A Study of JNJ-80948543 in Combination With Other CD3 T-Cell Engagers in Participants With Relapsed/Refractory B-Cell Non-Hodgkin Lymphoma (R/R B-Cell NHL)

The purpose of this study is to determine the recommended phase 2 regimen (RP2R) for JNJ-80948543 in combination with JNJ-75348780 (Part 1: Dose Escalation) and to further assess the safety of JNJ-80948543 at the RP2R in combination with JNJ-75348780 (Part 2: Dose Expansion).

Inclusion Criteria: * Histologic documentation of diffuse large B-cell lymphoma (DLBCL), including high-grade B-cell lymphoma and DLBCL arising from indolent lymphoma. All participants must have received at least 2 prior lines of therapy * Participants must have measurable disease as defined by the appropriate disease response criteria * Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1 * Hematologic laboratory parameters must meet the required criterias and the values must be without a transfusion or growth factors for at least 7 days prior to the first dose of study drug * Participants of childbearing potential must have a negative highly sensitive serum pregnancy test (beta (β)-human chorionic gonadotropin) at screening and within 24 hours before the first dose of study treatment and must agree to further serum or urine pregnancy tests during the study Exclusion Criteria: * Known active central nervous system involvement (CNS) or leptomeningeal involvement * Prior solid-organ transplantation * Autoimmune or inflammatory disease requiring systemic steroids or other immunosuppressive agents (example, methotrexate or tacrolimus) within 1 year prior to first dose of study drug * Toxicity from prior anticancer therapy has not resolved to baseline levels or to Grade \<= 1 (except alopecia, vitiligo, peripheral neuropathy, or endocrinopathies that are stable on hormone replacement, which may be Grade 2) * Clinically significant pulmonary compromise defined as the need for supplemental oxygen to maintain adequate oxygenation * Evidence of clinically significant and/or symptomatic infection (viral, bacterial, or fungal) at the time of study drug initiation. Anti-microbial treatment for infection must be discontinued at least 7 days before the first dose of study drug