Perspectives on chemotherapy for the management of double-hit lymphoma

Double-hit (DHL) and triple-hit lymphomas (THL) have long been among the most clinically aggressive molecular subtypes of diffuse large B-cell lymphomas. In the 2016 revised WHO classification, they represent a new entity called high-grade B-cell lymphoma with rearrangements of MYC and BCL2 and/or BCL6. Unlike most B-cell lymphomas, they have poor response to standard R-CHOP therapy, tend to quickly develop resistance to cytotoxic chemotherapies, and are associated with higher central nervous system (CNS) infiltration. This can lead to increased risk of relapse and worse prognosis. DHL/THL represent a subset of lymphomas with unmet medical need.

The authors present the available data for the current treatment regimens including intensive chemotherapy regimens, hematopoietic stem-cell transplantation (HSCT), and CNS prophylaxis. They also discuss treatment for relapsed disease including targeted therapies.

There is currently no accepted standard of care for DHL/THL. For frontline therapy, we recommend enrollment in a well-designed clinical trial if possible, otherwise DA-EPOCH-R with CNS prophylaxis is a commonly used first-line therapy. The authors recommend close surveillance for patients achieving complete response, but for those who fail to achieve a complete response, then clinical trials, more aggressive salvage chemotherapy regimens, or cellular therapies are usually considered.