Combination of Obinutuzumab and Venetoclax in Relapsed or Refractory DLBCL

The study will have a 6 patient run-in phase to determine safety and to adjust treatment. Once the sixth patient has completed 21 days of treatment, withdrawn due to toxicity, or died, a formal review will be undertaken by the sponsor (AGMT). Enrolment will be halted until review is completed. If one (1) treatment related death is reported or three (3) or more patients experience CTC grade 4 events other than neutropenia, anemia, or thrombocytopenia, the study will be stopped for further recruitment. If the stopping criteria are not met, enrollment will be continued. A futility analysis will be conducted when the first 10 patients have been evaluated for response: If at least 2 patients had an objective response (CR or PR), the study will be continued. The combination treatment will be repeated for up to 3 cycles. The first response assessment (including PET-CT) will be performed after the first cycle of obinutuzumab-venetoclax and patients with at least stable disease (SD) or better will be given another 2 cycles of therapy and then have assessment after a total of 3 cycles. Patients with complete or partial remission (CR, PR) after 3 cycles of therapy will either go on to transplant or receive 9 further cycles of the combination therapy (if transplant ineligible). Patients with progressive disease at any time-point or stable disease after 3 cycles will be taken off study.