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

Inclusion Criteria:

* No prior treatment for diffuse B-cell lymphoma (DLBCL)
* Histologically-confirmed non-germinal center B-cell subtype DLBCL
* Stage II (not candidates for local x-ray therapy), III, or IV disease by the Ann Arbor Classification
* At least 1 measurable site of disease according to Revised Response Criteria for Malignant Lymphoma
* Revised International Prognostic Index score of \>=1
* Eastern Cooperative Oncology Group performance status grade of 0, 1, or 2
* Hematology and biochemical laboratory values within protocol-defined parameters prior to random assignment and at baseline
* Left ventricular ejection fraction within institutional normal limits, as determined by echocardiography or multiple uptake gated acquisition (MUGA) scan
* Agrees to protocol-defined use of effective contraception (for women, these restrictions apply for 12 months after the last dose of rituximab or 1 month after the last dose of study drug, whichever is later; for men, these restrictions apply for 12 months after the last dose of rituximab or 3 months after the last dose of study drug, whichever is later)
* Men must agree to not donate sperm during and after the study for 12 months after the last dose of rituximab or 3 months after the last dose of study drug, whichever is later
* Women of childbearing potential must have a negative serum or urine pregnancy test at screening

Exclusion Criteria:

* Major surgery within 4 weeks of random assignment
* Known central nervous system or primary mediastinal lymphoma
* Prior history of indolent lymphoma
* Diagnosed or treated for malignancy other than DLBCL, except: malignancy treated with curative intent and with no known active disease present for \>=3 years before random assignment; adequately treated non-melanoma skin cancer or lentigo maligna without evidence of disease; adequately treated carcinoma in situ without evidence of disease
* History of stroke or intracranial hemorrhage within 6 months prior to random assignment
* Requires anticoagulation with warfarin or equivalent vitamin K antagonists
* Requires treatment with strong CYP3A inhibitors
* Prior anthracycline use \>=150 mg/m2
* Clinically significant cardiovascular disease such as uncontrolled or symptomatic arrhythmias, congestive heart failure, or myocardial infarction within 6 months of screening, or any Class 3 (moderate) or Class 4 (severe) cardiac disease as defined by the New York Heart Association Functional Classification
* Known history of human immunodeficiency virus or active hepatitis C virus or active hepatitis B virus infection or any uncontrolled active systemic infection requiring intravenous antibiotics
* Women who are pregnant or breastfeeding
* Any life-threatening illness, medical condition, or organ system dysfunction which, in the investigator's opinion, could compromise the patient's safety, interfere with the absorption or metabolism of ibrutinib capsules, or put the study outcomes at undue risk