A Study of the Long-term Safety and Efficacy of Danicamtiv in Adults With Symptomatic Genetic and Familial Dilated Cardiomyopathy

Inclusion Criteria: 1. Completed 24 weeks of blinded study treatment (corresponding to the Week 26 Visit in DAN-301) and planned assessments in Part 1 or Part 2 of the DAN-301 study. 2. If sexually active, must use a highly effective birth control method from the Screening Visit through 3 months after the last dose. 3. Is able to understand and comply with the study procedures, understand the risks involved in the study, and provide written informed consent according to local and institutional guidelines before the first study-specific procedure. Exclusion Criteria: 1. Acute coronary syndrome or hemodynamically significant epicardial coronary disease, or coronary revascularization (percutaneous coronary intervention \[PCI\] or coronary artery bypass graft \[CABG\]) performed within 90 days of DAN-302 Screening Visit. 2. Recent (\<90 days) hospitalization for heart failure (HF) or use of IV diuretic. 3. Other recent (\<90 days) cardiovascular events (e.g., cerebrovascular accident). 4. Hospitalization for sepsis or other systemic infections within 30 days of Screening. A systemic infection includes suspected or confirmed infection associated with fever, hemodynamic instability, bacteremia, or organ dysfunction typically requires urgent evaluation and/or acute care. 5. Any malignancy requiring treatment after enrollment in DAN-301 that could limit patient's survival.