Arena Pharmaceuticals has announced results from a Phase I clinical trial of an orally bioavailable agonist of the prostacyclin receptor, APD811, as a treatment for pulmonary arterial hypertension.

The randomised, double-blind and placebo-controlled trial enrolled 32 healthy volunteers in four cohorts of eight participants each. The drug showed dose-proportional pharmacokinetic exposure over the tested dose range.

Arena senior vice-president and chief medical officer William Shanahan said that the encouraging results of the study will make the company further evaluate the safety, tolerability and pharmacokinetics of multiple dosing and the optimal titration schedule in a Phase Ib trial.