– Study reproduced earlier findings that a single, 2-hour intravenous administration of vepoloxamer resulted in robust improvements in key parameters of heart function that persisted for up to 2 weeks
– New findings demonstrated that retreatment at 3 weeks resulted in improvements in ventricular function similar to the first administration and that the treatment effect was sustained for at least 3 additional weeks (to end of 6-week study)

SAN DIEGO, CA, USA I March 2, 2015 I Mast Therapeutics, Inc. (NYSE MKT: MSTX), a clinical-stage biopharmaceutical company, today announced preliminary findings from a randomized, placebo-controlled, nonclinical study of vepoloxamer (MST-188) in a model of chronic, stable heart failure produced by intracoronary microembolizations.  The primary objective of this study was to examine the effects of repeat intravenous administration of vepoloxamer on left ventricular (LV) systolic and diastolic function.

Consistent with results of a previously reported study, in this study, a single, two-hour administration of vepoloxamer resulted in robust improvements that persisted for 1 – 2 weeks in key parameters of heart function, including LV end-systolic volume, ejection fraction, stroke volume, and cardiac output. Notably, LV ejection fraction was improved by approximately 20% for up to two weeks, returning to baseline values by three weeks post-administration.  Diastolic function also was improved.  Following a second administration (three weeks after the first), similar improvements in LV systolic and diastolic function were again observed.  The effects observed after the second administration persisted for at least three weeks post-administration to the end of the six-week study.  Notably, after the second administration, LV ejection fraction had not returned to baseline values by the end of the six-week study, but was still improved by approximately 20% above baseline.  Vepoloxamer had no statistically significant effect on heart rate or blood pressure compared to control. 

Dr. Hani N. Sabbah, Professor of Medicine & Director of Cardiovascular Research at Henry Ford Health System, said: “The membrane-sealing activity of vepoloxamer may be helping restore damaged cardiac cell membrane integrity, thus minimizing calcium overload injury, preserving cardiomyocytes, and directly improving LV contractile function.  These results support clinical testing of pulsed therapy with vepoloxamer in patients with chronic heart failure as well as acute administration in acute heart failure.  Therapy with vepoloxamer may be particularly useful in treating heart failure patients after discharge from the hospital following an acute heart failure exacerbation event.”

Dr. R. Martin Emanuele, the Company’s Senior Vice President, Development, said: “Because vepoloxamer is administered by intravenous injection, we initially believed the clinical utility would be limited to acute heart failure.  However, these new findings are supportive of use in chronic heart failure and, in particular, during the period following hospital discharge, which is considered a ‘high vulnerability’ period for chronic heart failure patients as it is associated with high re-hospitalization and mortality rates, or in patients with continued myocardial injury as evidenced by biomarker testing.  In addition, the dose that was used in these nonclinical studies is approximately one-third of the dose that is administered in our ongoing Phase 3 study in sickle cell crisis.  Accordingly, we believe this dose will translate well to future clinical studies conducted in heart failure patients.”

About Heart Failure
Heart failure is a chronic, progressive condition in which heart muscle is unable to pump sufficient blood to meet the body’s needs.  It is estimated that more than 20 million individuals worldwide, including five to six million in the U.S., suffer from heart failure, which is the most common diagnosis for hospital admission in the U.S. for patients over age 65.  The American Heart Association estimates that total medical costs of heart failure in the U.S. will increase from approximately $21 billion in 2012 to approximately $53 billion in 2030, with the majority (80%) of such costs related to hospitalization. 

About Vepoloxamer
Vepoloxamer is the unique non-proprietary (generic) name for purified poloxamer 188.  The Company sought a unique name to clearly identify its purified poloxamer 188 as different from non-purified poloxamers.  In support of its application for vepoloxamer to the United States Adopted Names (USAN) Council, the Company submitted proprietary data showing that drug products containing non-purified poloxamers may have serious toxicity consequences and should not be substituted for or confused with drug products containing vepoloxamer.

About Mast Therapeutics
Mast Therapeutics, Inc. is a publicly traded biopharmaceutical company headquartered in San Diego, California.  The Company is leveraging the MAST (Molecular Adhesion and Sealant Technology) platform, derived from over two decades of clinical, nonclinical and manufacturing experience with purified and non-purified poloxamers, to develop vepoloxamer (MST-188), its lead product candidate, for serious or life-threatening diseases and conditions typically characterized by impaired microvascular blood flow and damaged cell membranes. 

The Company is enrolling subjects into EPIC, a pivotal Phase 3 study of vepoloxamer in sickle cell disease, and into a Phase 2 study to evaluate whether vepoloxamer improves the effectiveness of recombinant tissue plasminogen activator therapy in patients with acute limb ischemia.  The Company also is planning to initiate a Phase 2 study of vepoloxamer in patients with heart failure this year. More information can be found on the Company’s web site at www.masttherapeutics.com. (Twitter: @MastThera).

SOURCE: Mast Therapeutics