara is a privately-held, profitable specialty pharmaceutical company with operations in Dublin, Ireland and the US. The company markets Actimmune, a bioengineered form of interferon gamma-1b, a protein that acts as a biologic response modifier, in the US. Actimmune is approved by the US Food and Drug Administration (FDA) for use in children and adults with chronic granulomatous disease (CGD) and severe, malignant osteopetrosis (SMO). Actimmune is indicated for reducing the frequency and severity of serious infections associated with CGD and for delaying time to disease progression in patients with SMO.

In the proposed transaction, stockholders of Horizon Pharma, Inc. would own approximately 74 per cent of Horizon Pharma plc and Vidara shareholders would own approximately 26 per cent. Stockholders of Horizon Pharma, Inc. would receive one ordinary share of Horizon Pharma plc in exchange for each share of Horizon Pharma, Inc. common stock they own at closing. The combined company is expected to have a capitalization of approximately 100 million basic and 122 million fully diluted shares. Horizon Pharma plc would be a US Securities and Exchange Commission reporting company, and its ordinary shares would trade on NASDAQ. The transaction will be taxable to the Horizon Pharma, Inc. US stockholders.

Horizon Pharma has secured a $250 million bridge loan commitment from Deerfield Management Company, L.P., pending execution of its final financing plans.

Timothy P Walbert, chairman, president and chief executive officer of Horizon Pharma, Inc. would be chairman, president and chief executive officer of Horizon Pharma plc and current officers of Horizon Pharma, Inc. would be officers of Horizon Pharma plc. Vidara executives would join Horizon Pharma plc in important leadership and management roles within the combined company.

The transaction, which has been approved by the boards of directors of both companies, is subject to approval by the stockholders of Horizon Pharma, Inc. and the satisfaction of customary closing conditions and regulatory approvals, including antitrust approval in the US The transaction is expected to close mid-year 2014.

Certain affiliates of Horizon Pharma, Inc., who hold approximately 20 per cent of the outstanding shares of common stock of Horizon Pharma, Inc., have agreed to vote in favour of and take necessary actions on matters related to the transaction described in this press release. Shareholders who hold > 95% of the shares of Vidara have agreed to vote in favour of and take necessary actions to approve the transaction.

Citigroup Global Markets Inc. is acting as lead financial advisor to Horizon Pharma and JMP Securities LLC is acting as co-financial advisor for the transaction. The Company's legal advisors are Cooley LLP and McCann FitzGerald (Dublin) and its tax advisors are KPMG LLP. Horizon Pharma's advisors for the related financing transaction are Citigroup Global Markets Inc. and Cowen and Company.

Vidara's financial advisor for the transaction is Lazard Middle Market and its legal advisors are Mayer Brown LLP, Burke Warren McKay and Serritella PC and A&L Goodbody (Dublin).