Phase Ib/IIa Trial With AC01 in Patients With HFrEF

Key Inclusion Criteria, Dose Escalation Phase: * Male and female out-patients of any ethnicity, between 18-80 years (inclusive), with stable HFrEF. * Chronic HF for at least 6 months duration defined by history with current NYHA class II-III severity. * LVEF ≤40% by TTE more than 6 months before screening and again at screening (screening measurement confirmed by echocardiography core lab). * Sinus rhythm with mean resting heart rate 55-90 bpm. * Cardiac Index 0.5-2.4 measured by Innocor at screening and Day -1. Screening measurement confirmed by core lab. * Transvenous ICD for primary prevention in place and active (as long as it is not subcutaneous). * Optimal guideline-based medical therapy for HFrEF as judged by the Investigator, at stable doses for ≥2 weeks with no intention to change dosing during trial duration. Key Exclusion Criteria, Dose Escalation Phase: * Any cardiac rhythm that does or could interfere with ECG or TTE interpretation, including but not limited to permanent or persistent atrial fibrillation or flutter or paroxysmal atrial fibrillation or flutter with an episode in the last 3 months, frequent premature ventricular contractions, or atrial or ventricular pacing * Ongoing or planned mechanical circulatory support, treatment with any IV vasoactive drugs (vasodilators, inotropes, or vasopressors) or diuretics, and/or dialysis or hemofiltration or ultrafiltration. * Probable alternative explanations for symptoms or signs (e.g., but not limited to, known…