FDA Approves Subcutaneous Mosunetuzumab in R/R Follicular Lymphoma

The FDA has granted accelerated approval to a subcutaneous formulation of mosunetuzumab (Lunsumio VELO) for adults with relapsed/refractory follicular lymphoma following 2 or more prior lines of systemic treatment, according to a press release from the developer, Roche.¹

Full approval for subcutaneous mosunetuzumab may be dependent on verification of its clinical benefit in a confirmatory trial.

Supporting data for the approval came from the primary analysis of the phase 1/2 GO29781 trial (NCT02500407), in which investigators assessed the efficacy, safety, and pharmacokinetics of mosunetuzumab administered intravenously or subcutaneously. Topline data showed an objective response rate (ORR) of 75% (95% CI, 64%-83%) and a complete response (CR) rate of 59% (95% CI, 48%-69%) with the subcutaneous formulation of mosunetuzumab. Additionally, the median duration of response (DOR) was 22.4 months (95% CI, 16.8-22.8).

Safety data revealed that the most common adverse effects (AEs) associated with subcutaneous mosunetuzumab included injection site reactions, fatigue, rash, cytokine release syndrome (CRS), COVID-19 infection, diarrhea, and musculoskeletal pain. Investigators noted CRS events in 30% of patients, which generally occurred within the first cycle of treatment and resolved following a median of 2 days (range, 1-15).

"This approval is a significant step in broadening access to effective treatments for people living with follicular lymphoma. With its manageable [CRS] profile and reduced administration time, [subcutaneous mosunetuzumab] enables oncologists to deliver advanced care in community practice settings," Ian Flinn, MD, PhD, of Tennessee Oncology and One Oncology, noted in the press release.¹

The subcutaneous formulation of mosunetuzumab can be administered as an approximately 1-minute injection compared with 2 to 4 hours via intravenous treatment. Like its intravenous formulation, subcutaneous mosunetuzumab can be given in the outpatient setting as a fixed-duration therapy for a defined period.

In November 2025, the European Commission approved subcutaneous mosunetuzumab as a treatment for previously treated relapsed/refractory follicular lymphoma.² Supporting data for the approval came from the GO29781 study.

"Since follicular lymphoma often requires lifelong management, reducing the burden of care for these individuals is of paramount importance," Levi Garraway, MD, PhD, chief medical officer and Head of Global Product Development at Roche, stated in the press release.¹ "With this FDA approval, treatment can now be administered in just 1 minute, which significantly reduces the time patients spend in the clinic and helps to align care with their individual needs and preferences."

References

1. FDA approves Roche’s Lunsumio VELO™ for subcutaneous use in relapsed or refractory follicular lymphoma. News release. Roche. December 22, 2025. Accessed December 22, 2025. https://tinyurl.com/mnp3wsdt
2. European Commission approves Roche’s Lunsumio subcutaneous for relapsed or refractory follicular lymphoma. News release. Roche. November 18, 2025. Accessed December 22, 2025. https://tinyurl.com/2pe8r535