A Study of the Bruton's Tyrosine Kinase Inhibitor, PCI-32765 (Ibrutinib), in Combination With Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone in Patients With Newly Diagnosed Non-Germinal Center B-Cell Subtype of Diffuse Large B-Cell Lymphoma

This is a randomized (individuals assigned to study treatment by chance), double-blind (individuals and study personnel will not know the identity of study treatments), placebo (an inactive substance that is compared with a drug to test whether the drug has a real effect in a clinical trial)-controlled study to compare the efficacy and safety of ibrutinib in combination with R-CHOP versus R-CHOP alone in adult patients newly diagnosed non-GCB DLBCL selected by IHC or newly diagnosed patients with ABC subtype of DLBCL identified by GEP or both populations. The study will include screening, active treatment, and posttreatment follow-up phases. The study will end when 50% of participants have died or 5 years after the last participant is randomized or the sponsor terminates the study, whichever occurs first. Approximately 800 participants will be randomly assigned in a 1:1 ratio to receive either placebo+R-CHOP (treatment arm A) or ibrutinib+R-CHOP (treatment arm B). All participants will receive R-CHOP as background therapy for 6 or 8 cycles (21 days per cycle) prespecified according to local practice. After 4 treatment cycles, an interim response assessment will be performed to evaluate disease progression for each participant. Participants with progressive disease or relapsed disease after complete response will be discontinued from treatment. Participants who discontinue R-CHOP without disease progression will continue study drug (placebo or ibrutinib) until 6 or 8 cycles are completed, disease progression, or unacceptable toxicity, whichever occurs first. After completion of study drug, participants will undergo assessment of tumor response based on the Revised Response Criteria for Malignant Lymphoma. Participants with documented residual disease upon completion of at least 6 cycles of R-CHOP therapy are considered eligible to initiate subsequent antilymphoma therapy. Serial pharmacokinetic samples will be collected before and after dosing, and safety will be monitored throughout the study.