Aberrant Activation of NF-κB Signalling in Aggressive Lymphoid Malignancies

Lymphoid malignancies frequently harbor genetic mutations leading to aberrant activation of nuclear factor-κB (NF-κB) signaling; in normal cells, this pathway has important roles in the control of cell growth, survival, stress responses, and inflammation. Malignancies with mutations in NF-κB pathway components can derive from all cell stages of mature B-cell development; however, aberrant NF-κB activity is particularly prevalent in aggressive subtypes of non-Hodgkin lymphoma and myeloma. NF-κB activation is mediated by two separate pathways, the canonical and alternative pathway, and five downstream transcription factor subunits. Recent findings implicate a predominant role for distinct NF-κB pathways and subunits in certain lymphoma subtypes and myeloma; findings which are complemented by the realization that individual NF-κB subunits can have unique, non-redundant biological roles in the putative tumor precursor cells, including activated B cells, germinal center B cells and plasma cells. The knowledge gained from these studies may be exploited for the development of therapeutic strategies to inhibit aberrant NF-κB activity at the level of the transcription-factor subunits and their target genes, as global inhibition of the pathway is toxic. Here, we provide an overview on the role of aberrant NF-κB activation in aggressive lymphoid malignancies and discuss the potential importance of individual NF-κB subunits in the pathogenesis of tumor subtypes.

Clinical Impact of the 2016 Update to the WHO Lymphoma Classification

OPINION STATEMENT

The 2016 revision of the WHO classification of lymphoid neoplasms includes new entities along with a clearer definition of provisional and definitive subtypes based on better understanding of the molecular drivers of lymphomas. These changes impact current treatment paradigms and provide a framework for future clinical trials. Additionally, this update recognizes several premalignant or predominantly indolent entities and underscores the importance of avoiding unnecessarily aggressive treatment in the latter subsets.

A Phase II Trial of Bortezomib and Vorinostat in Mantle Cell Lymphoma and Diffuse Large B-cell Lymphoma

BACKGROUND

The proteasome inhibitor bortezomib has demonstrated marked preclinical activity when combined with the histone deacetylase inhibitor vorinostat in leukemia, multiple myeloma, and mantle cell lymphoma (MCL) cells. The present study evaluated the efficacy and safety of the combination in patients with relapsed or refractory MCL and diffuse large B-cell lymphoma (DLBCL).

PATIENTS AND METHODS

The present multicenter, nonrandomized phase II trial used a Simon 2-stage design with 3 cohorts: cohort A, MCL with no previous bortezomib (including untreated MCL); cohort B, MCL with previous bortezomib; and cohort C, relapsed or refractory DLBCL with no previous bortezomib. Vorinostat (400 mg) was administered orally on days 1 to 5 and 8 to 12 before bortezomib (1.3 mg/m2), which was administered intravenously on days 1, 4, 8, and 11 of each 21-day cycle.

RESULTS

For the 65 treated patients (22 in cohort A, 4 in cohort B, and 39 in cohort C), the overall response rate was 31.8%, 0%, and 7.7%, respectively. The median progression-free survival was 7.6 months for cohort A and 1.8 months for cohort C. In cohort A, 7 patients had a partial response (PRs), 5 had stable disease (SD), 7 had progressive disease (PD), 1 was not assessed, and 2 were not evaluable. In cohort B, 2 had SD and 2 had PD. In cohort C, 3 had a PR, 8 had SD, 23 had PD, and 5 were not assessed. Baseline NF-κB activation, measured as nuclear RelA by immunohistochemistry, did not correlate with clinical response.

CONCLUSION

The combination of bortezomib and vorinostat is safe and has modest activity in MCL and limited activity in DLBCL.

