Empagliflozin (BI 10773) Dose Finder Study in Japanese Patients With Type 2 Diabetes Mellitus

Inclusion criteria: * Diagnosis of type 2 diabetes mellitus prior to informed consent * Male and female patients on diet and exercise regimen who are: 1. drug-naïve, defined as no antidiabetic drugs for 10 weeks prior to informed consent. 2. pre-treated with one oral antidiabetic drug; the present antidiabetic therapy has to be unchanged for 10 weeks prior to informed consent. * HbA1c at Visit 1a: 1. for patients who are drug naïve: HbA1c \>=7.0 to =\<10.0% 2. for patients treated with one oral antidiabetic drug: HbA1c \>=6.5 to =\<9.0% * HbA1c of \>=7.0% and =\<10% at Visit 2 (start of run-in) Exclusion criteria: * Uncontrolled hyperglycaemia with a glucose level \>240 mg/dL (\>13.3 mmol/L) after an overnight fast during wash-out/placebo run-in period and confirmed by a second measurement (not on the same day). * Acute coronary syndromes, stroke or transient ischaemic attack within 12 weeks prior to informed consent * Impaired renal function, defined as calculated eGFR \<60 ml/min (MDRD formula) during screening and/or wash-out period and/or run-in phase. * Bariatric surgery within the past 2 years and other gastrointestinal surgeries that induce chronic malabsorption * Blood dyscrasias or any disorders causing hemolysis or unstable Red Blood Cell (e.g. malaria, babesiosis, haemolytic anemia) * Treatment with anti-obesity drugs (e.g. sibutramine, mazindol) 12 weeks prior to informed consent or any other treatment at the time of screening (i.e. surgery, aggressive diet regimen, etc.) leading to unstable body weight