Emerging Strategies in Treating Double Hit Lymphomas

A multi-center analysis of the impact of DA-EPOCH-R dose-adjustment on clinical outcomes of patients with double/triple-hit lymphoma

Patients with double- and triple-hit lymphomas (DHL/THL) have inferior outcomes with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), and higher-intensity regimens such as dose-adjusted (DA)-EPOCH-R are standard. Dose-intensification of DA-EPOCH-R is guided by hematologic toxicity, without conclusive benefit for DHL/THL patients. To determine if cumulative doses of DA-EPOCH-R or compliance with dose adjustment impacts survival, we retrospectively evaluated detailed clinical data from 109 adult (age ≥18 years) patients with DHL/THL treated with ≥4 cycles of induction DA-EPOCH-R from 2014 to 2019 at six centers. A comprehensive multivariate analysis was performed. Survival outcomes for the entire cohort were comparable to historical estimates for DHL/THL treated with this regimen (median follow-up 27.9 months). Overall survival (OS) and progression-free survival (PFS) were not significantly associated with cumulative chemotherapy dose, dose escalation, or compliance with dose adjustment. Heterogeneous dosing practices were observed. Prospective investigation is warranted to evaluate the practice of dose adjustment of R-EPOCH for patients with DHL/THL.

Diagnostic Approach for Double-Hit and Triple-Hit Lymphoma Based on Immunophenotypic and Cytogenetic Characteristics of Bone Marrow Specimens

BACKGROUND

High-grade B-cell lymphoma with rearrangements of MYC and BCL2 and/or BCL6 (BCL2/BCL6), also known as double-hit lymphoma (DHL) and/or triple-hit lymphoma (THL), is a new entity of B-cell lymphoma in the 2017 WHO Classification. We retrospectively investigated D/THL and their clinico-laboratory features among cases of large B-cell lymphoma involving the bone marrow (BM), including diffuse large B-cell lymphoma, Burkitt lymphoma, and B-cell lymphomas with medium to large lymphoid cells, by additional FISH analysis of BM aspirates.

METHODS

A total of 111 patients diagnosed with aggressive B-cell lymphomas or B-cell lymphoma involving the BM with medium to large-sized malignant lymphocytes were reviewed from January 2000 to January 2018. Patients with available BM aspirates were evaluated by immunophenotyping by flow cytometry, chromosome, and FISH analysis for MYC and/or BCL2/BCL6 rearrangements.

RESULTS

In total, 23/111 (20.7%) showed MYC rearrangement, and eight (7.2%) were reclassified as D/THL on BM after FISH analysis for MYC and BCL2/BCL6. The detection of CD5(-)/CD10(+) based on flow cytometry was strongly associated with D/THL. A complex karyotype with aberrations related to regions in MYC and BCL2/BCL6 was significantly associated with D/THL. When the MYC FISH results of 28 BM aspirates and formalin-fixed paraffin-embedded tissue specimens were compared, 14% were discrepant.

CONCLUSIONS

Immunophenotypic and cytogenetic characteristics facilitate the diagnosis of D/THL in the cases with BM-involving aggressive B-cell lymphomas.

Current perspectives on the treatment of double hit lymphoma

Introduction: Double hit lymphoma (DHL) represents a new diagnostic category with genetic, immunohistochemical and clinical characteristics intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma. Patients with DHL usually experience poor survival after frontline R-CHOP treatment and require alternative therapies. However, the ideal therapeutic options remain undefined. Areas covered: Traditional therapies for the treatment of DHL are discussed, including intensive induction, hematopoietic stem cell transplantation (HSCT), methotrexate CNS-directed prophylaxis, and radiation therapy. The authors further introduce small-molecule inhibitors targeting myc or bcl-2 signaling pathways, chimeric antigen receptor T-cell therapy, programmed death-1 monoclonal antibody and immunomodulatory drugs as novel approaches. Expert opinion: No standard treatment exists for DHL. At present, DA-EPOCH-R exhibits an upfront induction option. Central nervous system prophylaxis with methotrexate is recommended as part of the induction therapy. For those who do not obtain complete remission, HSCT or clinical trials should be considered. Targeted approaches, especially chimeric antigen receptor T-cell therapies and small-molecule inhibitors targeting myc or bcl-2, exhibit the potential of improving outcomes for patients with DHL. High-throughput sequencing is a promising technique both at diagnosis and relapse, in order to predict outcomes and potential novel therapies.

The use of biologics and small molecules in pregnant patients with rheumatic diseases

INTRODUCTION

Biological agents have radically changed the prognosis of rheumatic patients. Current evidence demonstrates that tight disease control during pregnancy is mandatory to minimize adverse outcome risk. As the new therapeutic tools are pivotal to maintain appropriate disease activity, it is timely to review available evidence about the safety of biologics and small molecules in pregnancy. Areas covered: A comprehensive literature review has been performed, reporting available data about the passage into breast milk, rate of pregnancy loss and fetal malformations, and long-term complications due to in utero exposure to biological agents and small molecules. Expert commentary: Data about the safety of agents against tumor necrosis factor in pregnancy are reassuring. Even rituximab, tocilizumab, belimumab, ustekinumab, secukinumab, and abatacept have not been associated with an increased rate of fetal abnormalities or adverse pregnancy outcome. Experience with small molecules is too small to draw any conclusion. Even if further data are warranted to define the possible long-term effects of in utero biologic exposure on the infant immune system development, it is reasonable to speculate that in the next future the use of biologics during pregnancy will continue to expand, at least when maternal benefit justifies the potential risk to the fetus.

Transformation of double-hit follicular lymphoma to plasmablastic lymphoma: a partial role of MYC gene rearrangement

Follicular lymphoma (FL) is genetically characterized by BCL2/IGH translocation. Some FL cases histologically transform to high-grade lymphoma, and the majority of cases transform to diffuse large B-cell lymphoma. We report herein an unusual FL case that transformed to plasmablastic lymphoma (PBL) with MYC gene rearrangement as early as 12 months after FL diagnosis. IGH/MYC translocation, the most common cytogenetic abnormality seen in de novo PBL, was also detected in the transformed tumor (double-hit lymphoma). The patient became resistant to chemotherapy and died 4 months after transformation. We speculate that the “second hit” of MYC rearrangement played a crucial role in PBL transformation (PBL-T) in this case. Highly specific three-color FISH analysis demonstrated the presence of BCL2/IGH/MYC triple fusion signals on a single chromosome as we expected, but BCL2/IGH and IGH/MYC fusion signals also coexisted in a single nucleus. The PBL-T tumor was genetically heterogeneous, despite being histologically quite homogeneous PBL. Surprisingly, three-color FISH analysis revealed that the preceding FL tumor was also genetically heterogeneous, simultaneously harboring BCL2/IGH, IGH/MYC and BCL2/IGH/MYC fusion signals (i.e. double-hit lymphoma), despite being histologically quite homogeneous FL. This suggests that MYC rearrangement played a partial role in PBL-T. Genetic instability including MYC rearrangement in the preceding FL tumor would contribute to PBL-T and poor outcome in this case. This study will broaden our understanding of the pathogenesis of high-grade transformation of FL and help improve patient outcome.