Roche’s mosunetuzumab-lenalidomide combination beat rituximab plus lenalidomide on progression-free survival in relapsed or refractory follicular lymphoma, according to top-line Phase III data from the roughly 400-patient CELESTIMO study released Wednesday. The trial hit its primary endpoint with results described as both statistically significant and clinically meaningful, giving Roche the randomized Phase III survival data it has needed to push Lunsumio beyond its current accelerated approval, which the FDA granted in December 2022 based on response rate alone in patients who had received at least two prior lines of therapy.
The CELESTIMO population is broader than Lunsumio’s approved indication: patients needed only one prior line of treatment to enroll, and the comparator arm used rituximab plus lenalidomide, a combination with a long track record in this setting. Beating that regimen on PFS in a randomized trial carries more regulatory weight than the single-arm response data that supported accelerated approval, and Roche will likely use these results to seek conversion to full approval and to expand the label to earlier lines. The question regulators and oncologists will ask is how large the PFS benefit was, a figure Roche has not yet released ahead of a conference presentation.
The competitive context makes the magnitude of that benefit consequential. Epcoritamab in combination with lenalidomide and rituximab received FDA approval in November 2025 for relapsed or refractory follicular lymphoma, meaning bispecific antibody-based regimens are no longer a novel category in this disease. Mosunetuzumab is delivered subcutaneously in a fixed-duration course, a design that differs from some continuous-therapy approaches, but clinicians choosing between bispecific-based combinations will weigh the actual PFS curves, not just the mechanism. A narrow separation from the rituximab-lenalidomide arm would read differently than a substantial one when placed alongside data from competing regimens.
Full results are expected at an upcoming medical meeting. The number that will define how this data moves the field is the hazard ratio for progression-free survival, and that is the figure worth waiting for before drawing conclusions about where mosunetuzumab lands in the treatment sequence.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
