Horizon Pharma plc Has Commenced Solicitation of Depomed, Inc. Shareholders for Calling of Special Meetings

Proposals to Be Considered Include Removal and Replacement of Entire Depomed Board of Directors and Repeal of Depomed, Inc.’s Recently Adopted Bylaw Amendments

Horizon Pharma plc (NASDAQ: HZNP) (“Horizon Pharma”), a biopharmaceutical company focused on improving patients’ lives by identifying, developing, acquiring and commercializing differentiated and accessible medicines that address unmet medical needs, announced that it has commenced mailing solicitation materials to Depomed, Inc.

(“Depomed”) shareholders, including a definitive solicitation statement previously filed with the U.S. Securities and Exchange Commission (the “SEC”) on September 8, 2015 and a special letter, in connection with Horizon Pharma’s efforts to call two related special meetings of Depomed shareholders.

As previously announced, on September 8, 2015, Horizon Pharma has also separately commenced an exchange offer to acquire all issued and outstanding shares of Depomed common stock. Under the terms of the exchange offer, each holder of Depomed common stock will have the right to receive 0.95 Horizon Pharma ordinary shares for each of their Depomed shares, which exchange ratio was based on a $33.00 per share offer price for Depomed stock and 15-day volume weighted average price of Horizon Pharma ordinary shares as of August 12th, 2015 of $34.74. The exchange offer, however, is conditioned on, among other things, the withdrawal or invalidation of Depomed’s poison pill noted below.

A copy of Horizon Pharma’s solicitation statement and special letter, as well as the documents related to the exchange offer, are viewable at: www.HorizonAndDepomed.com, a website that Horizon Pharma launched to provide details and other relevant information regarding its proposals for the special meetings.

The special letter outlines, among other things, the compelling reasons why Horizon Pharma believes a strategic combination of Horizon Pharma and Depomed would be in the best interests of Depomed shareholders. The accompanying solicitation statement, which includes WHITE and BLUE proxy cards, provides a means for Depomed shareholders to simultaneously join Horizon Pharma in calling two related special meetings to consider and vote on Horizon Pharma’s proposals to remove and replace all of the current Depomed directors and to repeal a series of recent amendments to Depomed’s bylaws.

The WHITE proxy card will authorize Horizon Pharma to request the calling of a special meeting on Depomed shareholders’ behalf to remove the current Depomed directors and to effect the bylaw repeal.

The BLUE proxy card will authorize Horizon Pharma to request the calling of a special meeting on Depomed shareholders’ behalf to replace the current Depomed directors, if removed, with a slate of Horizon Pharma’s nominees.

If a Depomed shareholder does not wish to join Horizon Pharma in calling for the special meetings, no action on the shareholder’s part is required with respect to the proxy cards.

“We urge all Depomed shareholders to support the proxy solicitation by submitting their WHITE and BLUE proxy cards and, ultimately, to take part in the special meetings,” said Timothy P. Walbert, chairman, president and chief executive officer of Horizon Pharma plc. “We believe that Depomed shareholders need to send a message to their board for failing to meaningfully engage with us regarding our many attempts at entering into friendly dialogue regarding a combination of our two companies.”

Under Depomed’s charter and bylaws, shareholders owning 10 percent or more of Depomed’s common stock have the right to call a special meeting. Horizon Pharma, which currently owns approximately 3.73 percent of Depomed’s common shares, intends to solicit other shareholders to meet and exceed that threshold.

Once the special meetings are called, Horizon Pharma would provide proxy materials for voting on such proposals at the special meetings and then solicit revocable proxies for votes on its proposals. At the special meetings, Depomed shareholders would be permitted to vote in favor of all, some or none of Horizon Pharma’s proposals. Neither the calling of special meetings nor the approval by Depomed shareholders of any of the proposals at the special meetings would ensure that Depomed pursues or consummates the proposals that Horizon Pharma has made or any other business combination with Horizon Pharma.

Depomed has unilaterally rejected each of Horizon Pharma’s acquisition offers and declined to engage in meaningful dialogue. Since Horizon Pharma made public its offer to acquire Depomed in an all-stock transaction on July 7, 2015, Depomed’s board of directors has:

Amended Depomed’s bylaws to hinder and delay the calling of a special meeting of shareholders; and,

Put in place a so-called “poison pill” that limits the rights of shareholders to maximize the value of their investment.

“Depomed’s continued refusal to engage with us in meaningful dialogue, even as we present a proposal that featured a 60-percent premium to Depomed’s unaffected stock price as of July 6, 2015 and an approximately 32 percent ownership stake in the combined company, leaves us in a position whereby it is important for us to call for these Special Meetings to elect a new independent Depomed board and remove obstacles to shareholder action,” Walbert continued. “That said, we have always been and continue to be willing to sit down with Depomed’s current board and/or their advisors to begin discussions that could lead to a consensual transaction and avoid this unnecessary process.”