Ziltivekimab in heart failure with preserved and mildly reduced ejection fraction: rationale and design of the ATHENA and HERMES trials

Background Cardiovascular inflammation is thought to play a central role in the pathogenesis of heart failure (HF) with preserved ejection fraction (HFpEF) and heart failure with mildly reduced ejection fraction (HFmrEF), but no therapies specifically targeting inflammation in this setting are currently available. Purpose Here we describe the rationale and design of two clinical trials (ATHENA and HERMES) investigating ziltivekimab, a human monoclonal antibody directed against the IL-6 ligand, in patients with HFpEF/HFmrEF and cardiovascular inflammation. Methods ATHENA and HERMES are international, multicenter, double-blind, placebo-controlled trials randomizing adults with HFpEF/HFmrEF and cardiovascular inflammation to ziltivekimab 15 mg or placebo, both administered subcutaneously once-monthly on top of standard of care. Eligible participants have a left ventricular ejection fraction >40%, elevated NTproBNP and serum high sensitivity C reactive protein ≥2 mg/L. The primary endpoint in ATHENA (n=680) is the change in Kansas City Cardiomyopathy Questionnaire–Clinical Summary Score at 12 months. The primary endpoint in HERMES (n=4900) is the composite of CV death, hospitalization for HF or urgent HF visit. The study is event-driven and will target 845 primary events (Figure 1). Conclusions ATHENA and HERMES will investigate the effect of ziltivekimab in HFpEF/HFmrEF and cardiovascular inflammation. ATHENA will determine the effect of ziltivekimab on health status. HERMES will determine the efficacy and safety of ziltivekimab on morbidity and mortality.