Arena Completes Enrollment of PAH Patients in Ralinepag Phase 2 Study

Arena Pharmaceuticals has completed enrolling patients with pulmonary arterial hypertension (PAH) in its Phase 2 clinical trial evaluating the effectiveness of ralinepag (APD811), the company’s investigational drug for the treatment of PAH.

“This marks an important step in the development of ralinepag and is evidence of our strategic focus on our pipeline,” Amit Munshi, Arena’s president and CEO, said in a press release. “We believe ralinepag has the potential to achieve a best-in-class profile for patients suffering from PAH and we look forward to seeing the results mid-year to confirm our hypothesis.”

The 22-week placebo-controlled Phase 2 trial (NCT02279160) enrolled 60 patients with PAH at clinical sites globally to evaluate the effectiveness, safety and tolerability of ralinepag.

The study’s primary endpoints include the change from baseline in pulmonary vascular resistance (PVR), and the improvements of exercise capacity as assessed by a change from baseline in the six-minute walk distance (6MWD) test. Both endpoints will be measured after 22 weeks of treatment.

Arena will then assess the long-term safety and tolerability of ralinepag in patients with WHO Group 1 PAH who have completed the Phase 2 study. Patients enrolled in this open-label study (NCT02279745) must have completed the Phase 2 study and must meet specific eligibility criteria.

Ralinepag is an oral, selective IP receptor agonist targeting the prostacyclin pathway that is in development for the treatment of vasospastic diseases such as PAH. The drug combines potent actions on pulmonary vascular smooth muscle cells and platelets with an optimized pharmacokinetic profile.

In Phase 1 studies, ralinepag showed an approximate 25-hour half-life, indicating that it could be dosed either once or twice daily. Arena believes the drug’s high intrinsic potency and activity at the human IP receptor could potentially improve treatment for patients with PAH.

In September 2014, the U.S. Food and Drug Administration (FDA) granted ralinepag Orphan Drug designation for the treatment of PAH.

PAH is a medical condition characterized by an increase of blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, leg swelling and other symptoms. Therapies are greatly needed to help patients manage their symptoms, as PAH is a life-threatening disease.