The Efficacy and Safety of Pola-ZR2 Versus ZR2 in the Treatment of Old Patients With de Novo Diffuse Large B-cell Lymphoma

This study will evaluate the efficacy and safety of Pola-ZR2 versus ZR2 in the treatment of elderly de novo diffuse large B-cell lymphoma patients. Subjects will be randomly assigned 1:1 to Pola-ZR2 or ZR2 regimen. The stratification will be performed according to international prognostic index (2-3 / 4-5). Patients in Pola-ZR2 group will receive 6 cycles of polatuzumab vedotin 1.8 mg/kg, day 2 on the 1st cycle and day 1 on the 2nd to 6th cycle, zanubrutinib 160mg bid, day 1-21, orally, lenalidomide 25mg qd, day 2-11, orally, rituximab 375mg/m², day 1, intravenously, every 21 days. Patients in ZR2 group will receive 6 cycles of zanubrutinib 160mg bid, day 1-21, orally, lenalidomide 25mg qd, day 2-11, orally, rituximab 375mg/m², day 1, intravenously, every 21 days. Patients who receive complete response or partial response after induction therapy will receive lenalidomide 25 mg qd po during 1-10 days in every 21 days for 2 years.