The primary purpose of this study is to determine: the recommended Phase 2 doses (RP2Ds) of JNJ-64264681 and JNJ 67856633 when administered together in participants with B cell non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) (Part A - Dose Escalation); and the safety of the RP2Ds for this combination in different histologies/participant populations (Part B - Cohort Expansion).

Bruton's tyrosine kinase (BTK) is a cytoplasmic tyrosine kinase that plays a critical role in B cell activation via the B cell receptor (BCR) signaling pathway. BTK is important for normal B-cell activation and the pathophysiology of B cell malignancies. A few BTK inhibitors have demonstrated clinical activity in non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL). Non-Hodgkin lymphoma represents a diverse set of diseases, of which more than 60 subtypes have been identified and classified by the world health organization. JNJ-64264681 is a second-generation, orally active, selective, and irreversible covalent inhibitor of BTK and JNJ-67856633 is an orally bioavailable, potent, and selective first in class mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) inhibitor that binds to an allosteric site on MALT1 with a mixed-type mechanism. JNJ-64264681 and JNJ-67856633 inhibit BTK and MALT1, respectively, and both BTK and MALT1 are involved in transmitting the pro-survival BCR signal. The study will consist of Screening Phase (28 days); Treatment Phase (from Cycle 1 Day 1 up to end of treatment, each cycle is a 21-day cycle) and a Follow-up Phase (from end of treatment visit until lost to follow-up, withdrawal of consent, death, 6 months after start of first subsequent antineoplastic therapy, after the clinical cut off (CCO) date participants will be withdrawn from the study 30 days after the last dose of study drugs were administered). The total study duration is estimated at 2 years and 2 months. Safety assessments will include physical examinations, vital signs, electrocardiograms, clinical safety laboratory assessments, eastern cooperative oncology group performance status, echocardiogram, and adverse events monitoring.

Inclusion Criteria:

• Eastern Cooperative Oncology Group (ECOG) performance status grade of 0 or 1
• Cardiac parameters within the following range: corrected QT interval (QTcF) <= 480 milliseconds
• Participants with B cell non-Hodgkin lymphoma (NHL) must have tumor tissue available at baseline as described in the protocol. This is not required for participants with chronic lymphocytic leukemia (CLL)
• Women of childbearing potential must agree to use a barrier method of contraception; use a highly effective preferably user-independent method of contraception; not to donate eggs (ova, oocytes) or freeze them for future use for the purposes of assisted reproduction during the study; not to plan to become pregnant; and not to breast-feed

Exclusion Criteria:

• Part A and select cohorts in Part B: Prior treatment with JNJ 64264681 or JNJ-67856633. Previously discontinued treatment with a Bruton's tyrosine kinase (BTK) or mucosa-associated lymphoid tissue lymphoma translocation protein (MALT) inhibitor other than JNJ 64264681 or JNJ-67856633 due to participant or doctor choice without evidence of progression or intolerable class-related toxicity will be eligible
• Known (active) central nervous system (CNS) involvement
• Received prior solid organ transplantation
• Participant has known allergies, hypersensitivity, or intolerance to JNJ-64264681 or JNJ 67856633 or excipients
• Toxicities from previous anti-cancer therapies that have not resolved to baseline levels, or to Grade less than (<) 2 (except for alopecia [>=Grade 2], vitiligo [Grade 2] and peripheral neuropathy [Grade 1])

The data sharing policy of the Janssen Pharmaceutical Companies of Johnson & Johnson is available at www.janssen.com/clinical-trials/transparency. As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at yoda.yale.edu