Mast Therapeutics Announces Positive Interim Results from Phase 2 Trial in Select PH Patients

Mast Therapeutics Inc. announced positive interim results from an ongoing Phase 2a clinical study of its investigational drug AIR001 for the treatment of patients with pulmonary hypertension (PH) associated with heart failure with preserved ejection fraction (HFpEF).

Results were presented by the trial’s lead investigator, Marc A. Simon, MD, MS, FACC, in a poster titled “Efficacy and safety of inhaled sodium nitrite in pulmonary hypertension associated with heart failure with preserved ejection fraction,” at the recent 2016 American Thoracic Society (ATS) International Conference in San Francisco, California.

AIR001 is a sodium nitrite solution for inhalation via nebulization. Nitrite is a vasodilator that can be recycled in vivo to form nitric oxide (NO), producing beneficial effects that include blood vessel dilation and reduced inflammation. In previous clinical studies, the drug has shown potential in reducing right atrial, pulmonary capillary, and pulmonary artery pressure, and in improving cardiac output and exercise tolerance, as measured by the six-minute walk distance test.

The Phase 2a study (NCT01431313) expects to recruit a total of approximately 50 subjects with PH, of which 20 are expected to have a diagnosis of PH associated with HFpEF. Participants will receive a first dose of 45 mg of AIR001 via nebulizer; about 60 minutes after that dose, they will receive one subsequent escalation dose of 90 mg, based on safety and tolerability data. The clinical trial, being conducted at the University of Pittsburgh, is currently recruiting patients.

According to the results of the 10 patients studied to date, AIR001 treatment significantly decreased right atrial, right ventricular systolic and diastolic, pulmonary artery (PA) systolic/diastolic/mean, and pulmonary artery occlusion (PAOP) pressure. Moreover, pulmonary artery occlusion and mean pulmonary artery pressures were markedly decreased when compared to baseline median values, with no significant changes in systemic blood pressure or heart rate.

“These data are consistent with results we saw in a separate Phase 2a study of AIR001 in HFpEF earlier this year and are a further step in validating our second asset and establishing the potential clinical utility of AIR001 in HFpEF,” Brian M. Culley, chief executive officer of Mast Therapeutics, said in a company press release. “We look forward to advancing AIR001 in this area of high unmet medical need for which there is no FDA-approved therapy available.”

AIR001 was also recently selected by the Heart Failure Clinical Research Network for evaluation in a 100-patient, multicenter, randomized, double-blind and placebo-controlled Phase 2 study in patients with HFpEF.

More information on the ongoing clinical trial, including patient eligibility and contact information, is available through this link.

Mast Therapeutics specializes in developing clinical products under its Molecular Adhesion and Sealant Technology (MAST) platform to treat heart disease and sickle cell disease.