Myeloperoxidase Inhibition in Heart Failure With Preserved or Mildly Reduced Ejection Fraction:SATELLITE Trial Results

BACKGROUND: Inflammation is a key driver of heart failure (HF) with preserved left ventricular ejection fraction (LVEF). AZD4831 inhibits extracellular myeloperoxidase, reduces inflammation and improves microvascular function in preclinical disease models. METHODS: In this double-blind phase 2a study (SATELLITE; NCT03756285), patients with symptomatic HF, LVEF ≥40%, and elevated B-type natriuretic peptides were randomized 2:1 to once-daily oral AZD4831 5 mg or placebo for 90 days. We aimed to assess target engagement (primary endpoint: myeloperoxidase specific activity) and safety of AZD4831. RESULTS: Due to COVID-19, the study was terminated early after randomizing 41 patients (median age, 74.0 years; 53.7% male). Myeloperoxidase activity was reduced by >50% from baseline to day 30 and 90 in the AZD4831 group, with a placebo-adjusted reduction of 75% (95% confidence interval: 48, 88; nominal P <0.001). No improvements were noted in secondary/exploratory endpoints, apart from a trend in Kansas City Cardiomyopathy Questionnaire overall summary score. No deaths or treatment-related serious adverse events occurred. AZD4831 treatment-related adverse events were generalized maculopapular rash, pruritus and diarrhoea (all n=1). CONCLUSIONS: AZD4831 inhibited myeloperoxidase and was well tolerated in patients with HF and LVEF ≥40%. Efficacy findings were exploratory due to early termination but warrant further clinical investigation of AZD4831. LAY SUMMARY: Few treatments are available for patients with the forms of heart failure known as 'heart failure with preserved or mildly reduced ejection fraction'. Current treatments do not target inflammation, which may play an important role in this condition. We tested a new drug called AZD4831 (mitiperstat), which reduces inflammation by inhibiting the enzyme myeloperoxidase. Among the 41 patients in our clinical trial, AZD4831 had a good safety profile and inhibited myeloperoxidase by the expected amount. Results mean we can conduct further trials to see whether ...