Epcoritamab Compared to Observation for Treating B-cell Lymphoma Patients Not in Complete Remission After CD19-directed CAR-T Therapy

PRIMARY OBJECTIVE: I. To compare complete response (CR) rate using the Lugano 2014 criteria for patients receiving epcoritamab versus observation alone in patients with aggressive B-cell lymphomas who achieved partial response (PR) post CAR-T therapy. SECONDARY OBJECTIVES: I. To compare the progression free survival (PFS) of epcoritamab determined by Lugano 2014 versus observation alone in patients with aggressive B-cell lymphomas post CAR-T. II. To compare event free survival (EFS) in patients who receive epcoritamab determined by Lugano 2014 versus observation alone in patients with aggressive B-cell lymphomas post CAR-T. III. To compare the overall survival (OS) of epcoritamab determined by Lugano 2014 versus observation alone in patients with aggressive B-cell lymphomas post CAR-T. IV. To compare the duration of response (DOR) of epcoritamab determined by Lugano 2014 versus observation alone in patients with aggressive B-cell lymphomas post CAR-T. V. To compare the duration of complete response (DoCR) of epcoritamab determined by Lugano 2014 versus observation alone in patients with aggressive B-cell lymphomas post CAR-T. VI. To compare the time to response (TTR) of epcoritamab determined by Lugano 2014 versus observation alone in patients with aggressive B-cell lymphomas post CAR-T. VII. To compare the objective response rate (ORR) of epcoritamab determined by Lugano 2014 versus observation alone in patients with aggressive B-cell lymphomas post CAR-T. VIII. To assess the safety and tolerability of epcoritamab post CAR-T in patients with aggressive B-cell lymphomas. EXPLORATORY OBJECTIVE: I. To assess outcomes based on CAR-T line of therapy and costimulatory domain of CAR-T construct. OUTLINE: Patients are randomized to 1 of 2 arms. ARM A: Patients receive epcoritamab subcutaneously (SC) on days 1, 8, 15, and 22 of cycles 1-3, days 1 and 15 of cycles 4-9, and day 1 of cycles 10-12. Treatment repeats every 28 days for up to 12 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo magnetic resonance imaging (MRI) at screening, undergo positron emission tomography (PET)/computed tomography (CT) and collection of blood samples throughout the trial, and undergo biopsy at screening and end of treatment. Patients may undergo CT or MRI during follow up. ARM B: Patients undergo observation per standard care. Patients also undergo MRI at screening, undergo PET/CT and collection of blood samples throughout the trial, and undergo biopsy at screening and end of treatment. Patients may undergo CT or MRI during follow up. After completion of study treatment, patients are followed up every 90 days for 1 year and then every 180 days for up to 5 years post-registration.