The purpose of this study is to evaluate the effect of dapagliflozin on the incidence of cancer therapeutics-related cardiac dysfunction in patients with breast cancer receiving anthracycline treatment.

This is a multicentre, randomised, double-blind, placebo-controlled phase III study, evaluating the effect of dapagliflozin versus placebo on prevention of cardiotoxicity in breast cancer patients undergoing anthracycline-based chemotherapy.

Inclusion Criteria:

• Age > 18 years and < 80 years.
• Diagnosis of invasive breast cancer [stage I-III] and planned anthracycline treatment within 60 days.
• Signed Informed Consent to participate in the study.

Exclusion Criteria:

• Urinary tract infection with the need for treatment with an antibiotic 48 hours before the scheduled start of anthracycline treatment.
• Recognised heart failure or symptoms which, in the opinion of the investigator may be a symptom of undiagnosed heart failure.
• Left ventricular ejection fraction < 50% at the time of the screening.
• Severe valvular heart disease.
• A history of clinically significant arrhythmia, including atrial fibrillation regardless of type (at discretion of the investigator).
• A history of stroke.
• Cardiomyopathy: congenital, post-inflammatory, toxic, infiltrative (e.g. amyloidosis, sarcoidosis, haemochromatosis), postnatal or hypertrophic.
• Pulmonary hypertension.
• Uncontrolled arterial pressure or systolic pressure < 80 mmHg at screening (at the discretion of the investigator).
• BMI > 40 kg/m2.
• Diagnosed type 1 or type 2 diabetes or fasting glucose ≥ 126 mg/dl or HbA1C ≥ 6,5% (48 mmol/mol).
• Pregnancy or breastfeeding.
• Lack of compliance to use highly effective method of birth control.
• Expected or possible treatment with epirubicin or liposomal doxorubicin within 12 months.
• Taking another study drug or drugs from the group of SGLT2 inhibitors up to 6 months before the screening visit.
• Taking semaglutide, liraglutide and metformin during the 30 days preceding the screening visit.
• eGFR < 25 ml/min/1.73m2 according to CKD EPI.
• Life expectancy < 12 months or cancer disease stage IV according to the TNM classification.
• Alanine transaminase or aspartate transaminase levels above 2.5 times the local norm.
• Anemia with Hemoglobin < 9 g/dl.
• Kidney failure > G2 (according to KDIGO classification).
• Liver disorders, Child-Pugh score > 4.
• Known, active infections with HIV, HBV, HCV, tuberculosis.
• Any other condition which, in the opinion of the investigator, makes it impossible to fulfill the requirements for participation in this study.