Optimizing initial therapy in DLBCL

Diffuse large B-cell lymphoma (DLBCL) is a group of lymphomas comprising heterogeneous molecular and biological subtypes, reflected in a broad range of clinical outcomes. With the standard R-CHOP regimen of cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab administered every 21 days, the treatment failure rate remains unacceptably high in certain DLBCL subsets. Here we review possible avenues for optimizing initial therapy. The role of functional imaging and biological features, such as double-hit lymphomas, defined by the dual translocation of MYC and BCL2, and dual protein-expresser lymphomas, defined by the overexpression of MYC and BCL2, activated B-cell (ABC)-like DLBCL, to better define these high-risk patient subsets, and their use to guide and personalize treatment decisions are discussed. Secondly, the implications of varying dose-intensification of the various agents administered, and the link to imaging are reviewed. Thirdly, the results of the addition of novel drugs to standard R-CHOP will be analyzed, when added at induction or in maintenance. Finally, with CNS relapse in DLBCL representing a major and devastating unmet medical need, an overview and future directions for CNS prophylaxis is presented.

NHL in adolescents and young adults: A unique population

Non-Hodgkin lymphoma (NHL) is a heterogeneous group of lymphoid malignancies with high incidence in adolescents and young adults (AYAs). The most common diseases include diffuse large B-cell lymphoma, anaplastic large cell lymphoma, Burkitt lymphoma, lymphoblastic lymphoma, and primary mediastinal large B-cell lymphoma. In comparison to younger children and adults, AYAs (15-39 years) with NHL present a specific set of challenges including variations in tumor biology, inconsistent treatment, pharmacodynamics, and psychosocial barriers. While survival of AYAs with NHL has improved, cure rates remain suboptimal. Incorporation of novel agents into pediatric-inspired treatment regimens specifically designed for NHL in AYAs has led to improved outcomes. Consideration of AYAs as a distinct population in the diagnosis and treatment of NHL is encouraged.

EBV-positive diffuse large B-cell lymphoma, not otherwise specified: 2018 update on diagnosis, risk-stratification and management

DISEASE OVERVIEW

Epstein Barr virus-positive (EBV+) diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS) is an entity included in the 2016 WHO classification of lymphoid neoplasms. EBV+ DLBCL, NOS, is an aggressive B-cell lymphoma associated with chronic EBV infection, and a poor prognosis with standard chemotherapeutic approaches.

DIAGNOSIS

The diagnosis is made through a careful pathological evaluation. Detection of EBV-encoded RNA is considered standard for diagnosis; however, a clear cutoff for positivity has not been defined. The differential diagnosis includes plasmablastic lymphoma, DLBCL associated with chronic inflammation, primary effusion lymphoma, HHV8+ DLBCL, NOS, and EBV+ mucocutaneuos ulcer.

RISK-STRATIFICATION

The International prognostic index (IPI) and the Oyama score can be used for risk-stratification. The Oyama score includes age >70 years and presence of B symptoms. The expression of CD30 is emerging as a potential adverse, and targetable, prognostic factor.

MANAGEMENT

Patients with EBV+ DLBCL, NOS, should be staged and managed following similar guidelines than patients with EBV-negative DLBCL. EBV+ DLBCL, NOS, however, has a worse prognosis than EBV-negative DLBCL in the era of chemoimmunotherapy. There is an opportunity to study and develop targeted therapy in the management of patients with EBV+ DLBCL, NOS.

Comparison of the algorithms classifying the ABC and GCB subtypes in diffuse large B-cell lymphoma

Different immunohistochemical algorithms for the classification of the activated B-cell (ABC) and germinal center B-cell (GCB) subtypes of diffuse large B-cell lymphoma (DLBCL) are applied in different laboratories. In the present study, 127 patients with DLCBL were investigated, all treated with rituximab and cyclophosphamide, hydroxydaunorubicin, oncovin and prednisone (CHOP) or CHOP-like regimens between April 2004 and December 2010. Multi-tumor tissue microarrays were prepared and were tested according to 4 algorithms: Hans; modified Hans; Choi; and modified Choi. For 39 patients, the flow cytometric quantification of CD19 and CD20 antigen expression was performed and the level of expression presented as molecules of equivalent soluble fluorochrome units. The Choi algorithm was demonstrated to be prognostic for OS and classified patients into the GCB subgroup with an HR of 0.91. No difference in the expression of the CD19 antigen between the ABC and GCB groups was observed, but the ABC subtype exhibited a decreased expression of the CD20 antigen compared with the GCB subtype.

Prognostic value of expression of nuclear factor kappa-B/p65 in non-GCB DLBCL patients

Purpose

We estimated the expression of nuclear factor kappa B/p65 in non-germinal center B-cell-like subtype diffuse large B-cell lymphoma, to investigate its relationship to clinicopathological features, and to further evaluate its prognostic value and clarify its impact on survival.

