On July 14, 2020, the U.S. Food and Drug Administration (FDA) granted breakthrough therapy designation to mosunetuzumab for the treatment of adult patients with relapsed or refractory (R/R) follicular lymphoma (FL) who have received at least two prior systemic therapies.
Mosunetuzumab is a bispecific antibody targeting CD3, on the surface of T cells, and CD20, on the surface of B cells. This dual targeting redirects T cells to engage B cells, leading to the lysis and elimination of malignant cells.
The breakthrough therapy designation is based on the promising results of the phase I/Ib GO29781trial ( NCT02500407) investigating mosunetuzumab monotherapy and in combination with other agents in patients with R/R non-Hodgkin lymphoma. In the subgroup of patients with R/R FL, mosunetuzumab showed high response rates and durable complete remissions with a tolerable safety profile.