Rituximab, Cyclophosphamide, Vincristine and Prednisone (R-CHOP) Plus Metformin in Diffuse Large-B-cell Lymphoma

Patients with newly diagnosed diffuse large-B cell non Hodgkin lymphoma, irrespective of cell of origin status will receive metformin in combination to Rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (RCHOP) chemotherapy for 6 cycles, until response evaluation as reported elsewhere:

1.- Rituximab 375 mg/m2 IV, day 1. 2.- Cyclophosphamide 750 mg/m2 IV, day 1. 3.- Doxorubicin 50 mg/m2 IV day 1. 4.- Vincristine 1.4 mg/m2 IV (2 mg maximum dose). 5.- Prednisone 60 mg/m2 PO days 1-5. Six cycles every 21 days.

Metformin will be added and administered in an outpatient basis, starting with 425 mg twice a day for 1 week, followed by 850 mg twice a day for 1 week, and lastly 850 mg every 8 hours maximum dose until re-staging. Laboratory tests will be performed serially.

Inclusion criteria

• Patients with newly diagnosed nodal diffuse large-B cell non Hodgkin lymphoma according to the 2008 World Health Organization classification for lymphoid malignancies
• No previous treatment other than prednisone or equivalent glucocorticoid up to 60 mg/m2 for 14 days
• Good performance status (Eastern Cooperative Oncology Group scale 0-2)
• Life expectancy >6 months
• Independently of the diagnosis of diabetes mellitus (any type)

Exclusion criteria

• History of intolerance or hypersensitivity reactions to metformin
• Primary central nervous system lymphoma
• History of other previous malignant neoplastic diseases <5 years prior to enrollment
• Evidence of systemic infection at the time of study
• HIV, hepatitis C or B virus infection
• Aspartate transaminase or alanine transaminase >2x upper limit of normal, bilirubin >2.5 times upper limit of normal
• Serum creatinine >1.5 mg/dL or chronic renal disease
• Cardiac insufficiency (New York Heart Association scale >1 or ejection fraction <50%)
• History of transformation from an indolent lymphoma
• Pregnancy
• History of lactic acidosis or alcoholism