Epcoritamab Plus Standard of Care Platinum-Based Chemotherapy and Autologous Hematopoietic Cell Transplant for the Treatment of Relapsed or Refractory Large B-cell Lymphoma

Inclusion Criteria: * Participants must have histologically or cytologically confirmed R/R LBCL * Can include diffuse large B-cell lymphoma (DLBCL) (not otherwise specified \[NOS\] or with concurrent MYC and BCL2 rearrangements), high-grade B-cell lymphoma (HGBCL) (NOS or with MYC and BCL2 or BCL6 rearrangements) and transformed follicular lymphoma (FL) and nodal marginal zone lymphoma (MZL) * Histological confirmed CD20+ relapsed/ refractory large cell lymphoma * Must have had relapsed or refractory disease following standard frontline chemotherapy. Refractory disease is defined as large cell lymphoma not achieving complete remission, progressing, or relapsing within 6 months after first-line chemotherapy based on PET/CT per the Lugano criteria. Relapsed disease is defined as disease that recurs beyond 6 months after completion of initial chemotherapy based on PET/CT per the Lugano criteria * Have received 1 or more prior lines of systemic therapy for the treatment of large cell lymphoma. NOTE: Prior radiation therapy or systemic corticosteroids will not be considered a line of therapy * Candidate for platinum-containing chemotherapy (RICE, RDHAP/X, or R-Gem/Ox) pre-autologous hematopoietic cell transplantation (autoHCT) followed by autoHCT as per institutional guidelines * Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 (Karnofsky ≥ 60%) * Measurable disease via diagnostic quality CT or PET/CT with at least 1 node having the longest diameter (LDi) greater than (\>) 1.5 centimeter (cm) or 1 extranodal lesion with LDi \> 1 cm (per the Lugano criteria 2014) * Aged ≥ 18 at the time of consent * Creatinine clearance (CrCl) ≥ 45 mL/min (Cockcroft-Gault) * Serum alanine aminotransferase (ALT) ≤ 3 x upper limit of normal (ULN) * Serum aspartate aminotransferase (AST) ≤ 3 x ULN * Bilirubin ≤ 1.5 x ULN unless due to Gilbert's syndrome or controlled autoimmune hemolytic anemia (not requiring immunosuppressive other than ≤ 20 mg of prednisolone daily) * Note: Patients with Gilbert's syndrome may be included if total bilirubin is ≤ 3 x ULN and direct bilirubin is ≤ 1.5 x ULN * Hemoglobin ≥ 8.0 g/dL * Note: Blood transfusion may be administered during Screening to meet this requirement only if anemia is due to marrow involvement of non-Hodgkin lymphoma (NHL) * Absolute neutrophil count ≥ 1000/uL * Note: Growth factor support is allowed to meet this requirement at Screening only if directly attributable to NHL infiltration of the bone marrow, proven by bone marrow biopsy * Platelet count ≥ 75,000/uL or ≥ 50,000/uL if bone marrow (BM) involvement or splenomegaly * Note: Transfusion may be administered during screening to meet this requirement * prothrombin time (PT)/international normalized ratio (INR)/activated partial thromboplastin time (aPTT) ≤ 1.5 x ULN * Note: If any of the above-mentioned cytopenias are present, there should be no evidence of myelodysplastic syndrome (MDS) or hypoplastic bone marrow * HIV-infected patients on effective anti-retroviral therapy with stable viral load and CD4 count for 1 year prior to enrollment are eligible for this trial. Testing for HIV viral load and antibody at screening is mandatory * Patients with a history of chronic hepatitis B virus (HBV) infection, must have an undetectable HBV viral load on suppressive therapy, if indicated. Patients with evidence of prior HBV but who are polymerase chain reaction (PCR)-negative are permitted in the trial but should receive prophylactic antiviral therapy. Patients with a history of hepatitis C virus (HCV) infection must have been treated and cured. For patients with HCV infection who are currently on treatment, the HCV viral load must be undetectable to be eligible for this trial. Patients who received treatment for HCV that was intended to eradicate the virus may participate if hepatitis C ribonucleic acid (RNA) levels are undetectable. Testing for HBV and HCV is mandatory at screening * Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of study participation, and for 12 months after the last dose of epcoritamab * Provision of signed and dated informed consent form Exclusion Criteria: * Any adverse event (AE) related to the previous large cell lymphoma therapy which has not recovered to grade ≤ 1 (Common Terminology Criteria for Adverse Events \[CTCAE\] version \[v.\] 5.0) or baseline by cycle 1 day 1 (C1D1), except alopecia and non-clinically significant laboratory abnormalities * Uncontrolled intercurrent illness (including infection) * Known active central nervous system or meningeal (including leptomeningeal) involvement. Patients diagnosed with central nervous system (CNS) disease who achieved and maintained CNS complete response (CR) at the time of relapse are eligible. Lumbar puncture must be done in this case prior to study entry (within 90 days of enrollment) to demonstrate CNS CR status. Tests to investigate CNS involvement are required otherwise only if clinically indicated (i.e. disease suspected on basis of symptoms or other findings) * Receiving any other investigational treatments * Previous treatment with any bispecific T-cell engager with or without chemotherapy * Treatment with an investigational drug within 4 weeks or 5 half-lives, whichever is longer, prior to the first dose of epcoritamab * Concurrent use of other anti-cancer agents or treatments except for certain therapeutics (e.g., prostate, breast hormonal-based therapy) per the treating physician's discretion * Standard agents within 2 weeks or 5 half-lives, whichever is shorter, prior to the first dose of epcoritamab (excluding anti-CD20 monoclonal antibodies \[mAbs\], which can be administered until first full dose of epcoritamab); or * CAR-T cell therapy within 30 days prior to the first dose of epcoritamab * Palliative radiation is permitted only if on non-target lesio