Low dose mosunetuzumab treatment for indolent B-cell lymphoma

Low Dose Mosunetuzumab for Indolent B-Cell Lymphoma

Phase 2 Interventional University of Washington · NCT06442475

This study is testing a new low-dose treatment called mosunetuzumab to see if it can help people with indolent B-cell lymphoma by slowing down or stopping the growth of their cancer.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment20 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of Washington Academic / other
Drugs / interventionsmosunetuzumab, prednisone
Locations1 site (Seattle, Washington)
Trial IDNCT06442475 on ClinicalTrials.gov

What this trial studies

This phase II trial evaluates the safety, side effects, and effectiveness of mosunetuzumab, a monoclonal antibody, in treating patients with indolent B-cell lymphoma. Participants will receive the treatment intravenously over a period of 2-4 hours on specified days, along with blood sample collection and imaging studies such as PET/CT scans. The study aims to determine how well the drug interferes with tumor cell growth and spread, with follow-up assessments scheduled for up to five years after treatment completion.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older with histologically confirmed indolent B-cell non-Hodgkin lymphoma at Ann Arbor stages II-IV and no prior therapy for lymphoma.

Not a fit: Patients with aggressive forms of lymphoma or those who have received prior treatment for their condition may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for patients with slow-growing B-cell lymphomas.

How similar studies have performed: Other studies have shown promise with monoclonal antibodies in treating B-cell lymphomas, suggesting a potential for success with this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
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

Where this trial is running

Seattle, Washington

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Ann Arbor Stage II Follicular LymphomaAnn Arbor Stage II Marginal Zone LymphomaAnn Arbor Stage III Follicular LymphomaAnn Arbor Stage III Marginal Zone LymphomaAnn Arbor Stage IV Follicular LymphomaAnn Arbor Stage IV Marginal Zone LymphomaGrade 1 Follicular LymphomaGrade 2 Follicular Lymphoma
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.