Mosunetuzumab With Lenalidomide Augmentation as First-line Therapy for Follicular and Marginal Zone Lymphoma

BrUOG-401 is a prospective, single-arm, phase 2 trial of first-line therapy in adult patients with previously untreated FL or MZL. All patients will be assigned the same initial treatment plan, modified by interim response assessment (IRA) after Cycle 4. All patients will start treatment with four 21-day cycles (C1-4) of mosunetuzumab alone (using step-up dosing during C1), followed by IRA. Patients who achieve CR at IRA will continue with additional 4 cycles (C5-8) of mosunetuzumab. Patients who achieve PR at IRA will receive mosunetuzumab with lenalidomide augmentation during C5-8. Primary response assessment (PRA) will occur after C8. Patients who remain in PR at PRA will continue for additional 4 cycles (extended augmentation).