Registrational Study with Omecamtiv Mecarbil (AMG 423) to Treat Chronic Heart Failure with Reduced Ejection FractionGALACTIC-HF

-Subject has provided informed consent -Male or female, ≥ 18 to ≤ 85 years -History of chronic heart failure (HF), defined as requiring treatment for HF for a minimum of 30 days before randomization -Left ventricle ejection fraction (LVEF) ≤ 35%, per subjects most recent medical record, within 12 months prior to screening. -New York Heart Association (NYHA) class II to IV at most recent screening assessment. -Managed with HF standard of care (SoC) therapies consistent with regional clinical practice guidelines according to investigator judgment of subject’s clinical status -Current hospitalization with primary reason of HF OR one of the following events within 1 year of screening: hospitalization with primary reason of HF; urgent visit to emergency department (ED) with primary reason of HF. -Elevated B-type natriuretic peptide (BNP) or n-terminal-prohormone brain natriuretic peptide (NT-proBNP) Other Inclusion Criteria May apply

-Currently receiving treatment in another investigational device or drug study, or < 30 days since ending treatment on another investigational device or drug study(ies). Other investigational procedures while participating in this study are excluded. -Malignancy within 5 years prior to randomization with the following exceptions: localized basal or squamous cell carcinoma of the skin, cervical intraepithelial neoplasia, stage 1 prostate carcinoma, breast ductal carcinoma in situ. -Subject has known sensitivity to any of the products or components to be administered during testing Other Exclusion Criteria May apply