An Open-Label Phase lB/II Study of Glofitamab and Atezolizumab or Polatuzumab Vedotin in Adult Patients With Relapsed/Refractory B-Cell Non-Hodgkin's Lymphoma

Glofitamab will be administered through IV infusion every 3 weeks (Q3W) beginning Cycle 1, Day 1, for up to 17 cycles (Cycle = 21 days). Step-up dosing, in which an initial lower dose will be followed by a higher dose 1 week later, will be considered for the initial treatment phase and for Cycle 9 of the re-treatment phase.

Atezolizumab will be administered in combination with Glofitamab through IV infusion Q3W from Cycle 2, Day 1, for up to 16 cycles (Cycle = 21 days).

Obinutuzumab will be administered once, through IV infusion, at a fixed dose 7 days before the first dose of Glofitamab.

Tocilizumab will be administered as necessary to treat cytokine release syndrome (CRS).

Polatuzumab vedotin will be administered in combination with Glofitamab (on different days) Q3W from Cycle 1, Day 2, for up to 12 cycles (Cycle = 21 days).

Participants will receive 89Zr-Df-IAB22M2C (Cycle 1 only) prior to obinutuzumab pre-treatment and again on Day 10 after dosing with glofitamab, followed by PET/CT.