A Study of JNJ-88998377 for Relapsed/Refractory B-cell Non-Hodgkin's Lymphoma

Inclusion Criteria:

• Participants have histologically or cytologically confirmed B-cell non-Hodgkin'sLymphoma (NHL) according to the 2022 World Health Organization (WHO) classificationwith relapsed or refractory disease

• Participants have measurable disease or meet all requirements for adequate responseassessment as defined by the appropriate disease response criteria at screening

• Participants have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

• Participants have a life expectancy of greater than or equal to (>=) 12 weeks

• Be willing and able to adhere to the lifestyle restrictions specified in theprotocol

Exclusion Criteria:

• Participant with active or prior history of B-cell NHL involving the central nervoussystem (CNS) and leptomeningeal involvement

• History of malignancy (other than the disease under study in the cohort to which theparticipant is assigned) within 1 year prior to the first administration of studytreatment.

• For Part A and B: Participant having known allergies, hypersensitivity, orintolerance to the excipients of JNJ-88998377

• Participant had major surgery or had significant traumatic injury within 30 daysbefore first dose of study treatment or has not recovered from surgery and must nothave major surgery planned during the time the participant is receiving studytreatment

• Participant received an autologous stem cell transplant less than or equal to (<=) 3months before the first dose of study treatment