Empagliflozin add-on to Insulin in Type 1 Diabetes Mellitus Over 28 Days

Inclusion criteria: * Signed and dated written informed consent * Male or female patient receiving insulin for treatment of T1DM for at least 12 months * C-peptide \< 1.5 ng/mL * Age 18 to 65 years * HbA1c of 7.5% to 10.5% * Multiple daily injections (MDI) of any type of insulin * Willing to follow an established and individualized carbohydrate counting method and an insulin administration algorithm * Body Mass Index of 18.5 to 35.0 kg/m2 * Estimated glomerular filtration rate 60 to 150 mL/min/1.73 m² * Able and willing to perform study assessments according to investigator's judgement * Compliance with trial drug administration 80% to 120% during run-in period * Willing not to take any paracetamol containing drugs during the trial Exclusion criteria: * Acute symptomatic urinary tract infection or genital infection, chronic or recurrent cystitis * History of type 2 diabetes mellitus, maturity onset diabetes of the young (MODY), pancreatic surgery or chronic pancreatitis * Pancreas, pancreatic islet cells or renal transplant recipient * Type 1 diabetes mellitus treatment with any other antihyperglycaemic drug except insulin within last 3 months or history of clinically relevant hypersensitivity * Occurrence of hypoglycaemia that required hospitalization or treatment by an emergency physician or paramedic within last 3 months * Hypoglycaemia unawareness or frequent episodes of unexplained hypoglycaemia * Occurrence of diabetic ketoacidosis that required hospitalization or treatment by an emergency physician or paramedic within last 12 months * History of macrovascular disease including cardiovascular, cerebrovascular and peripheral artery disease * Autonomic neuropathy with gastroparesis * Brittle diabetes * Liver disease * Treatment with anti-obesity drugs, surgery or aggressive diet regimen leading to unstable body weight * Treatment with systemic corticosteroids * Change in dose of thyroid hormones within last 6 weeks or planned change or initiation of such a therapy * Medical history of cancer or treatment for cancer in the last five years * Blood dyscrasias or any disorders causing haemolysis or unstable red blood cells * Alcohol or drug abuse that would interfere with trial participation or any ongoing clinical condition that would jeopardize patient's or site personnel's safety or study compliance * Intake of an investigational drug in another trial within last 30 days * Not able to understand and comply with study requirements * Pre-menopausal women who are nursing or pregnant or of child-bearing potential and are not practising an acceptable method of birth control