Results

Among the 49 patients enrolled in this study, 14 (28.6%) had positive p65 expression. The negative p65 group had significantly better survival compared to the positive p65 group in terms of both the 3-year estimated OS (91.2% vs. 39.3%, p = 0.003) and PFS (75.6% vs. 26.5%, p = 0.002). In patients with 4 or more risk factors, p65 was an independent prognostic factor of OS (HR 5.99, 95%CI=1.39-25.75, p=0.016) and PFS (HR 4.01, 95%CI=1.15-14.00, p=0.029).

Materials and Methods

The expression of the NF-κB/p65 protein was deteremined by immunohistochemistry in 49 non-GCB DLBCL. Survival was assessed by the Kaplan–Meier method and Cox multivariate analysis. The median patient follow-up period was 24 months.

Conclusions

The expression of NF-κB/p65 has prognostic value in high risk non-GCB DLBCL, and it is a suitable target for the development of new therapies.

Mantle cell lymphoma in the era of precision medicine-diagnosis, biomarkers and therapeutic agents

Despite advances in the development of clinical agents for treating Mantle Cell Lymphoma (MCL), treatment of MCL remains a challenge due to complexity and frequent relapse associated with MCL. The incorporation of conventional and novel diagnostic approaches such as genomic sequencing have helped improve understanding of the pathogenesis of MCL, and have led to development of specific agents targeting signaling pathways that have recently been shown to be involved in MCL. In this review, we first provide a general overview of MCL and then discuss about the role of biomarkers in the pathogenesis, diagnosis, prognosis, and treatment for MCL. We attempt to discuss major biomarkers for MCL and highlight published and ongoing clinical trials in an effort to evaluate the dominant signaling pathways as drugable targets for treating MCL so as to determine the potential combination of drugs for both untreated and relapse/refractory cases. Our analysis indicates that incorporation of biomarkers is crucial for patient stratification and improve diagnosis and predictability of disease outcome thus help us in designing future precision therapies. The evidence indicates that a combination of conventional chemotherapeutic agents and novel drugs designed to target specific dysregulated signaling pathways can provide the effective therapeutic options for both untreated and relapse/refractory MCL.

Should We Use Cell of Origin and Dual-protein Expression in Treating DLBCL?

Treatment outcomes in diffuse large B-cell lymphoma (DLBCL) following standard R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) therapy is highly variable and dependent on a number of clinical, biologic, and genetic features. The identification of molecular heterogeneity via gene expression profiling dichotomizes patients based on the cell of origin (COO) model into germinal center B-cell-like (GCB) and activated B-cell-like (ABC) subsets, with ABC-DLBCL having a worse outcome. Along with the COO classification, other molecular phenotypes have also been identified, further highlighting the clinical and biologic complexity of this disease. Double-hit lymphomas, with concurrent chromosomal translocations of the MYC and BLC2 genes, or less commonly MYC and BCL6 genes, are associated with an aggressive clinical course and adverse outcomes when treated with R-CHOP. Furthermore, dual overexpression of MYC and BCL2 proteins has emerged as an important adverse prognostic factor, can be present through different mechanisms in both GCB and ABC subsets, and further complicates treatment considerations. Studies investigating the biologic underpinnings of these diverse subtypes have revealed a number of novel targets, which may provide therapeutic benefit. Moving forward, clinical trials focusing on molecular subsets of DLBCL, and incorporating rational targeted agents, will ideally lead to improved outcomes and allow a more personalized treatment approach. This review will focus on emerging data regarding DLBCL management based on either COO or dual overexpression of MYC/BCL2 proteins.

Tailoring front-line therapy in diffuse large B-cell lymphoma: who should we treat differently?

