This is a multicenter, randomized, placebo-controlled, 2-part study to evaluate the safety and efficacy of AT-001 in adult patients (N=675) with Diabetic Cardiomyopathy at high risk of progression to overt heart failure.

The study consists of two consecutive parts: Part A and Part B. Part A will evaluate the safety and efficacy of two doses of AT-001 vs placebo. The primary objective of Part A is to demonstrate that AT-001 improves or prevents the decline of functional capacity in patients with Diabetic Cardiomyopathy. Part B is an extension of at least 12 months that will evaluate the safety and efficacy of chronic administration of AT-001 vs placebo in the same patients who had previously been evaluated in Part A. Assessments in Part B will include safety endpoints and exploratory clinical efficacy endpoints, i.e. death and hospitalization due to a cardiac event.

Inclusion Criteria:

• Type 2 Diabetes Mellitus
• Diabetic cardiomyopathy
• Peak VO2 < 75% of predicted normal value based on age and gender

Exclusion Criteria:

• Prior diagnosis or signs/symptoms of overt/symptomatic heart failure / stage C heart failure
• Prior echocardiogrphic measurement of ejection fraction (EF) < 40%
• Prior acute coronary syndrome (ACS), coronary artery bypass graft (CABG), percutaneous coronary intervention (PCI), coronary artery disease (CAD) or stroke
• Severe or moderate cardiac valve disease requiring intervention
• Clinically significant arrhythmia
• Prior diagnosis of congenital, infective, toxic, infiltrative, post-partum, or hypertrophic cardiomyopathy
• Blood pressure > 140 mmHg (systolic) or > 90 mmHg (diastolic) at screening
• HbA1c >8.5% at screening
• Severe disease that would impact the performance of a cardio-pulmonary exercise test