Pola-R-CHP Plus Sonrotoclax in Untreated BCL2-High/Double-Hit LBCL

Inclusion Criteria: * Patients with newly diagnosed large B-cell lymphoma confirmed by histopathology, CD20-positive, excluding central nervous system lymphoma; * Patients aged 18 to 75 years; * International Prognostic Index score of 2 to 5; * Patients with high BCL-2 expression or double-hit lymphoma characteristics; * No prior anti-tumor treatment of any type; * Estimated survival time ≥ 6 months; * Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2; * Measurable lesions confirmed by radiological examination, defined as: at least one lymph node lesion with the longest diameter \> 1.5 cm, or at least one extranodal lesion with the longest diameter \> 1.0 cm, and at least two accurately measurable perpendicular diameters; * Patients or their legal representatives must provide written informed consent before conducting any study-specific examinations or procedures; * No prior treatment for lymphoma (except glucocorticoids). Exclusion Criteria: * Prior solid organ transplantation or stem cell transplantation; * Complicated with uncontrolled coagulation disorders, connective tissue diseases, severe infectious diseases, etc.; * Suspected active or latent tuberculosis (confirmed by a positive interferon-gamma release assay); * Any of the following abnormal laboratory test values (unless these abnormalities are all caused by the underlying lymphoma): * Neutrophils \< 1.0×10⁹/L; * Platelets \< 75×10⁹/L; * Serum AST and ALT ≥ 2.5× upper limit of normal (ULN); * Total bilirubin ≥ 1.5×ULN; * Serum creatinine clearance \< 30 mL/min (calculated using the Cockcroft-Gault formula); * Uncontrolled or significant cardiovascular diseases, including but not limited to: * Left ventricular ejection fraction (LVEF) \< 50%; * Primary cardiomyopathy, such as dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, etc.; * Clinically significant QTc prolongation, with QTc interval \> 470 ms (females) or 480 ms (males), second-degree type II atrioventricular block, or third-degree atrioventricular block; * Current or past history of central nervous system (CNS) diseases, such as stroke, epilepsy, CNS vasculitis, or neurodegenerative diseases. However, participants with a history of stroke who have not had a stroke or transient ischemic attack in the past 2 years and have no residual neurological deficits as judged by the investigator are allowed to participate in the study; * Patients with mental illness or other patients known or suspected to be unable to fully comply with the study protocol; * Patients infected with human immunodeficiency virus (HIV); * History of other malignant tumors that may affect protocol compliance or interpretation of results: * Participants with a history of cured basal or squamous cell carcinoma of the skin, melanoma, or carcinoma in situ of the cervix at any time before the study are eligible to participate; * Participants with a history of untreated low-grade early-stage prostate cancer (Gleason score ≤ 6, Stage 1 or 2) at any time before the study are eligible to participate; * Participants who received adjuvant endocrine therapy for non-metastatic, hormone receptor-positive breast cancer for ≥ 2 years before enrollment are eligible to participate; * Participants with any other malignant tumor cured by appropriate radical treatment and in remission without treatment for ≥ 2 years before enrollment are eligible to participate; * History of immune-related adverse events following prior immunotherapy drug-related treatment, as follows: known active bacterial, viral, fungal, mycobacterial, parasitic, or other infections (excluding onychomycosis) at study enrollment, or major infections within 4 weeks before the start of Cycle 1; * Active hepatitis B virus (HBV) infection (positive result by PCR). For patients with positive HBsAg test results, HBV DNA test is required; if HBV DNA \< 10³ IU/ml, they can be enrolled. If HBsAg test result is negative but HBcAb test is positive (regardless of HBsAb status), HBV DNA test is also required; if HBV DNA \< 10³ IU/ml, they can be enrolled; * Positive hepatitis C test result (serological test for hepatitis C virus \[HCV\] antibody): * Eligibility to participate is only allowed if the PCR test result for HCV RNA is negative in patients with positive HCV antibody; * Participants with a history of progressive multifocal leukoencephalopathy (PML); * Currently pregnant or breastfeeding, or planning to become pregnant during the study or within 12 months after the last dose; * Other concurrent and uncontrolled medical conditions that the investigator believes will affect the patient's participation in the study.