A Study of MT-2111 in Patients With Relapsed/Refractory DLBCL

Inclusion Criteria: * Patients who were diagnosed pathologically with DLBCL, NOS, DLBCL transformed from indolent B-cell lymphoma, or high-grade B-cell lymphoma with DLBCL morphology and with MYC and BCL2 and/or BCL6 rearrangements, based on the 2017 WHO classification. * Patients with relapsed or refractory disease despite 2 or more prior systemic therapies. * Japanese patients aged ≥ 18 years at the time of informed consent. For Japanese subjects, it should be confirmed that the parents who are related by blood to the subject must be Japanese. * Patients who have a lesion that can be assessed for staging and evaluated for response according to the Lugano criteria (2014). A lesion that has received radiotherapy as the most recent treatment will be considered as a measurable lesion only when progression has been documented following completion of the radiotherapy. * Patients with an Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2 at screening. Exclusion Criteria: * Patients with a pathological diagnosis of Burkitt's lymphoma. * Patients with bulky disease with the longest dimension of ≥ 10 cm. * Patients with a history or complication of post-transplant lymphoproliferative disorders. * Patients with lymphoma with active central nervous system involvement at the time of screening, including leptomeningeal disease. * Patients complicated with other active malignancies or patients with a history of other malignancies within 3 years before informed c…