Mast Therapeutics, Inc. (NYSEMKT:MSTX) Files An 8-K Other Events
Item 8.01 Other Events.

As previously announced, on January 6, 2017, Mast Therapeutics, Inc. (the “Company”), Victoria Merger Corp., a wholly-owned subsidiary of the Company (“Merger Sub”), and Savara Inc. (“Savara”) entered into an Agreement and Plan of Merger and Reorganization (“Merger Agreement”), to which, among other things, subject to the satisfaction or waiver of the conditions set forth in the Merger Agreement, Merger Sub will merge with and into Savara (the “Merger”), with Savara becoming a wholly-owned subsidiary of the Company and the surviving corporation of the merger.

Attached hereto as Exhibit 99.1 is a transcript of the joint conference call held on January 9, 2017 by the Company and Savara. Exhibit 99.1 is incorporated by reference herein.

The Company makes no admission as to the materiality of any information in this report. The information contained herein is intended to be considered in the context of the Company’s filings with the Securities and Exchange Commission and other public announcements that the Company makes, by press release or otherwise, from time to time. The Company undertakes no duty or obligation to publicly update or revise the information contained in this report, although it may do so from time to time as its management believes is appropriate. Any such updating may be made through the filing of other reports or documents with the Securities and Exchange Commission (“SEC”), through press releases or through other public disclosure.

Additional Information about the Merger and Where to Find It

In connection with the proposed Merger, the Company intends to file relevant materials with the SEC, including a registration statement on Form S-4 that will contain a prospectus, joint proxy and information statement. Investors and security holders of the Company and Savara are urged to read these materials when they become available because they will contain important information about the Company, Savara and the Merger. The joint proxy statement, information statement, prospectus, and other relevant materials (when they become available), and any other documents filed by the Company with the SEC, may be obtained free of charge at the SEC web site at www.sec.gov. In addition, investors and security holders may obtain free copies of the documents filed with the SEC by the Company by directing a written request to: Mast Therapeutics, Inc., 3611 Valley Centre Drive, Suite 500, San Diego, CA 92130, Attention: Investor Relations. Investors and security holders are urged to read the joint proxy statement, prospectus and the other relevant materials when they become available before making any voting or investment decision with respect to the Merger.

This communication shall not constitute an offer to sell or the solicitation of an offer to sell or the solicitation of an offer to buy any securities, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offering of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended.

Participants in the Solicitation

The Company and its directors and executive officers and Savara and its directors and executive officers may be deemed to be participants in the solicitation of proxies from the stockholders of the Company in connection with the proposed transaction. Information regarding the special interests of these directors and executive officers in the merger will be included in the joint proxy statement/prospectus referred to above. Additional information regarding the directors and executive officers of the Company is also included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 and the proxy statement for the Company’s 2016 Annual Meeting of Stockholders. These documents are available free of charge at the SEC web site (www.sec.gov) and from the Company, Attn: Investor Relations, at the address described above.

Item 9.01 Financial Statements and Exhibits.

Reference is made to the Exhibit Index included with this Current Report on Form 8-K.

About Mast Therapeutics, Inc. (NYSEMKT:MSTX)

Mast Therapeutics, Inc. is a biopharmaceutical company. The Company develops clinical-stage therapies for serious or life-threatening diseases with unmet needs. The Company focuses on developing new therapies for sickle cell disease, a chronic and genetic disorder classified as a rare, or orphan, disease in the United States of America and European Union, and for heart failure, a condition with an unmet need for treatment options. The Company’s segment is engaged in the business of developing therapies for serious or life-threatening diseases. The Company focuses on its Molecular Adhesion and Sealant Technology (MAST) platform, to develop MST-188 (vepoloxamer) Injection, its lead product candidate. The Company also develops AIR001, a sodium nitrite solution for intermittent inhalation through nebulizer. The Company’s AIR001 is in Phase II clinical development for the treatment of patients with HFpEF.

Mast Therapeutics, Inc. (NYSEMKT:MSTX) Recent Trading Information

Mast Therapeutics, Inc. (NYSEMKT:MSTX) closed its last trading session up +0.051 at 0.150 with 99,782,950 shares trading hands.