Population Health Model Predicting the Long-Term Impact of Sotatercept on Morbidity and Mortality in Patients with Pulmonary Arterial Hypertension (PAH)

Abstract

Introduction: Pulmonary arterial hypertension (PAH) is a rare, progressive disease associated with significant morbidity and mortality. The phase 3 STELLAR trial tested sotatercept plus background therapy (BGT) versus placebo plus BGT. BGT was comprised of mono-, double-, or triple-PAH targeted therapy. Building on STELLAR findings, we employed a population health model to assess the potential long-term clinical impact of sotatercept.

Methods: Based on the well-established ESC/ERS 4-strata risk assessment approach, we developed a six-state Markov-type model (low risk, intermediate-low risk, intermediate-high risk, high risk, lung/heart-lung transplant, and death) to compare the clinical outcomes of sotatercept plus BGT versus BGT alone over a lifetime horizon. State-transition probabilities were obtained from STELLAR. Risk stratum-adjusted mortality and lung/heart-lung transplant probabilities were based on COMPERA PAH registry data, and the post-transplant mortality probability was obtained from existing literature. Model outcomes were discounted at 3% annually. Sensitivity analyses were conducted to examine model robustness.

Results: In the base case, sotatercept plus BGT was associated with longer life expectancy from model baseline (16.5 vs 5.1 years) versus BGT alone, leading to 11.5 years gained per patient. Compared with BGT alone, sotatercept plus BGT was further associated with a gain in infused prostacyclin-free life years per patient, along with 683 PAH hospitalizations and 4 lung/heart-lung transplant avoided per 1000 patients.

Conclusions: According to this model, adding sotatercept to BGT increased life expectancy by roughly threefold among patients with PAH while reducing utilization of infused prostacyclin, PAH hospitalizations, and lung/heart-lung transplants. Real-world data are needed to confirm these findings.

Trial registration: ClinicalTrials.gov identifier, NCT04576988 (STELLAR).

Keywords: Pulmonary arterial hypertension; Risk strata; STELLAR; Sotatercept.

Fig. 1

Model structure

Fig. 2

Base case results, estimated patient distribution by health state. A Short-term distribution: Measured change in STELLAR. B Long-term patient distribution. The patient distribution prior to half-cycle correction is shown above. The majority (around 75% to 80%) of patients receiving sotatercept plus background therapy would experience disease improvement in the first 1–3 years and then remain in the low risk state for the remainder of their lifetime. In contrast, patients receiving background therapy alone were more likely to experience disease progression within the same time frame, with > 80% of the patients remaining in the non-low risk health state afterwards. IH intermediate high; IL intermediate low; trans. transplant