Recruiting

Phase 2

MosunetuzumabLow Dose Mosunetuzumab for the Treatment of Patients With Indolent B-Cell Lymphoma

Sponsor:

University of Washington

Code:

NCT06442475

Conditions

Ann Arbor Stage II Follicular Lymphoma

Ann Arbor Stage II Marginal Zone Lymphoma

Ann Arbor Stage III Follicular Lymphoma

Ann Arbor Stage III Marginal Zone Lymphoma

Ann Arbor Stage IV Follicular Lymphoma

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Biospecimen Collection

Computed Tomography

Magnetic Resonance Imaging

Mosunetuzumab

Positron Emission Tomography

Study Details

Brief summary:

This phase II trial tests the safety, side effects and effectiveness of mosunetuzumab in treating patients with slow growing (indolent) B-cell lymphoma. Mosunetuzumab is a monoclonal antibody that may interfere with the ability of tumor cells to grow and spread.

Conditions

Ann Arbor Stage II Follicular Lymphoma

Ann Arbor Stage II Marginal Zone Lymphoma

Ann Arbor Stage III Follicular Lymphoma

Ann Arbor Stage III Marginal Zone Lymphoma

Ann Arbor Stage IV Follicular Lymphoma

Study ID

NCT06442475

Start date

Aug 29, 2024

Status verified date

Aug, 2026

Completion date

Feb 12, 2028

Anticipated

Primary completion date

Aug 12, 2027

Anticipated

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

18 years or older at time of signing informed consent
Capable of understanding and providing written informed consent
Histologically confirmed indolent B-cell non-Hodgkin lymphoma with no prior therapy for lymphoma. (Prior peptide-based therapeutic vaccines are allowed.) Eligible histologies include:

Follicular lymphoma (grade 1-2 or 3A)
Marginal zone lymphoma
Ann Arbor stage II-IV disease
No prior therapy for lymphoma
Have low-tumor burden disease, defined by Groupe D'Etude des Lymphomes Folliculaires (GELF) criteria:

Nodal or extranodal tumor mass < 7 cm
Involvement of less than 3 nodal sites with a diameter > 3 cm
No systemic or B symptoms
No splenomegaly > 16 cm by imaging
No local risk of vital organ compression
No pleural or peritoneal serous effusions
No leukemic phase (> 5,0000/ uL circulating lymphocytes)
No significant cytopenias defined as platelets < 100,000/uL, hemoglobin < 10 g/dL, or absolute neutrophil count (ANC) < 1500/ uL
Have measurable nodal disease, including at least 1 disease site measuring at least 1.5 cm in longest dimension on CT or fludeoxyglucose F-18 (FDG)-PET, or a FDG-avid extranodal measurable site measuring at least 1.0 cm in longest dimension. Measurable disease also includes spleen size more than 13 cm in vertical length
Eastern Cooperative Oncology Group (ECOG) performance status of 0-2
Creatinine clearance ≥ 50 mL/min calculated by Cockcroft-Gault equation
Total bilirubin ≤ 1.5 x the upper limit of normal (ULN), except in patients with Gilbert's syndrome who may have a total bilirubin up to ≤ 3 x ULN
Aspartate aminotransferase (AST) ≤ 3 x the ULN
Alanine aminotransferase (ALT) ≤ 3 x the ULN
Gamma glutamyl transferase (GGT) ≤ 3 x the ULN
Negative serum or urine pregnancy test within 7 days of initiating mosunetuzumab for women of childbearing potential, defined as those who have not been surgically sterilized or who have not been free of menses for at least 1 year
Fertile male and woman of childbearing potential must agree to use highly effective contraceptive methods from start of treatment to at least 3 months after the last dose of mosunetuzumab

Exclusion Criteria:

History of severe allergic reaction to monoclonal antibody therapy
History of a second primary malignancy that could affect compliance with the protocol or interpretation of results except with permission of the principal investigator. Malignancies treated curatively or at low-risk of progressing at the judgment of the principal investigator (PI) may be included
Known active and uncontrolled bacterial, viral, fungal, mycobacterial, or other infection at study enrollment
Infection with human immunodeficiency virus (unless viral load is undetectable and CD4 count ≥ 200)
Positive test results for chronic hepatitis B infection (defined as positive hepatitis B surface antigen \[HbBsAg\] serology):

Patients with occult or prior hepatitis B infection (defined as positive total hepatitis B core antibody and negative HBsAg) may be included if hepatitis B virus (HBV) deoxyribonucleic acid (DNA) is undetectable at the time of screening. These patients must be willing to undergo monthly DNA testing and appropriate antiviral therapy as indicated by institutional standards
Autoimmune disease requiring active therapy
History of hemophagocytic lymphohistiocytosis (HLH) or macrophage activation syndrome (MAS)
Evidence of significant concurrent disease or medical condition that could interfere with the conduct of the study, or put the patient at significant risk including, but not limited to, significant cardiovascular disease (e.g., New York Heart Association class III or IV cardiac disease, unstable arrhythmias, or unstable angina) or pulmonary disease (including obstructive pulmonary disease and history of bronchospasm)
Ongoing systemic corticosteroid treatment, with the exception of corticosteroid use for other (non-tumor and non-immunosuppressive) indications up to a maximum of 10 mg/day of prednisone or equivalent
Prior use of any monoclonal antibody within 4 weeks before the first mosunetuzumab administration
Prior solid organ transplantation
Pregnant or breast-feeding women, or intending to become pregnant during the study or within 3 months of the last dose of mosunetuzumab

Study Design

Enrollment

20 participants

Anticipated

Intervention Model

Single group

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Treatment (mosunetuzumab)

Patients receive mosunetuzumab IV over 2-4 hours on days 1, 8, 15 and 22. Patients also undergo blood sample collection and PET/CT on study. Patients may undergo CT and/or MRI as clinically indicated and may undergo collection of oral and/or rectal swabs on study.

Interventions

Biospecimen Collection

Undergo blood, oral, and/or rectal sample collection

Computed Tomography

Undergo PET/CT or CT

Magnetic Resonance Imaging

Undergo MRI

Mosunetuzumab

Given IV

Positron Emission Tomography

Undergo PET/CT

Questionnaire Administration

Ancillary studies

Primary outcome measure

Overall response (OR) [ Time Frame: Up to week 13 ]

Central Contacts and Locations

Central contacts

Ajay Gopal

206-606-2037 agopal@uw.edu

Locations

Fred Hutch/University of Washington Cancer Consortium

Recruiting

Seattle, Washington, United States, 98109

Contacts

Ajay Gopal

206-606-2037 agopal@uw.edu

Principal Investigator:

Ajay Gopal

More Information

Sponsor

University of Washington

Last update posted

Aug 27, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-26. This information was provided to ClinicalTrials.gov by University of Washington on 2026-08-27. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.