A Study of JNJ-75348780 in Participants With Non-Hodgkin Lymphoma (NHL) and Chronic Lymphocytic Leukemia (CLL)

You may not be if

• Eastern Cooperative Oncology Group (ECOG) performance status Grade of 0 or 1
• Cardiac parameters within the following range: corrected QT interval (QTc intervals corrected using Fridericia's formula \[QTcF\]) less than or equal to (\<=) 480 milliseconds (ms) based on the average of triplicate assessments performed no more than 5 (plus minus \[+ -\] 3) minutes apart
• Women of childbearing potential must have a negative highly sensitive serum pregnancy test (Beta human chorionic gonadotropin) at screening and prior to the first dose of study drug
• Women must be: a) not of childbearing potential, b) of childbearing potential and practicing a highly effective, preferably user independent method of contraception (failure rate of less than (\<) 1 percent (%) per year when used consistently and correctly) and agrees to remain on a highly effective method while receiving study drug and until 90 days after last dose
• Known central nervous system (CNS) involvement with lymphoma
• Prior solid-organ transplantation
• Either of the following: a) received an autologous stem cell transplant \<=3 months before the first dose of JNJ 75348780, b) prior treatment with allogenic stem cell transplant \<= 6 months before the first dose of JNJ-75348780, or has evidence of graft versus host disease that requires immunosuppressant therapy
• Prior chemotherapy, targeted therapy, immunotherapy or radiotherapy (with the exclusion of palliative radiation to limited sites that do not interfere with response assessment based on a sufficient number of other sites), within 2 weeks before the first administration of study drug. For investigational agents where the half-life is known, there should be a treatment-free window of at least 2 weeks or 5 half-lives, whichever is longer. For investigational agents with long half-lives a wash-out of 4 weeks is acceptable. Participants who received prior treatment with anti-CD20 \* anti-CD3 bispecific therapy will be excluded until a dedicated cohort(s) is opened as determined by the SET
• Active autoimmune disease that requires systemic immunosuppressive medications (example, chronic corticosteroid, methotrexate, or tacrolimus)
• History of malignancy (other than the disease under study in the cohort to which the participant is assigned) within 1 year prior to the first administration of study drug. Exceptions are squamous and basal cell carcinomas of the skin and carcinoma in situ of the cervix, or malignancy which in the opinion of the investigator, with concurrence with the sponsor's medical monitor, is considered cured with minimal risk of recurrence within 1 year before the first dose of study drug. Concomitant malignancies that are unlikely to progress and/or preclude evaluation of study endpoints may be allowed after discussion with the Study Responsible Physician