Metformin in Combination With Standard Induction Therapy for Large B-cell Lymphoma (DLBCL)

Inclusion Criteria: 1. Diagnosis of Diffuse Large B-cell Lymphoma (DLBCL) as documented by medical records and with histology based on criteria established by the World Health Organization a. subtyping is required for DLBCL 2. No prior therapy for diagnosis of DLBCL 3. Presence of radiographically measurable lymphadenopathy or extranodal lymphoid malignancy (defined as the presence of equal to or greater than 1 lesion that measures \>1.5 cm in the longest diameter and \> 1.0 cm in the longest perpendicular diameter assessed by CT or MRI) or bone marrow involvement 4. Eastern Cooperative Oncology Group performance score of 0-2 5. Life expectancy of at least 6 months 6. No history of medication dependent diabetes mellitus 7. Required screening laboratory data (within 4 weeks prior to start of study drug) - Exclusion Criteria: 1. Patients already on any class of anti-diabetic medication including metformin, insulin analogues, sulfonylureas, thiazolidinediones (TZDs) and the incretin-based therapies or clear need for therapeutic intervention based on fasting blood glucose 2. Known histological transformation from indolent non-Hodgkins Lymphoma (NHL) or chronic lymphocytic leukemia (CLL) to an aggressive form of NHL (ie, Richter transformation) 3. Double or triple hit lymphomas 4. Known active cent4ral nervous system or leptomeningeal lymphoma 5. Presence of known intermediate or high-grade myelodysplastic syndrome 6. History of a non-lymphoid malignancy within the last 3 years (see protocol for exceptions) 7. Evidence of ongoing systemic bacterial, fungal, or viral infection at the time of start of study 8. Ongoing, drug-induced liver injury, chronic active Hepatitis C Virus (HCV), chronic active Hepatitis B Virus (HBV), alcoholic liver disease, non-alcoholic steatohepatitis, primary biliary cirrhosis, ongoing extrahepatic obstruction caused by cholelithiasis, cirrhosis of the liver, or portal hypertension. 9. HIV positive 10. Ongoing inflammatory bowel disease 11. Ongoing alcohol or drug addiction 12. Pregnancy 13. History of prior allogeneic bone marrow progenitor cell or solid organ transplantation. \-