APD811, an orally available agonist of the prostacyclin (IP) receptor, is an internally discovered investigational drug candidate intended for the treatment of pulmonary arterial hypertension (PAH). In October 2012, we initiated a Phase 1 multiple dose clinical trial to evaluate the safety, tolerability and pharmacokinetics of multiple-ascending doses of APD811 and the optimal titration schedule. We previously evaluated single-ascending doses of APD811 in the initial Phase 1 clinical trial and believe the results suggest that APD811 has the potential for once-daily, oral dosing.

PAH is a progressive, life-threatening disorder characterized by increased pressure in the arteries that carry blood from the heart to the lungs. The increased pressure strains the heart, which can limit physical activity, result in heart failure and reduce life expectancy. Based on data from the Registry to EValuate Early And Long-term PAH disease management (REVEAL) of patients in the United States, there is an estimated five-year survival rate of 57% from diagnosis.

Treatment with IP agonists, which can slow disease progression and improve exercise tolerance in PAH patients, is considered standard of care for advanced PAH. Currently available IP agonists belong to the prostanoid class of molecules, and these products need to be administered frequently or continuously through intravenous, subcutaneous or inhaled delivery methods. We believe that an orally available, non-prostanoid IP agonist that provides clinical benefits similar to currently available IP agonists has the potential to improve the standard of care for PAH.

APD811 has not been approved by the US Food and Drug Administration or any other regulatory agency.