RecruitingPhase 2Drug trialPolatuzumab, Rituximab and Orelabrutinib Combination Regimen (PRO) in the Treatment of Elderly Frail Patients with Treatment-naive Non-GCB DLBCLThis prospective, single-arm, multicenter clinical study aims to enroll 30 frail elderly patients with Non-GCB DLBCL. This study is to evaluate the preliminary efficacy and safety of the combination of Polatuzumab, Rituximab, and orelabrutinib in this population. The primary endpoint is CR rate after induction therapy.