SOUTH SAN FRANCISCO, Calif. — September 16, 2026
Genentech announced that the Phase III CELESTIMO study of Lunsumio® (mosunetuzumab-axgb) plus lenalidomide met its primary endpoint in patients with relapsed or refractory follicular lymphoma who had received at least one prior line of treatment. The interim analysis demonstrated a statistically significant and clinically meaningful improvement in progression-free survival compared with Rituxan® (rituximab) plus lenalidomide. Overall survival data remained immature at the time of the analysis. The safety profile of the Lunsumio and lenalidomide combination was consistent with the known profiles of the individual medicines, with no new safety signals identified. Genentech plans to submit the data to health authorities and present the findings at an upcoming medical meeting.
Lunsumio Combination Supports Earlier-Line FL Treatment
The CELESTIMO results could support expansion of Lunsumio into earlier lines of follicular lymphoma treatment, building on its existing role in previously treated disease. CELESTIMO is a confirmatory study intended to support conversion of Lunsumio’s accelerated approval and conditional marketing authorization for third-line or later follicular lymphoma to full approval, while also seeking an indication in second-line or later disease. The study compares Lunsumio plus lenalidomide with rituximab plus lenalidomide in patients who have received at least one previous systemic treatment. Follicular lymphoma is the most common indolent form of non-Hodgkin lymphoma and is typically characterized by repeated periods of response and relapse. Genentech is positioning the combination as a potential treatment option earlier in the disease journey while emphasizing its outpatient administration and dosing flexibility.
Outpatient Dosing Expands Lunsumio Development Strategy
Lunsumio is a CD20xCD3 T-cell-engaging bispecific antibody designed to redirect patients’ own T cells toward malignant B cells. The molecule targets CD20 on B cells and CD3 on T cells, activating T-cell-mediated destruction of target cells. Genentech highlights the potential for outpatient treatment and flexibility between intravenous and subcutaneous administration, features intended to reduce disruption to patients’ daily lives. Lunsumio is currently approved for people with third-line or later follicular lymphoma in 60 countries worldwide and has been used to treat more than 3,800 patients. The broader development program includes both follicular lymphoma and diffuse large B-cell lymphoma, with Lunsumio also being evaluated in combination with other therapies, including Polivy in second-line or later DLBCL.
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Genentech Expands Lunsumio Across B-Cell Malignancies
The CELESTIMO milestone strengthens Genentech’s broader strategy to expand Lunsumio across different stages and forms of B-cell non-Hodgkin lymphoma. The company is continuing the Phase III MorningLyte study evaluating Lunsumio-based treatment in first-line follicular lymphoma, extending development beyond relapsed disease. In DLBCL, the U.S. FDA has accepted a supplemental Biologics License Application for Lunsumio in combination with Polivy based on results from the SUNMO study. Together, these programs are designed to establish the role of Lunsumio across multiple treatment settings while building on its existing regulatory and clinical foundation. Positive CELESTIMO results provide an additional development milestone as Genentech seeks to move the Lunsumio-based regimen into earlier follicular lymphoma treatment and broaden the therapeutic options available for patients with B-cell malignancies.
Source: Genentech press release
