Role of bridging RT in relapsed/refractory diffuse large B-cell lymphoma undergoing CAR-T therapy: a multicenter...

Area of Science:

• Hematology
• Oncology
• Immunotherapy

Background:

• Chimeric antigen receptor (CAR)-T cell therapy offers a promising treatment for relapsed/refractory diffuse large B-cell lymphoma (DLBCL).
• The bridging regimen administered before CAR-T cell infusion can influence treatment efficacy and patient outcomes.
• Optimizing bridging strategies is crucial for maximizing the benefits of CAR-T cell therapy in DLBCL.

Purpose of the Study:

• To retrospectively evaluate the impact of radiotherapy (RT) bridging versus other bridging strategies on CAR-T cell therapy outcomes in patients with DLBCL.
• To compare CAR-T infusion rates, response to bridging, progression-free survival (PFS), overall survival (OS), and immune effector cell-associated neurotoxicity syndrome (ICANS) across different bridging groups.

Main Methods:

• Retrospective analysis of 148 patients with relapsed/refractory DLBCL undergoing leukapheresis for CAR-T manufacturing.
• Patients were categorized into three groups: RT-bridging (n=31), chemotherapy (CT)-bridging (n=84), and no-bridging or steroid-only (n=33).
• Comparison of CAR-T infusion rates, bridging response (LDH levels), 1-year PFS, 1-year OS, and ICANS incidence between groups.

Main Results:

• Higher CAR-T infusion rates were observed in the RT-bridging group (96.8%) compared to CT-bridging (89.2%) and no-bridging (78.8%).
• RT-bridging demonstrated significantly better 1-year PFS (51.2%) and OS (86.7%) compared to CT-bridging (PFS 28.2%, OS 52.7%).
• The CT-bridging group showed a higher incidence of ICANS (20.0%) compared to RT-bridging (3.3%) and no-bridging (7.7%).

Conclusions:

• Radiotherapy bridging is associated with a lower CAR-T dropout rate and reduced toxicity.
• RT-bridging may be a preferred strategy over chemotherapy bridging for DLBCL patients, particularly those with localized disease or a single dominant symptomatic site.
• Optimized bridging regimens, such as RT, can enhance CAR-T therapy efficacy and patient outcomes in DLBCL.