Belantamab Mafodotin In Plasmablastic Lymphoma & ALK+ Large B-Cell Lymphoma

Inclusion Criteria: * Participants must have relapsed or refractory plasmablastic lymphoma or ALK+ large Bcell lymphoma by WHO criteria. * Participants must have measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter \[LDi\] to be recorded for non-nodal lesions and short axis for nodal lesions) as ≥15 mm in LDi for nodal disease or ≥10 mm in LDi for extranodal lesions. * Participants must have received prior systemic lymphoma therapy. * Age ≥18 years. Because no dosing or adverse event data are currently available on the use of belantamab mafodotin in participants \<18 years of age, children are excluded from this study. * ECOG performance status ≤2 (Karnofsky ≥60%, see Appendix A). * Participants must have adequate marrow function as defined below (unless abnormalities are considered related to marrow and/or splenic involvement by lymphoma): * absolute neutrophil count ≥1,000/mcL * platelets ≥50,000/mcL * hemoglobin ≥ 8.0 g/dL * Participants must have adequate organ function as defined below: * total bilirubin ≤ 1.5 X institutional upper limit of normal (ULN); (Isolated bilirubin ≥1.5xULN is acceptable if bilirubin is fractionated and direct bilirubin \<35%) * AST(SGOT)/ALT(SGPT) ≤2.5 × institutional ULN * Spot urine (albumin/creatinine) \<500 mg/g (56 mg/mmol) OR * Urine Dipstick Negative/trace (if ≥1+ only eligible if confirmed ≤ 500 mg/g (56 mg/mmol) by albumin/creatinine ratio (spot …