Arena Pharmaceuticals completed patient enrollment in its Phase 2 clinical trial evaluating ralinepag (APD811) for the treatment of pulmonary arterial hypertension (PAH).
The clinical trial (NCT02279160) first began dosing patients in January 2015 and enrolled a total of 60 patients at sites in the U.S, Australia, Spain, and countries in eastern Europe.
The study is a randomized, double-blind, placebo-controlled assessment of the effectiveness of ralinepag in reducing pulmonary vascular resistance (PVR) and improving exercise capacity in PAH patients at 22 weeks.
The trial’s primary endpoints are the change from baseline in PVR and improvements of exercise capacity as assessed by a change from baseline in the six-minute walk distance test (6MWD).
Ralinepag is an investigational drug discovered and developed by Arena to treat vascular diseases, including PAH. The drug is an oral agonist of the IP receptor targeting the prostacyclin pathway.
According to Arena, in Phase 1 clinical trials, ralinepag showed an approximate 25-hour half-life, suggesting the compound could be dosed once or twice daily.
After completing the 22 weeks of the Phase 2 trial, study participants with Group 1 PAH, as defined by the World Health Organization (WHO), become eligible to enroll in the long-term open-label trial (NCT02279745) to evaluate the safety and tolerability of ralinepag.
The U.S. Food and Drug Administration (FDA) granted Orphan Drug status to ralinepag for the treatment of PAH in September 2014.
“This marks an important step in the development of ralinepag and is evidence of our strategic focus on our pipeline,” Amit Munshi, president and CEO of Arena Pharmaceuticals, 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.”
PAH is characterized by an increase of blood pressure in the pulmonary artery, vein or capillaries – together known as the lung vasculature. The pulmonary artery carries blood from the heart (right ventricle) to the lungs.
When the lung vasculature becomes narrower in diameter, this increases resistance to blood flow through the vessels, increasing the pressure inside the vessels as well as on the right ventricle. This forces the right ventricle to pump harder to move blood into the pulmonary artery, causing the heart to become enlarged and weakened. This can ultimately lead to heart failure.