A Study of Parsaclisib, a PI3Kδ Inhibitor, in Combination With Bendamustine and Rituximab in Patients With Newly Diagnosed Mantle Cell Lymphoma

Inclusion Criteria: * Male and female participants aged 18 years or older. (Japan aged 20 years or older.) * Have received no previous systemic anti-lymphoma therapies. * Pathologically confirmed MCL by local laboratory. * Histologically confirmed CD20 expression (by flow cytometry or immunohistochemistry) of the MCL cells as assessed by pathology. * Ineligible for high-dose chemotherapy and autologous stem cell transplantation. * Radiographically (CT, MRI) measurable lymphadenopathy per the Lugano criteria for response assessment (Cheson et al 2014). * ECOG PS of 0 to 2. * Willingness to avoid pregnancy or fathering children. Exclusion Criteria: * Presence of any lymphoma other than MCL. * Presence of CNS lymphoma (either primary or secondary) or leptomeningeal disease. * Requires treatment with potent inducers and inhibitors of CYP3A4 * Inadequate organ functions including hematopoiesis, liver, and kidney significant concurrent, uncontrolled medical condition, including, but not limited to, renal, hepatic, hematological, GI, endocrine, pulmonary, neurological, cerebral, or psychiatric disease. * History of other malignancy within 2 years of study entry. * Known HIV infection, HBV or HCV. * HBV or HCV infection: Participants positive for HBsAg or anti-HBc will be eligible if they are negative for HBV-DNA; these participants must receive prophylactic antiviral therapy. Participant's positive for HCV antibody will be eligible if they are negative for HCV-RNA. * Clinically s…