Study on Predicting Response to Standard First-Line Treatment in Diffuse Large B-Cell Lymphoma (DLBCL) Patients Using ctDNA Combined With PET

This multicenter, prospective, multi-cohort clinical study was designed to evaluate the relevance of combined test results for PET / CT and ctDNA and patient survival outcomes in patients with naive DLBCL after 2 cycles of treatment with the standard first-line therapy. The study plans to enroll 80 patients with newly diagnosed, CD20-positive DLBCL who have not received prior systemic therapy. Participants will be stratified into two cohorts based on baseline International Prognostic Index (IPI) scores, receiving either the NMPA-approved R-CHOP regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) or the NMPA-approved Pola-R-CHP regimen (polatuzumab vedotin, rituximab, cyclophosphamide, doxorubicin, prednisone) for 6 cycles. PET/CT imaging will be performed at baseline, Cycle 2 Day 20 (C2D20), and 6 weeks after Cycle 6 Day 21 (C6D21), while whole-blood samples for circulating tumor DNA (ctDNA) analysis will be collected at baseline, Cycle 3 Day 1 (C3D1), and C6D21.The primary endpoint of this study is the association of PET / CT and ctDNA test results with progression-free survival (PFS) after 2 cycles of RCHOP or Pola-R-CHP regimen in treatment-naive patients with diffuse large B cell lymphoma (DLBCL). Secondary endpoints are the correlation between the combination of PET / CT and ctDNA with tumor remission after 2 cycles of RCHOP or Pola-R-CHP in DLBCL patients, association of PET / CT and ctDNA with RCHOP or Pola-R-CHP and assessment of the CR rate, ORR, EFS and safety of real-world RCHOP or Pola-R-CHP regimen in treatment-naive DLBCL patients.