RecruitingPhase 2Drug trialMosunetuzumab in Patients With Newly Diagnosed Extranodal Marginal Zone LymphomaThe purpose of this study is to test a new medication called Mosunetuzumab to see if it can help people with Extranodal Marginal Zone Lymphoma (EMZL). This study will include people who have not yet received any treatment for cancer and whose cancer is in stage I-IV. This study will help doctors understand if Mosunetuzumab improves outcomes in people with EMZL and if it is safe to use.