The Impact of Immunogenicity on the Pharmacokinetics, Efficacy, and Safety of Sotatercept in a Phase III Study of Pulmonary Arterial Hypertension

Population pharmacokinetic modeling of sotatercept in healthy participants and patients with pulmonary arterial hypertension

Sotatercept is a breakthrough, first-in-class biologic, that is FDA-approved for the treatment of pulmonary arterial hypertension (PAH). A population pharmacokinetic (PopPK) model was developed using data from two phase 1 studies in healthy participants, and two phase 2 studies and one phase 3 study in participants with PAH. The pooled sotatercept PK data encompassed single intravenous (IV) or subcutaneous (SC) doses ranging from 0.01 to 3.0 mg/kg, as well as multiple SC doses ranging from 0.03 to 1.0 mg/kg, with PK samples collected up to a maximum of ~150 weeks following Q3W and Q4W dosing regimens. The final PopPK analysis included 350 participants, with 30 and 320 participants receiving sotatercept IV and SC, respectively. A two-compartment model with a first-order absorption rate constant and a linear disposition from central compartment well-described sotatercept PK. The estimated bioavailability is ~66%; bioavailability, clearance (CL), and central volume (VC) have low to moderate inter-individual variability. Time-varying body weight and baseline albumin concentration were statistically significant predictors of PK; CL and VC were predicted to increase with increasing body weight, while CL was predicted to decrease with increasing baseline albumin concentration. However, the magnitude of covariate effects is not predicted to meaningfully alter the disposition of sotatercept. Altogether, the PopPK modeling results demonstrate favorable PK characteristics (low to moderate variability and typical bioavailability), supporting sotatercept as a SC biological agent for the treatment of patients with PAH.

Circulating Biomarkers in Pulmonary Arterial Hypertension: An Update

Pulmonary arterial hypertension (PAH) is a rare subtype of group 1 pulmonary hypertension (PH) diseases, characterized by high pulmonary artery pressure leading to right ventricular dysfunction and potential life-threatening consequences. PAH involves complex mechanisms: vasoconstriction, vascular remodeling, endothelial dysfunction, inflammation, oxidative stress, fibrosis, RV remodeling, cellular hypoxia, metabolic imbalance, and thrombosis. These mechanisms are mediated by several pathways, involving molecules like nitric oxide and prostacyclin. PAH diagnosis requires clinical evaluation and right heart catheterization, confirming a value of mPAP ≥ 20 mmHg at rest and often elevated pulmonary vascular resistance (PVR). Even if an early and accurate diagnosis is crucial, PAH still lacks effective biomarkers to assist in its diagnosis and prognosis. Biomarkers could contribute to arousing clinical suspicion and serve for prognosis prediction, risk stratification, and dynamic monitoring in patients with PAH. The aim of the present review is to report the main novelties on new possible biomarkers for the diagnosis, prognosis, and treatment monitoring of PAH.

Treating Pulmonary Arterial Hypertension With Sotatercept: A Meta-Analysis

Pulmonary arterial hypertension (PAH) results from proliferative remodeling and narrowing of the pulmonary vasculature. Sotatercept is a first-in-class fusion protein that has recently garnered attention for showing improvements in patients with PAH. This meta-analysis of randomized controlled trials (RCTs) assesses the overall efficacy of Sotatercept in treating PAH. PubMed, Google Scholar, and Clinicaltrials.gov were searched using relevant keywords and MeSH terms. Studies were included if RCTs compared Sotatercept with placebo in patients with PAH. Our comprehensive literature search yielded 3,127 results, of which two RCTs with 429 patients were included in this meta-analysis. The patients were on background therapy for PAH. Results of the meta-analysis show that when compared with placebo, Sotatercept improved the six-minute walk distance (mean difference [MD] 34.99; 95% confidence interval [CI] 19.02-50.95; P < 0.0001), the World Health Organization (WHO) functional class (odds ratio [OR] 2.50; 95% CI 1.50-4.15; P = 0.0004), and pulmonary vascular resistance (PVR, MD -253.90; 95% CI -356.05 to -151.75; P < 0.00001). However, reduction in N-terminal pro-B-type natriuretic peptide (NT-proBNP, MD -1563.14; 95% CI -3271.93 to 145.65; P = 0.07) was not statistically significant in the Sotatercept group versus placebo. In conclusion, Sotatercept improves the six-minute walk distance, WHO functional class, and PVR in patients with PAH receiving background therapy. However, the effect on NT-proBNP levels was not statistically significant. More research is needed to assess the clinical relevance of these findings.