A37-05 An Early View of Real-World Characteristics of Patients on Sotatercept in the United States: A Focus on Comorbidities

Rationale Sotatercept, a first-in-class activin signaling inhibitor, was approved in the United States in March 2024 for the treatment of pulmonary arterial hypertension (PAH). Evidence describing the real-world patient characteristics of patients prescribed sotatercept is limited. This crosssectional analysis provides an early understanding of patient characteristics of sotatercept initiators and a contemporaneous PAH cohort not treated with sotatercept. Methods This retrospective cohort study used the Komodo Research Data claims database from 10/01/2023-11/30/2024. The sotatercept cohort included adults with ≥1 sotatercept prescription on or after March 26, 2024, and ≥6 months of prior continuous enrollment. The index date was the first sotatercept claim. The non-sotatercept cohort included adults with PAH, identified using diagnostic criteria and claims for PAH-targeted therapy, who had no sotatercept exposure and at least 6 months of continuous enrollment before a randomly-assigned index date. Baseline characteristics, including the Quan-Charlson Comorbidity Index (QCI) and select comorbid conditions, were measured during the 6 months pre-index. Two-sample comparisons were conducted using Chi-squared and Fisher’s exact tests. Results Among 3,865 patients (315 sotatercept and 3,550 non-sotatercept), sotatercept initiators were younger (median age of 59 vs 63 years), more often female (79% vs 59%), and had, on average, a greater comorbidity burden (QCI 2.9 vs 2.4). The three most common comorbidities were cardiovascular in nature, with similar frequencies in both cohorts: heart failure (sotatercept 64% vs non-sotatercept 40%); hypertension (52% vs 57%); hyperlipidemia (37% vs 43%). Chronic pulmonary disease (35% in both cohorts) and sleep apnea (43% vs 31%) were also common pulmonary/breathing-related conditions in both cohorts. No meaningful difference was observed in the proportion of patients with connective tissue disease (17% vs 16%). Both the proportion of patients overweight/obese (25% vs 29%) and the proportion underweight (<1% in both cohorts) was found to be similar (see Figure 1). Regarding concomitant therapy, a higher proportion of patients initiating sotatercept had evidence of prior diuretics use (80% vs 58%), while prior antithrombotic (27% vs 29%) and anticoagulant (23% vs 25%) use was similar. Conclusions In the initial months post-approval, sotatercept was primarily initiated in patients who were younger and more often female compared to the general PAH patient population in this analysis. Baseline comorbidity burden was similar among sotatercept users and nonusers, indicating no detectable differential effect of comorbid conditions on sotatercept prescribing in this early-view data.