A Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase 2 Study Evaluating the Safety and Efficacy of Different Doses of IW-1973 over 12 Weeks in Patients with Heart Failure with Preserved Ejection Fraction


The objective of the CAPACITY-HFpEF study is to evaluate the safety and efficacy of IW-1973 compared with placebo when administered daily for approximately 12 weeks to patients with HFpEF. The study will evaluate the effect of oral IW-1973 on peak exercise capacity in patients with HFpEF, with or without permanent or persistent atrial fibrillation.


  • Patient is an ambulatory male or female ≥45 years old at the Screening Visit
  • Patient has heart failure with ejection fraction (EF) of ≥40%
  • Patient has a peak VO2 measuring <80% of age- and sex-adjusted normal values
  • Patient has evidence in medical history supporting clinical heart failure syndrome
  • Patient meets at least 2 of the following criteria at the Screening Visit:
    1. Diagnosis of type 2 diabetes mellitus or prediabetes
    2. History of hypertension
    3. Body mass index (BMI) >30 kg/m2
    4. Age ≥70 years