RecruitingPhase 2Drug trialPola-R2 in Newly Diagnosed Non-fit Elderly DLBCL PatientsThis is a prospective, single-arm, phase II study, and the purpose of this study is to evaluate the efficacy and safety of Pola-R2 regimen in newly diagnosed elderly diffuse large B cell lymphoma classified into un-fit or frail group by comprehensive geriatric assessment(CGA).