INTERIM findings from the open-label international SOTERIA study suggest that sotatercept, a novel therapy given as an add-on to standard treatment for pulmonary arterial hypertension (PAH), continues to demonstrate long-term safety and effectiveness.
The trial enrolled 426 adults with PAH who had completed earlier sotatercept studies without early discontinuation. All participants were already receiving stable background therapies for their condition and received subcutaneous sotatercept injections once every 21 days. The median duration of treatment was approximately 15 months.
Results from the trial show that 90.8% of participants experienced some form of adverse event (AE), with 3.5% discontinuing treatment due to AEs. Serious adverse events occurred in 30.3% of participants, with 2.6% deemed treatment-related. There were 12 deaths reported, but investigators judged these were not caused by sotatercept in most cases. The most commonly reported side effects of interest included nosebleeds (22.1%) and small dilated blood vessels near the skin known as telangiectasia (16.9%). A small number of participants (5.2%) experienced serious bleeding events, including two fatal cases.
Despite these risks, the study found that the clinical improvements seen in earlier sotatercept trials were largely sustained over 1 year. This included gains in 6-minute walk distance, reductions in NT-proBNP (a marker of heart strain), improvements in WHO functional class, and favourable changes in the simplified French risk score, a tool used to evaluate disease severity and predict outcomes in PAH. These benefits were seen both in patients originally assigned to sotatercept and in those who crossed over from placebo.
While the final safety and efficacy profile of sotatercept will require further follow-up, these interim results support its potential as a long-term treatment option for adults living with PAH. Continued monitoring of the SOTERIA cohort will help clarify sotatercept’s benefit–risk balance in real-world clinical settings.
Reference
Preston IR et al. A long-term follow-up study of sotatercept for treatment of pulmonary arterial hypertension: interim results of SOTERIA. Eur Respir J. 2025;66(1):2401435.
