Ibrutinib improves survival for younger people with diffuse large B-cell lymphoma
New evidence suggests that adding the targeted therapy ibrutinib (Imbruvica) to a standard chemotherapy regimen can improve how long some younger people with a specific form of diffuse large B-cell lymphoma (DLBCL) live. The findings, published November 4, 2021, in Cancer Cell, come from a new analysis by researchers at the National Cancer Institute (NCI), part of the National Institutes of Health, of a previously conducted phase 3 clinical trial.
Initial results from that study, known as the PHOENIX trial, showed that combining ibrutinib with the standard chemotherapy regimen did not help patients with a form of DLBCL called non-GCB DLBCL to live longer overall. However, by analyzing tumor biopsy samples from patients on the trial, NCI researchers and their collaborators have now shown that younger patients with specific genetic subtypes of non-GCB DLBCL, called MCD and N1, had an exceptional response to the treatment combination, with all such patients alive without disease three years after diagnosis.
“People thought the trial didn’t work,” said Louis M. Staudt, M.D., Ph.D., chief of the Lymphoid Malignancies Branch in the Cancer for Cancer Research at NCI. “But there was something interesting going on — if you just considered younger patients under the age of 60, they had a real benefit from ibrutinib, and we now understand why.”
“This new analysis provides a compelling rationale for doctors to consider adding ibrutinib to standard chemotherapy for the initial treatment of younger patients with non-GCB DLBCL,” said Wyndham H. Wilson, M.D., Ph.D., senior investigator in the Lymphoid Malignancies Branch and a co-author of the study.
DLBCL is the most common type of lymphoma, accounting for 40% of lymphoma cases worldwide. This fast-growing cancer affects B cells, a type of white blood cell, and usually starts in the lymph nodes. People with DLBCL are typically treated with a chemotherapy regimen known as R-CHOP that includes cyclophosphamide, doxorubicin, vincristine, prednisone, and the monoclonal antibody rituximab. But R-CHOP is not effective for all people with DLBCL.
In the 2000s, to better understand individual variation in treatment response, researchers analyzed the patterns of gene activity in DLBCL tumors. They discovered that there are three molecular subgroups of DLBCL: germinal center B cell-like (GCB), activated B cell-like (ABC), and unclassified. Researchers later found that these subgroups respond differently to chemotherapy. More recently, researchers showed that the ABC and GCB subgroups can be further divided into seven genetic subtypes that also respond differently to chemotherapy.



