Merck’s WINREVAIR Significantly Delays Disease Progression In PAH Patients In Phase 3 HYPERION Trial

Merck has announced positive topline results from its Phase 3 HYPERION study evaluating WINREVAIR™ (sotatercept-csrk) for the treatment of pulmonary arterial hypertension (PAH). The study met its primary endpoint, showing a significant delay in time to clinical worsening in recently diagnosed adults with PAH functional class II or III, when WINREVAIR was added to existing background therapy. The composite endpoint included events such as all-cause mortality, unplanned PAH-related hospitalization, lung transplant, atrial septostomy, or disease progression.

“PAH is a progressive and debilitating disease with a poor prognosis that can be difficult to diagnose and treat. Patients often struggle for years to find a treatment plan that helps manage the disease, so it’s critical to provide new options earlier in the treatment journey. The HYPERION study demonstrated that WINREVAIR on top of background therapy met its primary outcome measure of reduction in the time to clinical worsening events in adults who have been recently diagnosed with PAH. WINREVAIR has brought significant optimism to patients, their families and investigators and we thank all study participants for being part of this important study,” said Dr. Vallerie McLaughlin, Kim A Eagle MD Endowed Professor of Cardiovascular Medicine and Director, Pulmonary Hypertension Program, University of Michigan in Ann Arbor. 

WINREVAIR, administered within 12 months of PAH diagnosis and alongside background therapies (most commonly dual therapy), significantly reduced the risk of clinical worsening compared to placebo. HYPERION is Merck’s third successful Phase 3 trial of WINREVAIR, following the STELLAR and ZENITH trials. Unlike previous studies where the majority of patients were on triple therapy, HYPERION focused on those earlier in their treatment journey. The safety profile remained consistent with earlier findings.

“To date, the strong clinical profile of WINREVAIR, a first-in-class activin signaling inhibitor, had been primarily established through previous studies in a prevalent patient population comprised of patients that were several years into their treatment journey. These positive results from HYPERION expand on the body of clinical evidence now including recently diagnosed adults, supporting the practice-changing potential of WINREVAIR in a broad spectrum of PAH patients, including those earlier in their treatment journey. We look forward to presenting these data to the scientific community at a future medical meeting," said Dr. Joerg Koglin, senior vice president, head of general and specialty medicine, global clinical development, Merck Research Laboratories. 

Following the early termination of HYPERION due to overwhelmingly positive interim results from the ZENITH trial, all participants were offered access to WINREVAIR through the SOTERIA open-label extension. WINREVAIR has already received regulatory approval in more than 45 countries based on the STELLAR data. Merck plans to present full HYPERION findings at a medical conference later this year and submit them to regulators for potential label expansion.