A Phase II Trial of 4 vs 6 Cycles of CHP Combined With Polatuzumab Vedotin-Rituximab in Untreated DLBCL Patients With IPI 0-1

Inclusion Criteria: * Newly diagnosed, untreated, biopsy-proven CD20 positive diffuse large B-cell lymphoma (DLBCL) * Age ≥18yo and ≤80yo at the time of signing consent * International Prognostic Index (IPI) score 0-1 * ECOG 0-2 * Have measurable disease on a pre-chemotherapy PET/CT, defined as at least one bi-dimensionally measurable nodal lesion of \>1.5cm in longest dimension, or at least one bi-dimensionally measurable extranodal lesion of \>1.0cm in longest dimension * Life expectancy greater than or equal to (\>/=)12 months * Left ventricular ejection fraction (LVEF) \>/= 50 percent (%) on cardiac multiple-gated acquisition (MUGA) scan or cardiac echocardiogram (ECHO) * Adequate hematologic function * Female participants: Agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive methods and refrain from donating eggs. * Male participants: agreement to remain abstinent (refrain from heterosexual intercourse) or use a condom and agreement to refrain from donating sperm. Exclusion Criteria: * Patients with central nervous system or primary mediastinal lymphoma, and patients with transformed lymphoma. * Patients with uncontrolled cardiovascular and cerebrovascular diseases, coagulation disorders, connective tissue diseases, severe infectious diseases, etc. * Pregnant or lactating women. * Known history of human immunodeficiency virus (HIV) or active hepatitis C virus (HCV; positive by RNA polymerase chain reaction \[PCR\]) infection. * Patients with concurrent other tumors or a history of tumors, or who have received anti-tumor treatment (including major surgery) within the last 4 weeks. * Allergic reactions to polatuzumab vedotin. * Other conditions where the investigator deems the patient ineligible for this study.