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

We hypothesized that targeting interleukin-6—a cytokine central to NOD-like receptor protein 3 (NLRP3) inflammasome activation that is associated with both the onset and progression of heart failure (HF)—may be beneficial in patients with HF and circulating evidence of cardiovascular inflammation but without overtly reduced ejection fraction (EF). We describe the rationale and design of two clinical trials (ATHENA and HERMES) investigating ziltivekimab, a human monoclonal antibody directed against the interleukin-6 ligand, in patients with HF and mildly reduced or preserved EF (HFmrEF/HFpEF) and cardiovascular inflammation.

ATHENA (n = 673) and HERMES (n = 4900) are international, multi-centre, double-blind, placebo-controlled trials randomizing adults with HFpEF/HFmrEF and cardiovascular inflammation (high-sensitivity C-reactive protein ≥2 mg/l) to ziltivekimab 15 mg or placebo, administered subcutaneously once monthly on top of standard of care. Eligible participants have a left ventricular EF >40%, elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP), and serum high-sensitivity C-reactive protein ≥2 mg/l. The primary endpoint in ATHENA is the change in Kansas City Cardiomyopathy Questionnaire—Clinical Summary Score at 12 months. The primary endpoint in HERMES is time to first composite of cardiovascular death, hospitalization for HF, or urgent HF visit. ATHENA has a fixed duration of 12 months, whereas the HERMES trial is event driven (∼845 adjudicated primary events) with a minimum exposure of 6 months from randomization to the last treatment visit.

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.