Prospective Multicenter Observational Study of Patients with Relapsed or Refractory Diffuse Large B-cell Lymphoma Starting Second- or Third-line Therapy and not Receiving Autologous Stem Cell Transplant.

Criteria: Inclusion Criteria: 1. Age ≥18 years at the time of diagnosis of R/R DLBCL 2. Initiated or initiating tafasitamab treatment 3. R/R DLBCL patients who have received at least one (1) prior line of treatment for DLBCL 4. Histologically confirmed DLBCL such as: a) DLBCL not otherwise specified (NOS) b) T-cell histiocyte-rich large B-cell lymphoma (THRLBCL) c) Epstein-Barr virus (EBV)-positive DLBCL of the elderly d) Composite lymphoma with a DLBCL component with a subsequent DLBCL relapse, according to Revised European American Lymphoma (REAL)/World Health Organization (WHO) classification e) Patients with evidence of histological transformation to DLBCL from an earlier diagnosis of low-grade lymphoma (i.e., an indolent pathology such as follicular lymphoma [FL], marginal zone lymphoma [MZL], chronic lymphocytic leukemia [CLL]) with a subsequent DLBCL relapse f) High-grade B-cell lymphoma: i) DLBCL with MYC and BCL2 or BCL6 translocation (double-hit) and MYC and BCL2 and BCL6 translocations (triple-hit) ii) High-grade B-cell lymphoma, NOS 5. Signed and dated ICF by the patient or the patient's Legally Acceptable Representative (LAR), for patients with prospective data collection, as applicable. For deceased or otherwise unreachable patients, no informed consent will be obtained for data collection in the study, provided that the competent Independent Ethics Committee (IEC)/Institutional Review Board (IRB) has provided favorable opinion and that any other local regulatory requirements on this matter are met Exclusion Criteria: • Initiated or initiating tafasitamab treatment in the context of an interventional study.