Opsumit Has Potential to Improve Right Ventricle Function in PAH Patients, Phase 4 Data Show

Alice Melão, MSc avatar

by Alice Melão, MSc |

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Treatment with Opsumit (macitentan) can significantly improve the heart’s right ventricular function, reverse cardiac tissue remodeling, and reduce pulmonary vascular resistance (PVR) in patients with pulmonary arterial hypertension (PAH), preliminary results from a Phase 4 clinical trial show.

The most recent data from the Phase 4 REPAIR trial (NCT02310672) were discussed at the 68th Annual Scientific Session of the American College of Cardiology, in an oral presentation titled “Effects of Macitentan on Right Ventricular Remodeling in Pulmonary Arterial Hypertension: Results From the REPAIR Study Interim Analysis.”

The open-label trial was designed to assess the impact of Opsumit over a 52-week period on cardiac function, in particular on right ventricular (RV) remodeling and activity, in approximately 89 PAH patients at more than 40 sites worldwide.

Researchers are using cardiac magnetic resonance imaging (MRI) and right heart catheterization to evaluate the effects of the treatment. According to the company, this trial is the first to use a primary objective measured by MRI to assess RV changes in PAH.

“The REPAIR study methodology represents a novel approach to clinical assessment, and the impact of the effects of macitentan on RV remodeling and function in patients with pulmonary arterial hypertension,” Richard N. Channick, MD, professor of medicine and director of the Acute and Chronic Thromboembolic Disease Program at UCLA Medical Center, said to Pulmonary Hypertension News.

During the trial, participants are receiving treatment with Opsumit alone or in combination with a phosphodiesterase-type 5 (PDE-5) inhibitor to help dilate blood vessels and reduce blood pressure.

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A preliminary analysis of the first 42 PAH patients (mean age of 46.3 years) included in the trial, after 26 weeks of treatment with Opsumit, showed that right ventricular systolic pressure (RVSV) increased by 16.6 milliliters compared with before the treatment. These patients also had a significant reduction in PVR of about 37%.

These interim data showed that treatment with Opsumit can help to improve RV function in patients with PAH.

“Measurement of RV function in patients with PAH is very helpful in monitoring response to treatment,” Channick said in a press release.

“These interim results offer important new evidence to inform clinicians’ ability to treat this severe and progressive disease,” he told PH News.

The REPAIR trial is no longer recruiting, but will continue to assess the effects of Opsumit in all enrolled patients until completion of the 52 weeks of treatment and follow-up.

To date, the safety profile of Opsumit in the REPAIR study has been similar to that reported in previous studies, with no new safety issues reported.

“We are very pleased with these interim results from the REPAIR study, and we will work diligently to report the full study results in the near future,” said Alessandro Maresta, MD, vice president and head of global medical affairs at Actelion Pharmaceuticals, Opsumit’s developer. “We are committed to ongoing research and to advancing therapies for people with PAH and are proud to make a difference in patients’ lives.”

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