Arena Pharmaceuticals Reports Positive Phase 2 Results for PAH Drug

Arena Pharmaceuticals, announced positive Phase 2 results for ralinepag, an investigational, long-acting, orally administered prostacyclin receptor agonist under development for the treatment of pulmonary arterial hypertension (PAH). In this 61-patient study, the primary efficacy analysis demonstrated a statistically significant absolute change from baseline in pulmonary vascular resistance (PVR) compared to placebo. Ralinepag also demonstrated numerical improvement in 6-minute walk distance (6MWD).

Ralinepag improved median PVR by 163.9 dyn.s.cm^-5 from baseline compared to a 0.7 dyn.s.cm^-5 worsening from baseline in the placebo arm (P=0.02). Patients treated with ralinepag had a 29.8% improvement in PVR compared to the placebo arm (P=0.03) and a 20.1% improvement in PVR compared to baseline. Additionally, adverse events observed in the study were consistent with other prostacyclin treatments for the management of PAH, with headache, nausea, diarrhea, jaw pain and flushing being the most commonly reported adverse events. The company plans to present full study results at future medical congresses.

“The positive outcome of this Phase 2 trial in a contemporary PAH patient population is an important milestone in the development of ralinepag for the treatment of patients suffering from this grievous illness,” stated Preston Klassen, M.D., MHS, Executive Vice President, Research and Development and Chief Medical Officer of Arena. “It is exciting to see the positive nonclinical pharmacological profile translating into potentially the first oral prostacyclin therapy that may approach consistent therapeutic levels without the complexity of parenteral (IV) therapy. These data give us confidence to move expeditiously toward a Phase 3 clinical program.”

Vallerie McLaughlin, M.D., Kim A. Eagle MD Endowed Professor of Cardiovascular Medicine at the University of Michiganand Director of the Pulmonary Hypertension Program, added, “PAH is a complex and serious disease, often with a poor prognosis despite the use of currently available treatments. New therapeutic options to manage patients with PAH are needed. The results of this Phase 2 study of ralinepag, in patients already receiving, in most cases, multiple background therapies, showed a clinically meaningful improvement in PVR, a well-established indicator of treatment benefit, believed to be correlated with long-term clinical outcomes in patients with PAH.”