This multicenter, open-label, single-arm phase 3 study aimed to assess the efficacy and safety of sotatercept in Japanese patients with PAH.
Forty-six adult Japanese patients with pulmonary arterial hypertension receiving stable background therapy were enrolled in a multicenter, open-label, single-arm phase 3 study to assess the efficacy and safety of sotatercept in Japanese patients. They were given subcutaneous sotatercept starting at 0.3 mg/kg, escalating to a target dose of 0.7 mg/kg every 3 weeks. The primary efficacy outcome was the change in pulmonary vascular resistance from baseline to week 24.
Among the 46 patients, 29 (63%) were World Health Organisation (WHO) functional class II and 17 (37%) were class III. By week 24, pulmonary vascular resistance had decreased by 99.2 (95% CI: -129.6 to -68.4) dynes∗sec/cm5, while 6-minute walk distance (the key secondary outcome) increased by 41.8 (95% CI: 27.8-55.5) meters. During the primary treatment period, 6 (13%) serious adverse events occurred, with no treatment discontinuations due to adverse events. The safety profile was consistent with known sotatercept data, with adverse events that were clinically manageable.
Conclusions: This study of Japanese patients with pulmonary arterial hypertension demonstrated improvements in pulmonary vascular resistance and 6-minute walk distance consistent with findings from the pivotal phase 3 STELLAR trial.
Citation
Matsubara H, Tanabe N, Ogo T, Abe K, Inami T, Maeda Y, Arano I, Shirakawa M, Sakai R, Cornell AG; sotatercept study 020 investigators. Phase 3, Open-Label Multicenter Study of Sotatercept in Japanese Participants With Pulmonary Arterial Hypertension. JACC Asia. 2026 Jan 20:S2772-3747(25)00709-4. doi: 10.1016/j.jacasi.2025.12.009. Epub ahead of print. PMID: 41618947.