Entospletinib and Obinutuzumab in Treating Patients With Relapsed Chronic Lymphocytic Leukemia, Small Lymphocytic Lymphoma, or Non-Hodgkin Lymphoma

This phase I/II trial studies the side effect and best dose of entospletinib when giving together with obinutuzumab and to see how well they work in treating patients with chronic lymphocytic leukemia, small lymphocytic lymphoma, or non-Hodgkin lymphoma that has come back. Entospletinib may stop the growth of cancer cells by blocking some of the enzymes need for cell growth. Monoclonal antibodies, such as obinutuzumab, may interfere with the ability of cancer cells to grow and spread. Giving entospletinib and obinutuzumab together may work better in treating patients with chronic lymphocytic leukemia, small lymphocytic lymphoma, or non-Hodgkin lymphoma.

PRIMARY OBJECTIVES: I. To evaluate the safety and tolerability of entospletinib administered in combination with obinutuzumab in patients with relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and non-Hodgkin lymphoma (NHL), and identify the dose for phase 2 expansion. (Phase I) II. To evaluate the efficacy of entospletinib in combination with obinutuzumab in patients with relapsed or refractory CLL/SLL, as measured by complete response (CR) rate. (Phase II) SECONDARY OBJECTIVES: I. Objective response rate (ORR, defined as complete remission, complete response with incomplete marrow recovery, partial remission and nodular partial response). (Phase II) II. Event free survival defined as the interval between the date of first study treatment and the date of objective signs of disease recurrence, subsequent anti-leukemic therapy, or death, whichever is first reported. (Phase II) III. Safety and tolerability of entospletinib in combination with obinutuzumab by adverse events (AEs). (Phase II) EXPLORATORY OBJECTIVES: I. Peripheral blood B-cell depletion and recovery. II. Pharmacodynamics effects of in vivo administration of entospletinib on NFkappaB activation and expression of anti-apoptotic proteins in CLL cells. III. Association of established biomarkers (chromosomal abnormalities, immunoglobulin heavy chain \[IGHV\] mutational status, p53 mutational status) with response (ORR and event-free survival \[EFS\]) to entospletinib (ENTO) in combination with obinutuzumab in patients with relapsed/refractory CLL. OUTLINE: This is a phase I, dose-escalation study of entospletinib followed by a phase II study. Patients receive entospletinib orally (PO) either once a day (QD) or twice a day (BID) on days -7 to -1 (run-in phase) depending on the assigned dose level. Patients also receive obinutuzumab intravenously (IV) on days 1, 2, 8, and 15 of the first cycle and on day 1 of all subsequent cycles. Treatment with obinutuzumab repeats every 28 days for up to 6 cycles and daily treatment with entospletinib continues every 28 days for up to 12 cycles in the absence of disease progression or unexpected toxicity. After completion of study treatment, patients are followed up every 3 months for 12 months then every 6 months thereafter. In the event of study closure, patients who are receiving study drug at the time of closure will complete an abbreviated End of Treatment (EOT) visit. No additional follow up will occur.