Diffuse Large B-cell Lymphoma (DLBCL) is a common hematologic malignancy. Even after standard first-line treatment, approximately 40% of patients will experience relapse. Currently, polatuzumab vedotin (pola) has been incorporated into DLBCL treatment (both for newly diagnosed and relapsed cases). However, for patients whose disease progresses after pola-containing regimens, the subsequent treatment options, efficacy, and survival outcomes remain unclear. Understanding these real-world scenarios is of great significance, as it can guide clinicians in developing better and more tailored treatment strategies for patients in the future.

Therefore, we plan to conduct this real-world study titled "Salvage Treatment Strategies and Clinical Outcomes in Diffuse Large B-cell Lymphoma After Failure of Polatuzumab Vedotin-based Combination Therapy", aiming to obtain real-world data from the Chinese population.

This is a retro- and prospective, observational study

Inclusion Criteria:

• Patients diagnosed with DLBCL
• Age ≥18 years
• Prior treatment with a polatuzumab vedotin (pola)-containing regimen and confirmed disease progression (refractory/relapsed) after this therapy.
• Availability of complete electronic medical records and ability to be contacted via telephone.
• Full understanding of the study, voluntary participation, and willingness to sign the informed consent form.

Exclusion Criteria:

• Patients who have not received pola-based regimen treatment.
• Incomplete electronic medical records or unreachable by telephone.

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