Three-year follow-up of a multinational phase 1-2 trial of mosunetuzumab for relapsed or refractory follicular lymphoma after ≥ 2 prior therapies

Mosunetuzumab is a CD20xCD3 T-cell engaging bispecific antibody that can redirect T cells to eliminate malignant B cells. A multinational phase 1-2 trial evaluated mosunetuzumab for relapsed of refractory follicular lymphoma after two or more prior therapies. Three-year follow-up results have now been published. Complete response rate and objective response rate were 60.0% (95% CI 49.1-70.2) and 77.8% (67.8-85.9), respectively, with median duration of response 35.9 months (20.7-NE). Median progression-free survival was 24.0 months (95% CI 12.0-NE) and median overall survival was not reached, with a 36-months OS rate of 82.4% (73.8-91.0). No new cytokine release syndrome events or fatal, serious, or grade ≥ 3 adverse events were reported. The authors conclude that mosunetuzumab demonstrated high response rates, durable remissions, and manageable safety among patients who received two or more previous lines of therapy for follicular lymphoma.