RecruitingPhase 2Biological interventionLoncastuximab Tesirine for the Treatment of Relapsed or Refractory B-Cell MalignanciesThis phase II trial tests whether loncastuximab tesirine works to shrink tumors in patients with B-cell malignancies that have come back (relapsed) or does not respond to treatment (refractory). Loncastuximab tesirine is a monoclonal antibody, called loncastuximab, linked to a chemotherapy drug, called tesirine. Loncastuximab is a form of targeted therapy because it attaches to specific molecules (receptors) on the surface of cancer cells, known as CD19 receptors, and delivers tesirine to kill them.