Tazemetostat and Mosunetuzumab in Untreated Follicular Lymphoma

The goal of this study is to learn about the safety and effectiveness of the combination of tazemetostat pills in combination with mosunetuzumab injections for people with follicular lymphoma who haven't received treatment before. The investigators hypothesize that tazemetostat with mosunetuzumab has the potential to increase the efficacy of the product without compromising the safety. Tazemetostat is a drug that inhibits EZH2, an enzyme known to drive the development of B-cell lymphomas, and inhibiting it appears to have many effects that slow down lymphoma growth and enhance the immune system's ability to fight it. Tazemetostat is FDA-approved in previously treated follicular lymphoma and currently undergoing study in other lymphomas. Mosunetuzumab is a bispecific antibody therapy that is a therapeutic strategy that uses the immune system to fight lymphoma, called immunotherapy. Bispecific antibodies have two ends: one attaches to T cells in the immune system and the other attaches to lymphoma cells, helping guide our immune system to attack the cancer. Mosunetuzumab has been studied in follicular lymphoma that has previously been treated, with positive results. Mosunetuzumab is approved by the FDA to be given intravenously (directly into a vein) but is not yet approved by the FDA is not yet approved as an injection under the skin, which is how it is given in this study. They have not yet been studied in combination.