Actelion has announced data evaluating initial combination therapy with Opsumit® (macitentan) and tadalafil, a PDE-5 inhibitor.
Patients with pulmonary arterial hypertension (PAH, WHO Classification Group 1) taking this combination showed haemodynamic improvement, as well as improvements in functional parameters and risk profiles. The combination was also well tolerated in these patients.
The study data were shared at the CHEST Annual Meeting 2019 held 19-23 October in New Orleans, Louisiana.
The OPTIMA (cOmbination theraPy of maciTentan and tadalafIl in patients with newly diagnosed pulMonary Arterial Hypertension) study was a prospective, multicentre, single-arm, open-label, Phase IV trial evaluating the efficacy, safety, and tolerability of initial oral combination therapy with macitentan and tadalafil in patients with newly diagnosed PAH. A total of 46 patients were enrolled in the study.
“Macitentan, in combination with tadalafil, showed a 47% reduction of the primary endpoint of mean pulmonary vascular resistance (PVR) at week 16 compared with baseline in patients with PAH,” said Olivier Sitbon, MD, PhD, principal investigator and professor of respiratory medicine at Université Paris-Sud. “These data are meaningful because improvement of PVR, an important indicator of right ventricular function, is a key treatment goal. Current clinical guidelines for PAH recommend upfront double oral combination therapy and this study confirms that initial oral dual combination with macitentan and tadalafil is beneficial in those patients.”
Safety and tolerability findings were consistent with previous clinical trials that supported the approval and use of macitentan 10mg once-daily. The most common adverse events (AEs) in the OPTIMA study were peripheral oedema (28.3%), headache (23.9%), diarrhoea (19.6%), dyspnoea (15.2%), anaemia (13.0%) and asthenia (13.0%). Four patients had a decrease in haemoglobin below 10g/dl and one patient had aminotransferases ≥3 times the upper limit of normal. Three patients discontinued treatment due to AEs and three patients died during the study. Causes of death were cardiac arrest, heart failure, and multiorgan failure with sepsis.
“The results of the OPTIMA study provide valuable insights about the safety and efficacy of macitentan in combination with a PDE-5 inhibitor and add to the body of evidence supporting combination therapy as the standard of care,” said Alessandro Maresta, MD, Vice President and Head of Medical Affairs at Actelion Pharmaceuticals Ltd. “PAH continues to have a devastating impact on people’s lives and our focus is on researching and developing innovative medicines that improve the lives of these patients.”