An Open-Label, Randomized, Parallel-Group Study of Bendamustine Hydrochloride and Rituximab (BR) Compared with Rituximab, Cyclophosphamide, Vincristine, and Prednisone (R-CVP) or Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone (R-CHOP) in the First-Line Treatment of Patients with Advanced Indolent Non-Hodgkin's Lymphoma (NHL) or Mantle Cell Lymphoma (MCL).

Name of intervention being studied: Bendamustine Hydrochloride (administered in combination with Rituximab) Patients will be randomly assigned to either investigational treatment (BR) or standard treatment (R-CVP or R-CHOP). Six cycles of treatment are planned, with a maximum of eight treatment cycles permitted as the discretion of the investigator and after discussion with the sponsor or sponsor's designee. If randomised to the investigational treatment arm, patients will receive Bendamustine Hydrochloride at 90mg per metre squared (body surface area) intravenously on days 1 and 2 of each 28-day cycle. Additionally, patients will receive Rituximab at 375mg per metre squared intravenously on day 1 of every cycle of treatment. The Bendamustine and Rituximab are infused separately: * Bendamustine: approximately 30 minute infusion * Rituximab: Infusion duration will vary depending on the size (height and weight) of the patient: - Cycle 1 - approximately 3-5 hours - Cycle 2 onwards - approximately 2-4 hours (if Cycle 1 was well tolerated)