Use of LOncastuximab Tesirine in patients with RElapsed/Refractory Diffuse Large B-Cell LYmphoma (DLBCL) or High Grade B-Cell Lymphoma (HGBCL) who have progressive disease after CAR T-cell treatment - LORELY

You likely can't join if

• 1. Known history of hypersensitivity to or positive serum human antidrug antibody (ADA) to a CD19 antibody. 2. Females who are pregnant or lactating.3. Active second primary malignancy other than non-melanoma skin cancers, non-metastatic prostate cancer, in situ cervical cancer, ductal or lobular carcinoma in situ of the breast, or other malignancy that the Sponsor's medical monitor and Investigator agree and document should not be exclusionary. 4. Lymphoma with active CNS involvement at the time of screening, including leptomeningeal disease. 5. Bulky disease, defined as largest tumour diameter >10 cm. 6. Known seropositive and requiring anti-viral therapy for human immunodeficiency (HIV) virus, hepatitis B virus (HBV), or hepatitis C virus (HCV). 7. Clinically significant third space fluid accumulation (i.e., ascites requiring drainage or pleural effusion that is either requiring drainage or associated with shortness of breath) 8. Significant medical comorbidities, including but not limited to, uncontrolled hypertension (blood pressure ≥160/100 mm Hg repeatedly), unstable angina, congestive heart failure (greater than New York Heart Association class II), electrocardiographic evidence of acute ischemia, coronary angioplasty or myocardial infarction within 6 months prior to screening, uncontrolled atrial or ventricular cardiac arrhythmia, poorly controlled diabetes, or severe chronic pulmonary disease. 9. Active autoimmune disease, motor neuropathy considered of autoimmune origin, and other central nervous system (CNS) autoimmune disease. 10. History of Steven's Johnson's syndrome or toxic epidermal necrolysis syndrome. 11. Major surgery, radiotherapy, chemotherapy or other antineoplastic therapy within 14 days prior to start of study drug (C1D1), except shorter if approved by the Sponsor. 12. Planned live vaccine administration after starting study drug (C1D1). 13. Use of any other experimental medication within 14 days prior to start of study drug (C1D1). 14. Failure to recover to Grade ≤1 (Common Terminology Criteria for Adverse Events version 5.0 [CTCAE v5.0]) from acute nonhematologic toxicity (Grade ≤2 neuropathy or alopecia) due to previous therapy prior to screening. 15. Any other significant medical illness, abnormality, or condition that would, in the Investigator’s judgment, make the patient inappropriate for study participation or put the patient at risk.