A Dose Escalation Study of Glofitamab (RO7082859) as a Single Agent and in Combination With Obinutuzumab, Administered After a Fixed, Single Pre-treatment Dose of Obinutuzumab in Participants With Relapsed/Refractory B-cell Non-hodgkin's Lymphoma

This is a Phase I/II, multicenter, open-label, dose-escalation study designed to evaluate the efficacy, safety, tolerability and pharmacokinetics (PK) of a novel T-Cell bispecific (TCB), glofitamab, administered by intravenous (IV) infusion as a single agent and in combination with obinutuzumab, following pre-treatment with a one-time, fixed dose of obinutuzumab. This entry-into-human (EIH) study is divided in 3 parts: dose escalation (Parts I and II) and dose expansion (Part III). Single-participant dose-escalation cohorts will be used in Part I, followed by conversion to multiple participant dose-escalation cohorts (Part II), in order to define a tentative maximum tolerated dose (MTD) or optimal biological dose (OBD). The expansion cohorts (Part III) will be initiated when the tentative MTD/OBD is defined, to further evaluate the safety, PK and therapeutic activity of glofitamab.

Inclusion Criteria: * Depending upon study part, a history or status of: 1) a histologically-confirmed hematological malignancy that is expected to express cluster of differentiation (CD)20; 2) relapse after or failure to respond to at least one prior treatment regimen; and 3) no available treatment options that are expected to prolong survival (e.g., standard chemotherapy or autologous stem cell transplant \[ASCT\]) * 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 * Able to provide a tumor tissue pretreatment biopsy at last relapse or during screening from a safely accessible site, per investigator determination, providing the patient has more than one measurable target lesion * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Life expectancy of \>/=12 weeks * AEs from prior anti-cancer therapy must have resolved to Grade less than or equal to (\