A Single-Arm, Open-Label, Multicenter Phase II Trial of CRP Regimen (Chidamide, Rituximab, Polatuzumab Vedotin) in Treating Elderly Patients with Previously Untreated Double-Positive Diffuse Large B-Cell Lymphoma

This is a single-arm, open-label, multicenter Phase II trial to evaluate the feasibility, efficacy, and safety of the CRP regimen (Chidamide, Rituximab, Polatuzumab Vedotin) in treating elderly patients with previously untreated double-expressor diffuse large B-cell lymphoma.

Inclusion Criteria:

1. Patients aged ≥70 years, or patients aged 60-69 years with an ECOG performance status score of 2-4. Both males and females are eligible.

2. No prior treatment for DLBCL, including chemotherapy, targeted therapy, immunotherapy, local radiotherapy directed at the lymphoma (excluding palliative radiotherapy for symptom relief), or surgical therapy (excluding diagnostic biopsy or surgery not targeting the lymphoma).

3. Histopathological confirmation meeting all of the following conditions:

   1. Diagnosis of diffuse large B-cell lymphoma (DLBCL) with CD20 positivity; concurrent positive expression of C-MYC and Bcl-2 (double-expressor phenotype).
   2. At least one measurable lesion positive on ¹⁸F-FDG PET-CT scan according to the Lugano 2014 criteria for Hodgkin and non-Hodgkin lymphoma.

4. Laboratory tests at screening must meet the following criteria, unless the investigator attributes abnormalities to lymphoma (no corrective or supportive therapy for these parameters within 2 weeks prior to assessment):

   1. Hematology: Hb ≥90 g/L, ANC ≥1.5 × 10⁹/L, PLT ≥90 × 10⁹/L.
   2. Biochemistry: Cr ≤1.5 ×ULN; TBIL ≤1.5 × ULN; ALT and AST ≤2.5 × ULN (for patients with liver involvement: ≤5 × ULN).

5. Life expectancy of at least 6 months, as judged by the investigator.

6. Ability to understand and voluntarily provide written informed consent.

Exclusion Criteria:

1. History of or concurrent other active malignancies.
2. Prior treatment with Chidamide and/or R-CHOP. Contraindication to any component of CHOP, including prior anthracycline therapy. History of severe hypersensitivity or anaphylaxis to humanized or murine monoclonal antibodies, or known sensitivity/allergy to murine products.
3. Current diagnosis of any of the following: Follicular lymphoma grade 3B; B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and classical Hodgkin lymphoma (grey zone lymphoma); Primary mediastinal (thymic) large B-cell lymphoma; Burkitt lymphoma; Central nervous system (CNS) lymphoma (primary or secondary); Primary effusion DLBCL; Primary cutaneous DLBCL, leg type.
4. History of myocardial infarction, unstable angina, or other clinically significant cardiac disease within 12 months prior to signing informed consent; or prior coronary angioplasty/stenting within 12 months.
5. Clinically uncontrolled active infection (bacterial, fungal, or viral) or organ hemorrhage.
6. Pregnant or lactating women.
7. Participation in any other clinical trial within 6 months prior to signing informed consent.
8. Any other condition that, in the opinion of the investigator, makes the patient unsuitable for participation in this study.