Rituximab Plus Venetoclax in Front Line Marginal Zone Lymphoma

This is a phase II study of rituximab plus venetoclax in participants with MZL who have not had prior chemotherapy. The purpose of this study is to see if the combination of rituximab and venetoclax is effective in treating Marginal Zone Lymphoma. The U.S. Food and Drug Administration (FDA) has not approved venetoclax for MZL but it has been approved for other uses. The FDA has approved rituximab as a treatment option for MZL. The research study procedures include screening for eligibility, study treatment visits, Computerized Tomography (CT) scans, Magnetic Resonance Imaging (MRI) scans, Positron Emission Tomography (PET) scans, blood tests, bone marrow and tumor biopsies, and electrocardiograms. Participants will receive study treatment for up to 24 months and will be followed for 1 year after discontinuation of the study drugs. It is expected that about 33 people will take part in this research study. Abbvie, Inc. is funding this research study by providing venetoclax.