Actelion Pharmaceuticals Ltd. has announced the results of the first randomized controlled trial in portopulmonary hypertension (PoPH), which showed that macitentan (Opsumit®) significantly improved pulmonary vascular resistance (PVR) compared with a placebo. Macitentan is currently approved for the treatment of pulmonary arterial hypertension (PAH). Presented as a late-breaking oral presentation at the European Respiratory Society meeting in France by lead investigator, Olivier Sitbon, M.D., Ph.D., professor of respiratory medicine at Université Paris-Sud, macitentan as a treatment for PoPH was shown to be similarly safe to previous clinical trials of the drug.
The PORTICO study (PORtopulmonary Hypertension Treatment wIth maCitentan – a randOmized Clinical Trial), sponsored by Actelion, is a clinical trial to assess the safety and efficacy of macitentan in people with PoPH at 52 pulmonary hypertension (PH) programs around the world. Eighty-five patients have participated in the clinical trial.
PoPH is a specific type of World Health Organization (WHO) Group 1 PH (pulmonary arterial hypertension, or PAH) that is associated with high blood pressure in the liver (portal hypertension). Underlying chronic liver disease does not always cause this high blood pressure; however, PoPH is frequently caused by cirrhosis. In many cases, patients with PoPH diagnosed as part of an assessment for liver transplantation; however, patients with severe PAH are unable to receive a liver transplant due to the worse outcomes compared to patients without PAH.
After three months of treatment, participants in the clinical trial taking macitentan had lower pulmonary vascular resistance, lower mean pulmonary artery pressure and improved cardiac index compared to participants taking a placebo. The scientists did not find a difference in the six-minute walk distance or WHO Functional Classification when comparing participants taking macitentan to those taking a placebo.
According to Dr. Sitbon, the findings of PORTICO are relevant because if patients with PoPH can be treated to successfully lower pulmonary vascular pressure and resistance, more patients may be eligible for liver transplant as they will potentially have a better prognosis for this surgery.