Although there have been significant insights into the biology of diffuse large B-cell lymphoma (DLBCL) over recent years, progress in our therapeutic approach has been disappointing over the same timeframe. This is not for want of trying. In 2017, R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) remains the "gold standard," despite all of our insights into cell-of-origin and other subgroups. We have traditionally used clinical risk factors to tailor our therapies and have tested intensification of chemotherapy with little success. We are now in an era of testing therapies according to the molecular phenotype of the individual's tumor. Many phase 1/2 studies have looked at adding targeted agents to conventional R-CHOP with some promise. The phase 3 data are now starting to emerge. Are we ready yet to modify our standard of care and have we reached an era of precision medicine in DLBCL? The answer to this is "not yet." The exception is perhaps patients with the newly defined World Health Organization category of high-grade B-cell lymphoma with rearrangements of MYC and BCL2 and/or BCL6, the so-called double- and triple-hit lymphomas. In these tumors there has been a move away from R-CHOP to more intensified regimens, however, has not been based upon rigorous prospective evaluation but review of retrospective datasets. This article will review the molecular subgroups of DLBCL, interventional strategies, and the outcomes of these interventions to date.

The evolving role of targeted biological agents in the management of indolent B-cell lymphomas

Improved understanding of the mechanisms of lymphomagenesis has resulted in a surge of development for new targeted agents. An impressive number of biological agents targeting different steps in the pathways of tumor proliferation, survival and apoptosis have become available. The management of patients with indolent non-Hodgkin lymphomas (iNHLs) is rapidly transforming with incorporation of those targeted biological agents into the front-line and relapsed/refractory setting. This review highlights several categories of novel biological agents and will discuss their potential role in the contemporary management of patients with iNHLs.

Maintenance therapy following induction chemoimmunotherapy in patients with diffuse large B-cell lymphoma: current perspective

BACKGROUND

Maintenance therapy has proven efficacy in indolent non-Hodgkin lymphoma (NHL), yet its role in diffuse large B-cell lymphoma (DLBCL) is an area of ongoing investigation. While DLBCL is potentially curable, >30% of patients relapse following front-line therapy and have a poor prognosis, especially those with refractory disease. Maintenance therapy holds promise to maintain response post-induction.

PATIENTS AND METHODS

Keyword searches were carried out in PubMed and congress abstracts of 'diffuse large B-cell lymphoma' and 'maintenance' and focused on phase II/III studies of maintenance following front-line induction.

RESULTS

Although used in indolent forms of NHL, studies of maintenance therapy with rituximab in patients with DLBCL responding to front-line R-CHOP (rituximab/cyclophosphamide/doxorubicin/vincristine/prednisone) have not improved efficacy and are not recommended. Targeted agents enzastaurin and everolimus reported results from the phase III studies PRELUDE and PILLAR-2, respectively, both of which showed no proven maintenance benefit following front-line chemoimmunotherapy induction. Overall, the reported efficacy results with these agents in the maintenance setting do not outweigh the risks. Lenalidomide for maintenance has been reported in three studies. Results from two phase II trials on lenalidomide maintenance revealed positive outcomes in higher-risk patients following induction, resulting in improved progression-free survival in relapsed DLBCL patients who were ineligible for transplantation. First analysis from the phase III REMARC trial showed a significant improvement in progression-free survival for lenalidomide versus placebo, with no difference in overall survival, following front-line R-CHOP induction in elderly patients.

CONCLUSIONS

Based on currently available studies of DLBCL maintenance therapies, initial results in front-line, as well as the relapsed setting, with immunomodulators such as lenalidomide show promise for further research to identify appropriate patients who would most benefit. Overall, this review of maintenance studies underscores the need for additional analyses of patient subtypes, clinical risk status, and molecular profiles, with careful consideration of study end points.

Successful hemihepatectomy following chemotherapy for primary liver lymphoma: case report and review of literature

Non-Hodgkin lymphomas (NHL) comprise a heterogeneous group of B-cell and T-cell neoplasms. Diffuse large B-cell lymphoma (DLBCL), the most common type of NHL, accounts for around 30-40% of NHL cases. However, primary hepatic location of NHLs is rare and constitutes 0.01% of all NHL cases. Due to this rarity and a lack of large randomized trails, it is still unclear what treatment should be used for primary hepatic DLBCLs. In this study, we report of a female patient with primary hepatic DLBCL who was successfully treated with neoadjuvant chemotherapy and surgery. We also shortly review the literature regarding surgical treatments for primary GI tract NHLs. Taking into account our experience and the current literature, surgical treatment with postoperative chemotherapy seems to be a feasible option for patients with focal primary hepatic DLBCLs.

