Mast Therapeutics Reports Deal for Phase 2 Study of AIR001

Mast Therapeutics, Inc. (NYSE MKT:

), a biopharmaceutical company developing novel, clinical-stage therapies for sickle cell disease and heart failure, today reported that its wholly-owned subsidiary, Aires Pharmaceuticals, Inc., has entered into an agreement with Duke University to provide support for a multicenter, randomized, double-blind, placebo-controlled Phase 2 clinical study of the Company's product candidate AIR001 in patients with heart failure with preserved ejection fraction (HFpEF). This 100-patient study, known as the Inorganic Nitrite Delivery to Improve Exercise Capacity in HFpEF (INDIE-HFpEF) study, will be sponsored by Duke Clinical Research Institute (DCRI) as the Coordinating Center for the Heart Failure Clinical Research Network (HFN) and conducted at premier clinical centers in the United States that are part of the HFN. HFpEF is a common form of heart failure that has not responded as well to previously tested treatments as heart failure with reduced ejection fraction. AIR001, a sodium nitrite solution that is administered by way of intermittent inhalation via nebulization, was obtained by Mast Therapeutics in 2014 through the acquisition of then privately-held Aires Pharmaceuticals. The Company recently reported positive top-line results from a blinded and randomized Phase 2a clinical study of AIR001 in HFpEF patients conducted at Mayo Clinic. The HFN was established by the NHLBI to expedite clinical research on treatments and strategies to improve the management of acute and chronic heart failure. The HFN's work is supported by a grant awarded by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health (NIH). Under the agreement with the HFN Coordinating Center, as previously anticipated, the Company will provide test materials, nebulizers, and regulatory, technical and additional financial support. The Chair of the HFN Executive Committee is Dr. Eugene Braunwald, Distinguished Hersey Professor of Medicine at Harvard Medical School. The collaborative scientific leadership for the study will include Dr. Barry Borlaug, the Principal Investigator, and other investigators from the HFN Regional Coordinating Centers. The HFN Coordinating Center will be led by Dr. Adrian Hernandez and Dr. Kevin Anstrom of the DCRI. "We appreciate the NIH's, NHLBI's, and HFN's recognition of the study of AIR001 in heart failure as an appropriate area of investigation," stated Brian M. Culley, Chief Executive Officer of Mast Therapeutics, Inc. "This study will accelerate efforts to define the potential efficacy of AIR001 for patients who have heart failure with preserved ejection fraction. This is an area of significant unmet need. There are more than 1 million heart failure hospitalizations each year in the U.S., about half are patients with HFpEF, and, currently, there are no proven effective therapeutic agents available for this large patient population." "The investigator initiated Investigational New Drug Application (IND) has been submitted and DCRI anticipates that the study will begin recruiting patients in the third quarter of this year," continued Mr. Culley. "We look forward to supporting DCRI and the HFN on this study."