INCB050465 in Combination With Rituximab, Bendamustine and Rituximab, or Ibrutinib in Participants With Previously Treated B-Cell Lymphoma (CITADEL-112)

Inclusion Criteria: * Men and women, aged 18 years or older on the day of signing the Informed Consent Form (ICF). * Histologically confirmed indolent/aggressive DLBCL, FL, MZL, or MCL. * Participants with DLBCL, MZL or MCL must have received at least 1 prior line of systemic therapy with documented progression or documented failure to achieve CR or PR after the most recent systemic treatment regimen. * Participants with FL must have received at least 2 prior lines of systemic therapy with documented progression or documented failure to achieve CR or PR after the most recent systemic treatment regimen. * Ineligible for stem cell transplant. * Participants with DLBCL must have failed or refused stem cell transplantation or failed first-line salvage therapy if ineligible for transplantation. * Must be willing to undergo an incisional or excisional lymph node or tissue biopsy or to provide a lymph node or tissue biopsy from the most recent available archival tissue. * Life expectancy of \> 3 months. * Eastern Cooperative Oncology Group (ECOG) performance status score of 0 to 2 (see Appendix D). * Willingness to avoid pregnancy or fathering a child. * Ability to comprehend and willingness to sign an ICF Exclusion Criteria: * Evidence of transformed non-Hodgkin lymphoma histologies (with the exception of FL). * Histologically confirmed rare non-Hodgkin B-cell subtypes. * History of or central nervous system lymphoma (either primary or metastatic) or leptomeningeal disease. * Prior treatment with idelalisib, other selective PI3Kδ inhibitors, or a pan-PI3K inhibitor. * For participants to be treated with bendamustine (Treatment B), prior treatment with bendamustine (within 12 months of the start of study treatment). Participants with prior bendamustine treatment (\> 12 months before the start of study treatment) are eligible if they meet the following criteria: * Did not discontinue because of tolerability concerns. * Achieved either partial response (PR) or complete response (CR) to the bendamustine regimen of at least 12 months in duration before relapse/progression. * Experienced progression following a regimen containing an alkylating agent. * For participants to be treated with ibrutinib (Treatment C), prior treatment with a Bruton's tyrosine kinase (BTK) inhibitor. * Allogeneic stem cell transplant within the last 6 months or autologous stem cell transplant within the last 3 months before the date of the first dose of study treatment. * Active graft-versus-host disease following allogeneic transplant. * Hepatitis B virus (HBV) or hepatitis C virus (HCV) infection.