Mast Therapeutics (NYSE:MSTX) touted interim data from a Phase II study of its AIR001 candidate in patients with pulmonary hypertension (PH) and PH associated with heart failure with preserved ejection fraction. Positive interim results from the ongoing trial were published in the Journal of Clinical Investigation.

The San Diego-based company enrolled 50 patients to study its nebulized inhaled nitrite and interim results showed that AIR001 significantly decreased pulmonary, right atrial and pulmonary capillary wedge pressures. The change was most prominent in patients with PH associated with heart failure with preserved ejection fraction.

The treatment was well-tolerated and the researchers did not note any major safety concerns, which satisfied the primary safety outcome of the study. There were also no significant decreases in peripheral oxygen saturation nor increases in methemoglobin levels above 5%, according to the company.

“The results observed to date are important as they demonstrate that AIR001 can significantly lower right atrial pressures, pulmonary artery pressures, and pulmonary artery occlusion pressures, as well as improve pulmonary artery compliance,” chief medical officer Edwin Parsley said in prepared remarks. 

“These data are consistent with results we saw in a separate investigator-sponsored Phase 2 study of AIR001 in HFpEF earlier this year and serve as a further step in validating AIR001 and establishing its potential clinical utility in HFpEF,” CEO Brian Culley added. “We look forward to advancing AIR001 in this area of high unmet medical need for which there is no FDA-approved therapy available. In addition to full results from this 50-patient study, the 100-patient  ‘INDIE-HFpEF’ study of AIR001 also is expected to complete enrollment and announce top-line results next year. We believe these are important value-creating studies which convincingly demonstrate the potential for clinical utility of AIR001 in HFpEF and potentially other settings.”