Post-autologous transplant maintenance therapies in lymphoma: current state and future directions

Disease relapse following high-dose chemotherapy and autologous stem cell transplant (ASCT) remains the principal cause of mortality in patients with relapsed or refractory lymphomas. In an effort to prevent post-ASCT relapse, a number of studies have evaluated the role of maintenance therapy with varying success. In diffuse large B-cell lymphoma, studies evaluating maintenance rituximab (MR) following ASCT failed to demonstrate improved outcomes. In follicular lymphoma, MR was associated with an improvement in PFS; however, no overall survival (OS) benefit was noted. Emerging data evaluating MR in mantle cell lymphoma (MCL) have demonstrated improvements in PFS, although a consistent improvement in OS has yet to be demonstrated. Given the aggressive and incurable nature of MCL, it is prudent for practitioners to weigh the risks and benefits of MR in the post-ASCT setting. Similarly, post-ASCT maintenance therapy with brentuximab vedotin in Hodgkin lymphoma, has led to improved PFS and may be considered in those with a high risk of relapse. Ongoing clinical studies evaluating a multitude of novel maintenance therapies are crucial to the efforts of further defining and optimizing the role of post-transplant maintenance therapy in lymphoma.

The potential for chemotherapy-free strategies in mantle cell lymphoma

Mantle cell lymphoma (MCL) may be 1 of the few cancers for which multiple chemotherapy and nonchemotherapy regimens are considered as standard. Despite the significant activity of chemotherapy in the first-line setting and beyond, its limitations are reflected in the relatively poor ultimate outcomes of patients with MCL treated in the real world. Patients with highly proliferative MCL and those with TP53 mutations tend to respond poorly despite intensive cytotoxic therapies. Patients with comorbidities and those who are geographically isolated may not have access to the regimens that may appear most promising in clinical trials. Thoughtfully directed, nonchemotherapy agents might overcome some of the factors associated with a poor prognosis, such at TP53 mutation, and might resolve some of the challenges related to the toxicity and deliverability of standard chemotherapy regimens. Several clinical trials have already demonstrated that combinations of nonchemotherapy plus chemotherapy drugs can impact outcomes, whereas data with nonchemotherapy agents alone or in combination have suggested that some patients might be well suited to treatment without chemotherapy at all. However, challenges including chronic or unexpected toxicities, the rational vs practical development of combinations, and the financial acceptability of new strategies abound. The nonchemotherapy era is here: how it unfolds will depend on how we meet these challenges.

Randomized Phase II Study of R-CHOP With or Without Bortezomib in Previously Untreated Patients With Non-Germinal Center B-Cell-Like Diffuse Large B-Cell Lymphoma

Purpose To evaluate the impact of the addition of bortezomib to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) on outcomes in previously untreated patients with non-germinal center B-cell-like (non-GCB) diffuse large B-cell lymphoma (DLBCL). Patients and Methods After real-time determination of non-GCB DLBCL using the Hans immunohistochemistry algorithm, 206 patients were randomly assigned (1:1; stratified by International Prognostic Index [IPI] score) to six 21-day cycles of standard R-CHOP alone or R-CHOP plus bortezomib 1.3 mg/m² intravenously on days 1 and 4 (VR-CHOP). The primary end point, progression-free survival (PFS), was evaluated in 183 patients with centrally confirmed non-GCB DLBCL who received one or more doses of study drug (91 R-CHOP, 92 VR-CHOP). Results After a median follow-up of 34 months, with 25% (R-CHOP) and 18% (VR-CHOP) of patients having had PFS events, the hazard ratio (HR) for PFS was 0.73 (90% CI, 0.43 to 1.24) with VR-CHOP ( P = .611). Two-year PFS rates were 77.6% with R-CHOP and 82.0% with VR-CHOP; they were 65.1% versus 72.4% in patients with high-intermediate/high IPI (HR, 0.67; 90% CI, 0.34 to 1.29), and 90.0% versus 88.9% (HR, 0.85; 90% CI, 0.35 to 2.10) in patients with low/low-intermediate IPI. Overall response rate with R-CHOP and VR-CHOP was 98% and 96%, respectively. The overall survival HR was 0.75 (90% CI, 0.38 to 1.45); 2-year survival rates were 88.4% and 93.0%, respectively. In the safety population (100 R-CHOP and 101 VR-CHOP patients), grade ≥ 3 adverse events included neutropenia (53% v 49%), thrombocytopenia (13% v 29%), anemia (7% v 15%), leukopenia (26% v 25%), and neuropathy (1% v 5%). Conclusion Outcomes for newly diagnosed, prospectively enrolled patients with non-GCB DLBCL were more favorable than expected with R-CHOP and were not significantly improved by adding bortezomib.

