A clinical trial to compare how well treatment with polatuzumab vedotin plus rituximab plus gemcitabine plus oxaliplatin (Pola-R-GemOx) works in people with diffuse large B-cell lymphoma versus treatment with R-GemOx alone

A Study to Evaluate the Safety and Efficacy of Polatuzumab Vedotin in Combination With Rituximab, Gemcitabine and Oxaliplatin Compared to Rituximab, Gemcitabine and Oxaliplatin Alone in Participants With Relapsed or Refractory Diffuse Large B-Cell Lymphoma