Roche's (SIX: RO, ROP; OTCQX: RHHBY) reported that the Phase III CELESTIMO study of mosunetuzumab (Lunsumio) in combination with lenalidomide met its primary progression-free survival (PFS) endpoint in relapsed or refractory follicular lymphoma.
CELESTIMO is the confirmatory trial required to convert mosunetuzumab's accelerated FDA approval and conditional EU marketing authorization — both held for third-line or later (3L+) follicular lymphoma — to full approval, and to support a new indication covering second-line or later (2L+) disease.
The trial compared mosunetuzumab plus lenalidomide against Roche's own rituximab (MabThera/Rituxan) plus lenalidomide in patients who had received at least one prior line of therapy. Roche described the PFS improvement as statistically significant and clinically meaningful at the interim analysis, though numerical data — hazard ratio, median PFS, and p-value — have not yet been disclosed. Overall survival data were immature at the time of the analysis. The safety profile was consistent with the known profiles of the individual agents, with no new signals identified. Detailed results will be submitted to health authorities and presented at an upcoming medical meeting.
Mosunetuzumab is a CD20×CD3 bispecific antibody that simultaneously engages CD20 on malignant B cells and CD3 on T cells, redirecting the patient's existing T cells to kill the tumor cells. It is administered as a fixed-duration regimen — a meaningful distinction in a disease that typically requires lifelong management — and is available in both intravenous and subcutaneous formulations, with the subcutaneous Lunsumio Velo receiving FDA accelerated approval in December 2025.