Mast Therapeutics Inc. reported top-line results from a Phase 2 study of AIR001 (sodium nitrite) inhalation solution for the treatment of pulmonary arterial hypertension (PAH). Mast obtained the rights to the AIR001 program through its acquisition of privately-held Aires Pharmaceuticals Inc. earlier this year. In the primary efficacy analysis of the Phase 2 study, all doses showed improvement in median pulmonary vascular resistance (PVR). In the secondary efficacy analysis, all doses showed improvements in the median distances obtained in the six-minute walk test, including clinically-meaningful improvements at the highest dose level. Additionally, AIR001 was well-tolerated, with no treatment related serious adverse events. In particular, methemoglobin levels remained normal (< 1.5%), which distinguishes AIR001 from safety concerns associated with intravenously-administered nitrite. 

 

Edwin Parsley, interim chief medical officer, stated: “These results are promising and consistent with earlier findings of AIR001 as an agent that can have a positive effect on hemodynamic parameters in a PH population. To date, more than 120 individuals have received AIR001, including patients who have received repeat administration for as long as 12 months, patients who were treatment naive, and patients on PAH disease-specific background therapy. Given the hemodynamic improvements observed, we feel AIR001 may be uniquely suited to address the serious unmet need facing the large number of patients with pulmonary hypertension associated with left heart disease. Consequently, we will be pursuing clinical development of AIR001 in that indication and plan to support multiple, institution-sponsored Phase 2a studies that will evaluate 1) acute hemodynamic effects, 2) acute effects versus placebo on maximum oxygen consumption and exercise hemodynamics, and 3) inhaled versus intravenous administration of nitrite, as well as the safety of multiple doses of AIR001, in patients with PH associated with left heart disease.”

 

Brian Culley, chief executive officer, stated: “We are encouraged by the results seen in the Phase 2 study of AIR001 and believe they further validate our acquisition of Aires. The data from the study show benefits consistent with prior studies and support further development of AIR001. We look forward to proceeding with the Phase 2a studies in PH associated with left heart disease and anticipate reporting preliminary study results as early as the second half of 2015.”

 

Date: September 8, 2014

Source: Mast Therapeutics