A Study to Evaluate the Safety and Efficacy of Mosunetuzumab (BTCT4465A) in Combination With Polatuzumab Vedotin in B-Cell Non-Hodgkin Lymphoma

Key Inclusion Criteria:

ECOG PS of 0, 1, or 2
Histologically confirmed FL, DLBCL, or MCL
Must have received at least one prior systemic treatment regimen containing an anti-CD20-directed therapy for DLBCL or FL
For MCL, participants must have received at least two prior systemic treatment regiments, which include 1) anti-CD20-directed therapy, 2) BTK inhibitor, and 3) anthracycline or bendamustine
Relapsed to prior regimen(s) after having a documented history of response (complete response [CR], CR unconfirmed [CRu], or partial response [PR]) of >/= 6 months in duration from completion of regimen(s); or, refractory to any prior regimen, defined as no response to the prior therapy, or progression within 6 months of completion of the last dose of therapy
Measurable disease, defined as at least one bi-dimensionally measurable nodal lesion, defined as > 1.5 cm in its longest dimension, or at least one bi-dimensionally measurable extranodal lesion, defined as > 1.0 cm in its longest dimension
Adequate hematologic, renal, and hepatic function

Key Exclusion Criteria:

Prior treatment with mosunetuzumab or other CD20-directed bispecific antibodies
Prior treatment with polatuzumab vedotin
Current > Grade 1 peripheral neuropathy
Prior use of any monoclonal antibody, radioimmunoconjugate or antibody-drug conjugate (ADC) within 4 weeks before first dose of study treatment
Treatment with any chemotherapeutic agent, or treatment with any other anti-cancer agent (investigational or otherwise) within 4 weeks or 5 half-lives of the drug, whichever is shorter, prior to first dose of study treatment
Treatment with radiotherapy within 2 weeks prior to the first dose of study treatment
Autologous stem-cell transplantation (SCT) within 100 days prior to first study treatment administration
Prior treatment with chimeric antigen receptor T-cell (CAR-T) therapy within 30 days before first study treatment administration
Prior allogeneic SCT
Prior solid organ transplantation
Known or suspected history of hemophagocytic lymphohistiocytosis (HLH)
Patients with history of confirmed progressive multifocal leukoencephalopathy (PML)
Current or past history of central nervous system (CNS) lymphoma or CNS disease
History of autoimmune disease