SOHO State of the Art Updates and Next Questions | Latest Advances in the Management of Primary Mediastinal B-Cell Lymphoma.

Abstract

Primary mediastinal B-cell lymphoma (PMBCL) is recognized as a distinct clinicopathologic entity that predominantly affects adolescents and young adults (AYA) and is more common in females. Although PMBCL was previously considered to be a subtype of diffuse large B-cell lymphoma, the clinical, histological, and biological characteristics overlap significantly with those of nodular-sclerosing Hodgkin lymphoma (NS-HL). Over recent years, the shared biology of these 2 entities has been highlighted in several studies, and mediastinal gray zone lymphoma, with features intermediate between PMBCL and NS-HL, has been recognized as a unique molecular entity. Although there is a lack of consensus about the optimal therapeutic strategy for patients with newly diagnosed PMCBL, highly curative treatment regimens that obviate the need for mediastinal radiation therapy (RT) are favored by most. Recently, the results from IELSG-37 were presented and demonstrated that patients with a negative PET/CT scan at the completion of treatment do not require consolidative RT. Progress in understanding the biology of PMBCL and its close relationship to NS-HL have helped pave the way for the investigation of novel strategies, including immune checkpoint inhibitors (ICI), CD30-targeting agents and adoptive T-cell approaches. Currently, a clinic trial is ongoing that is evaluating the role of nivolumab with chemo-immunotherapy for the frontline treatment of PMBCL, after ICI have shown robust responses in patients with relapsed and refractory (R/R) PMBCL. In the R/R setting, studies with anti-CD19 CAR-T-cell therapies and treatments with bispecific antibodies have shown good activity.