A Safety and Efficacy Study of Ibrutinib in Pediatric and Young Adult Participants With Relapsed or Refractory Mature B-cell Non-Hodgkin Lymphoma

The purpose of this study is to confirm that the pharmacokinetics of ibrutinib in pediatric participants is consistent with that in adults (part 1) and to assess efficacy (event-free survival \[EFS\]) of ibrutinib in combination with rituximab, ifosfamide, carboplatin, and etoposide (RICE) or rituximab, vincristine, ifosfamide, carboplatin, and idarubicin (RVICI) background therapy compared to RICE or RVICI background therapy alone (part 2).

This is a Phase 3, randomized (study medication assigned to participants by chance), open-label (identity of study drug will be known to participant and study staff), controlled study which consists of two parts: Part 1 and Part 2. The Part 1 is a pharmacokinetic run-in part, which will be conducted before starting the randomized part (Part 2) of the study and Part 2 is a randomized and open-label study. Part 1 and Part 2 of the study will be conducted in 3 phases: a Pretreatment (Screening) Phase (Up to 14 days before administration of study drug), a Treatment Phase, and a Posttreatment Phase. The Treatment Phase will extend from enrollment (in Part 1) or randomization (in Part 2) until 1 of the following: 1) completion of 3 cycles of therapy, 2) transplantation, if clinically indicated, or 3) progressive disease (PD), whichever comes first. The Posttreatment Phase will continue until death, loss to follow up, consent withdrawal, or study end, whichever occurs first. The end of study is defined as when approximately 60 event-free survival (EFS) events have occurred in Part 2 (death, disease progression, or lack of complete response \[CR\] or partial response \[PR\] after 3 cycles of treatment based on blinded independent event review), or the sponsor terminates the study, whichever comes first. Participants in Part 1 will be 1 to less than (\<) 18 years old. Participants in Part 2 will be 1 to 30 years old. Participants will be primarily evaluated for pharmacokinetics in part 1 and efficacy (EFS) of ibrutinib in combination with RICE or RVICI background therapy compared to RICE or RVICI background therapy alone in part 2. Participants' safety will be monitored throughout the study.

Eligibility Criteria:
Inclusion Criteria:

* Participants with 1 to less than (\<) 18 years of age (Part 1 only), or 1 to 30 years of age, inclusive, if initial diagnosis of mature B-cell non-Hodgkin lymphoma (NHL) occurred at \<18 years of age (Part 2 only)
* Participants must be in first recurrence and have received only one prior line of therapy or have disease that is primarily refractory to conventional therapy
* Participants must have at least 1 of the following: 1 site of measurable disease greater than (\>) 1 centimeter (cm) in the longest diameter and \>1 cm in the shortest diameter by radiological imaging; bone marrow involvement; cerebrospinal fluid with blasts present
* Participants with lansky-Karnofsky score of greater than or equal to (\>=) 50
* Adolescent women/young women of childbearing potential must have a negative highly sensitive serum or urine beta-human chorionic gonadotropin (beta-hCG) pregnancy test at Screening before enrollment/randomization. Adolescent/young women who are pregnant or breastfeeding are ineligible for this study

Exclusion Criteria:

* Participants with ongoing anticoagulation treatment with warfarin or equivalent vitamin K antagonists (example phenprocoumon), or ongoing treatment with agents known to be strong CYP3A4/5 inhibitors, or has taken any disallowed therapies as noted in Section 8.2, Prohibited Medications, before the planned first dose of study drug
* Participants with inherited or acquired bleeding disorders
* Participants with clinically significant arrhythmias, complex congenital heart disease, or left ventricular ejection fraction (LVEF) \<50 percent (%) or shortening fraction (SF) \<=28%
* Participants with known history of human immunodeficiency virus (HIV) or active Hepatitis B or C virus
* Participants with any condition that could interfere with the absorption or metabolism of ibrutinib including malabsorption syndrome, disease significantly affecting gastrointestinal function, or resection of the stomach or small bowel
* Participants with known allergies, hypersensitivity, or intolerance to ibrutinib or its excipients (refer to Investigator's Brochure)
* A diagnosis of post-transplant lymphoproliferative disease (PTLD)
* Participants who are within 6 months of an allogeneic bone marrow transplant
* Participants who have had prior exposure to ibrutinib