Mogamulizumab and Pembrolizumab in Treating Patients With Relapsed or Refractory Diffuse Large B Cell Lymphoma

PRIMARY OBJECTIVES: I. To determine the maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D) of KW-0761 (mogamulizumab) when administered in combination with MK-3475 (pembrolizumab) in patients with relapsed, refractory diffuse large B-cell lymphoma. (Phase I) II. To assess the safety and tolerability of KW-0761 (mogamulizumab) when administered in combination with MK-3475 (pembrolizumab) in patients with relapsed, refractory diffuse large B-cell lymphoma. (Phase I) III. To assess the progression-free survival of KW-0761 (mogamulizumab) when administered in combination with MK-3475 (pembrolizumab) compared to MK-3475 (pembrolizumab) alone in patients with relapsed and refractory diffuse large B-cell lymphomas. (Phase II) SECONDARY OBJECTIVES: I. To observe and record anti-tumor activity. (Phase I) II. To assess the overall response rate, complete response rate, partial response rate, duration of response of KW-0761 (mogamulizumab) and MK-3475 (pembrolizumab) compared to MK-3475 (pembrolizumab) alone in patients with relapsed and refractory diffuse large B-cell lymphomas. (Phase II) EXPLORATORY OBJECTIVES: I. To determine whether the progression-free survival of KW-0761 (mogamulizumab) and MK-3475 (pembrolizumab) when administered to patients with relapsed and refractory diffuse large B-cell lymphomas differs based on the presence or absence of mutations in B2M or CD58 or amplifications in PD-L1. II. To determine whether the progression-free survival of KW-0761 (mogamulizumab) and MK-3475 (pembrolizumab) when administered to patients with relapsed and refractory diffuse large B-cell lymphomas differs based on changes in CD8 T-cell, natural killer (NK) cell, and FoxP3+ regulatory T cell (Treg) prevalence in response to therapy as measured by immunohistochemistry. III. To determine whether KW-0761 (mogamulizumab) and MK-3475 (pembrolizumab) alters the prevalence of peripheral blood CCR4+/FoxP3+ regulatory T-cells as well as effector CD4 and CD8 T-cells by multi-parametric flow cytometry. OUTLINE: This is a phase I, dose-escalation study of mogamulizumab followed by a phase II study. Patients are randomized to 1 of 2 arms. ARM I: Patients receive pembrolizumab intravenously (IV) over 30 minutes on day 1 and mogamulizumab IV over 60 minutes on days 1, 8, and 15 of cycle 1, then day 1 of subsequent courses. Cycles repeat every 21 days for up to 2 years in the absence of disease progression or unacceptable toxicity. ARM II: Patients receive pembrolizumab IV over 30 minutes on day 1. Cycles repeat every 21 days for up to 2 years in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up for 4 weeks.