ABSTRACT
Previous analyses of the phase 2 KEYNOTE-170 (NCT02576990) study demonstrated effective antitumor activity and acceptable safety of pembrolizumab 200 mg given every 3 weeks for up to 35 cycles (∼2 years) in patients with relapsed/refractory (R/R) primary mediastinal B-cell lymphoma (PMBCL) whose disease progressed after or who were ineligible for autologous stem cell transplantation. The end points included objective response rate (ORR), progression-free survival (PFS), and duration of response (DOR) according to the investigator per 2007 Response Criteria; overall survival (OS); and safety. In this final analysis, median duration of follow-up was 48.7 months (range, 41.2-56.2). The ORR was 41.5% (complete response, 20.8%; partial response, 20.8%). The median DOR was not reached; no patients who achieved a complete response progressed at the data cutoff. The median PFS was 4.3 months; the 4-year PFS rate was 33.0%. The median OS was 22.3 months; the 4-year OS rate was 45.3%. At the data cutoff, 30 patients (56.6%) had any-grade treatment-related adverse events (AEs); the most common were neutropenia, asthenia, and hypothyroidism. Grade 3/4 treatment-related AEs occurred in 22.6% of the patients; no grade 5 AEs occurred. After 4 years of follow-up, pembrolizumab continued to provide durable responses, with promising trends for long-term survival and acceptable safety in R/R PMBCL.
Author Affiliations
1IRCCS Azienda Ospedaliero-Universitaria di Bologna Istituto di Ematologia “Seràgnoli,” Bologna, Italy;2Dipartimento di Scienze Mediche e Chirurgiche, Università di Bologna, Bologna, Italy;3Department of Hemato-Oncology, Hôpital Saint-Louis APHP, Paris, France;4Department of Medical Oncology, Pirogov National Medical Surgical Center, Moscow, Russia;5Department of Hematology and Cellular Therapy, University Hospital, Bordeaux, France;6Department of Lymphoid Malignancies, Maria Sklodowska-Curie National Research Institute of Oncology, European Reference Network, Warsaw, Poland;7Department of Hemato-Oncology, Clinica Alemana de Santiago, Santiago, Chile;8Department of Clinical Hematology, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil;9Department of Hematology, Hospital Universitario de Salamanca, Institute of Biomedical Research of Salamanca, Centro de Investigación Biomédica en Red Cáncer, Salamanca, Spain;10Division of Hematology, The James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, OH;11Department of Hematologic Oncology, Anadolu Medical Center, Gebze, Turkey;12Department of Hematology and Bone Marrow Transplantation Unit, Ankara University School of Medicine, Ankara, Turkey;13Department of Hematology, Hospital Israelita Albert Einstein, São Paulo, Brazil;14Department of Clinical Hematology, Lyon-Sud Hospital Center, Lyon, France;15Department of Hematologic Oncology, Dana-Farber Cancer Institute, Boston, MA;16Department of Medical Oncology, Merck & Co, Inc, Rahway, NJ;
