This phase I study is trying to understand the appropriate dose level and effectiveness of a new cancer drug (RO7443904) when administered with a targeted therapy (Glofitamab) in people with relapsed or refractory B-cell non-Hodgkin's lymphoma, after they have received a different targeted therapy (obinutuzumab) as pre-treatmentAn Open-Label, Phase 1 Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of RO7443904 in Combination With Glofitamab in Participants With Relapsed/Refractory B-Cell Non-Hodgkin's Lymphoma

Exclusion

• Circulating lymphoma cells, defined by out-of-range (high) absolute lymphocyte count (ALC) or the presence of abnormal cells in the peripheral blood signifying circulating lymphoma cells
• Participants with known acute bacterial, viral, or fungal infection 72 hours prior to glofitamab infusion
• Participants with known active infection or reactivation of a latent infection
• Pregnant, breastfeeding, or intending to become pregnant during the study
• Prior treatment with systemic immunotherapeutic agents
• History of treatment-emergent, immune-related adverse events (AEs) associated with prior immunotherapeutic agents
• Persistent AEs from prior anti-cancer therapy Grade >=1
• Treatment with standard radiotherapy, any chemotherapeutic agent, or treatment with any other investigational or approved anti-cancer agent
• Prior solid organ transplantation
• Prior allogeneic stem cell transplant (SCT)
• Autologous SCT within 100 days prior to obinutuzumab infusion
• Autoimmune disease in active phase or exacerbation/flare within at least 6 months of enrollment
• History of immune deficiency disease that increases the risk of infection
• History of contraindication and/or severe allergic or anaphylactic reactions to monoclonal antibody therapy and/or prophylactic drugs used for cytokine release syndrome (CRS) and tumor lysis syndrome (TLS)
• History of confirmed progressive multifocal leukoencephalopathy
• Current or past history of central nervous system (CNS) lymphoma or CNS disease
• Evidence of significant, uncontrolled concomitant diseases that could affect compliance with the protocol or interpretation of results
• Major surgery or significant traumatic injury <28 days prior to the GpT infusion or anticipation of the need for major surgery during study treatment
• Participants with another invasive malignancy in the last 2 years
• Significant cardiovascular disease
• Administration of a live, attenuated vaccine within 4 weeks before GpT infusion or anticipation that such a live attenuated vaccine will be required during the study
• Received systemic immunosuppressive medications for reasons other than anticancer therapy within the last 6 months of enrollment with the exception of corticosteroid treatment <= 25 mg/day prednisone or equivalent
• History of illicit drug or alcohol abuse within 12 months prior to screening, in the Investigator's judgment
• Any other diseases, metabolic dysfunction, physical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that would contraindicate the use of an investigational drug