A Study of ABT-199 Plus Ibrutinib and Rituximab in Patients With Relapsed/Refractory Diffuse Large B-cell Lymphoma

This is a Phase 1b, single-arm, open-label, single-center study of venetoclax (ABT-199) in combination with ibrutinib and rituximab in Subjects with Relapsed/Refractory DLBCL. The trial consists of a dose-escalation of venetoclax in combination with standard doses of ibrutinib and rituximab. For the dose escalation part of the study, a standard 3+3 design will be utilized. Once the MTD has been established, the dose escalation part will be followed by a dose expansion part in a cohort with a maximum of 24 subjects with DLBCL. The purpose of the dose expansion part is to investigate the efficacy of the combination. Between the dose-escalation and dose-expansion, the maximum number of subjects will be 30. Cycle length will be 28 days. Venetoclax will be administered orally QD (Once Daily), continuously for 24 cycles. Ibrutinib will be administered orally QD, continuously for 24 cycles. Rituximab will be administered IV per institutional standards. weekly X 4 (Cycle 1); once on Day 1 of cycles 2-6 only, then every other cycle until Cycle 24 (total 18 doses of Rituxan from C1D1), Commercially available rituximab IV will be used.