Aires’ lead product candidate, AIR001, is an intermittently nebulized formulation of nitrite that has orphan drug designation in the US and European Union for the treatment of pulmonary arterial hypertension.
Mast Therapeutics CEO Brian M Culley noted the addition of AIR001 provides the company with not only an exciting Phase II asset in the area of pulmonary disease, but also an ideal complement to its lead product, MST-188.
"With MST-188 in an ongoing pivotal trial for sickle cell disease and a phase 2 trial expected to initiate this quarter in acute limb ischemia, the addition of another phase 2-ready asset further enhances our pipeline, providing us with diversity across specialized indications as well as cohesion in addressing significant unmet medical needs.
"In addition, as previously reported, although our estimated costs for AIR001 will change as we refine our development strategy over the next few months, we currently anticipate that our first year of development of AIR001 will be covered by Aires’ net cash at closing of $2.6 million," Culley added.
Under the terms of the all-stock transaction, which was completed on 27 February 2014, Aires became a wholly-owned subsidiary of Mast Therapeutics in exchange for a total of 5.2 million shares of Mast common stock, representing approximately 5% of Mast’s outstanding common stock.
Approximately 80% of the shares comprising the merger consideration are being held back for a period of six months to satisfy any indemnification obligations of the former Aires’ stockholders under the merger agreement. There are no milestone obligations payable by Mast.
AIR001 (sodium nitrite) inhalation solution, also known as Aironite, is an intermittently nebulized formulation of nitrite, which can be converted to nitric oxide independent of nitric oxide synthase activity.
Nitrite mediated nitric oxide formation has several beneficial effects, including dilation of blood vessels and reduction of inflammation and undesirable cell growth. AIR001 has been granted orphan drug designation by the US Food and Drug Administration and the European Commission for the treatment of pulmonary arterial hypertension.