Merck Announces New Clinical Evidence for Sotatercept, a Potential First-in-Class Therapy Acquired for $11.5 Billion

▎Edited by the WuXi AppTec content team

Today, MSD announced the latest clinical trial results of its potential "first-in-class" therapy, sotatercept. An exploratory post-hoc analysis of the Phase 3 clinical trial STELLAR data showed,Sotatercept Can Reduce the Size of the Right Side of the Heart, Improve Right Ventricular Function and Hemodynamic Parameters in Patients with Pulmonary Arterial Hypertension (PAH) After 24 Weeks of Treatment.The new drug application for Sotatercept is currently under review by the U.S. FDA.

Pulmonary hypertension is caused by an imbalance between pro-proliferative and anti-proliferative signals, leading to thickening of the pulmonary artery walls, restricting blood flow, increasing the burden on the right side of the heart, and eventually resulting in heart failure.

Sotatercept is the key investigational therapy that MSD acquired through the approximately $11.5 billion acquisition of Acceleron Pharma.It is a potential “first-in-class” type IIA activin receptor (ActRIIA) fusion protein. It fuses the modified extracellular domain of ActRIIA with the Fc portion of an antibody. It can block the binding of activin to receptors on the cell membrane, thereby reducing activin-mediated signaling.In preclinical experiments, it can reverse the remodeling of pulmonary artery walls and the right ventricle. It has received Breakthrough Therapy Designation from the FDA, which is alsoThe First Pulmonary Arterial Hypertension Investigational Therapy Granted Breakthrough Therapy DesignationMSD pointed out that it has the potential to become a cornerstone therapy for the treatment of pulmonary arterial hypertension.

▲Sotatercept restores the balance between pro-proliferative and anti-proliferative signaling (Image source: MSD official website)

Previously, Merck & Co., Inc. (MSD) announced that sotatercept met the primary endpoint in the Phase 3 clinical trial STELLAR. Compared with placebo, it brought a statistically significant and clinically meaningful improvement in patients' 6-minute walk distance (6MWD).

The results of this exploratory analysis showed that, on the basis of background treatment, compared with placebo, sotatercept treatment led to improvements from baseline in multiple indicators, including mean pulmonary artery (PA) pressure (-13.9 mmHg), pulmonary vascular resistance (-254.8 dyn·s·cm-5), mean right atrial pressure (-2.7 mmHg), and mixed venous oxygen saturation (3.84%). The press release noted that although this was an exploratory data analysis,They provide clinical evidence for the first time, showing that sotatercept can positively impact parameters of right heart function and size.。