Pembrolizumab Monotherapy In Relapsed Or Refractory Primary Mediastinal Large B-Cell Lymphoma (Pmbcl): 3-Year Follow-Up Of The Keynote-170 Study

Introduction: No standard of care exists for patients (pts) with relapsed or refractory primary mediastinal B-cell lymphoma (rrPMBCL). As such, pts typically receive therapies recommended for diffuse large B-cell lymphoma, with poor prognosis. Similar to classical Hodgkin lymphoma, rrPMBCL tumors often overexpress the programmed death 1 (PD-1) ligands, PD-L1 and PD-L2. Data from the first full analysis of the phase 2 KEYNOTE (KN)-170 (NCT02576990) study showed that pembrolizumab provided effective and durable antitumor activity with a manageable safety profile in patients with rrPMBCL. These data led to the FDA approval of pembrolizumab for pts with rrPMBCL after ≥2 prior therapies. In this aggressive malignancy with few salvage options, duration of remission with PD-1 blockade remains a critical question. Here we present data from KN170 with an additional 24 months of follow-up in patients with rrPMBCL.