Is now the time for molecular driven therapy for diffuse large B-cell lymphoma?

INTRODUCTION

Recent genetic and molecular discoveries regarding alterations in diffuse large B-cell lymphoma (DLBCL) deeply changed the approach to this lymphoproliferative disorder. Novel additional predictors of outcomes and new therapeutic strategies are being introduced to improve outcomes. Areas covered: This review aims to analyse the recent molecular discoveries in DLBCL, the rationale of novel molecular driven treatments and their impact on DLBCL prognosis, especially in ABC-DLBCL and High Grade B Cell Lymphoma. Pre-clinical and clinical evidences are reviewed to critically evaluate the novel DLBCL management strategies. Expert commentary: New insights in DLBCL molecular characteristics should guide the therapeutic approach; the results of the current studies which are investigating safety and efficacy of novel 'X-RCHOP' will probably lead, in future, to a cell of origin (COO) based upfront therapy. Moreover, it is necessary to identify early patients with DLBCL who carried MYC, BCL2 and/or BCL6 rearrangements double hit lymphomas (DHL) because they should not receive standard R-CHOP but high intensity treatment as reported in many retrospective studies. New prospective trials are needed to investigate the more appropriate treatment of DHL.

What is the optimal initial management of the older MCL patient?

The current first line treatment of a patient with mantle cell lymphoma (MCL) is often considered as too toxic for elderly patients. The elderly, however, comprise the majority of the patients with MCL. The results of several recent studies have shown that the outcome of this patient group is not as dismal as in the past. Indeed, if patients are not considered frail, and can tolerate rituximab and moderate intensive chemotherapy such as R-CHOP followed by rituximab maintenance or R-bendamustine, a 4-year overall survival of >80% can be achieved. In this chapter the developments of the regimens, resulting in the standard treatment options for these patients, are discussed.

Rituximab-dose-dense chemotherapy with or without high-dose chemotherapy plus autologous stem-cell transplantation in high-risk diffuse large B-cell lymphoma (DLCL04): final results of a multicentre, open-label, randomised, controlled, phase 3 study

BACKGROUND

The prognosis of young patients with diffuse large B-cell lymphoma at high risk (age-adjusted International Prognostic Index [aa-IPI] score 2 or 3) treated with R-CHOP (rituximab, cyclophosphamide, vincristine, doxorubicin, and prednisone) is poor. The aim of this study was to investigate the possible benefit of intensification with high-dose chemotherapy and autologous stem-cell transplantation as part of first-line treatment in these patients.

METHODS

We did a multicentre, open-label, randomised, controlled, phase 3 trial with a 2 × 2 factorial design to compare, at two different R-CHOP dose levels, a full course of rituximab-dose-dense chemotherapy (no transplantation group) versus an abbreviated course of rituximab-dose-dense chemotherapy followed by consolidation with R-MAD (rituximab plus high-dose cytarabine plus mitoxantrone plus dexamethasone) and high-dose BEAM chemotherapy (carmustine, etoposide, cytarabine, and melphalan) plus autologous stem-cell transplantation (transplantation group) in young patients (18-65 years) with untreated high-risk diffuse large B-cell lymphoma (aa-IPI score 2-3). At enrolment, patients were stratified according to aa-IPI score and randomly assigned (1:1:1:1) to receive R-CHOP (intravenous rituximab 375 mg/m², cyclophosphamide 750 mg/m², doxorubicin 50 mg/m², and vincristine 1·4 mg/m² on day 1, plus oral prednisone 100 mg on days 1-5) delivered in a 14-day cycle (R-CHOP-14) for eight cycles; high-dose R-CHOP-14 (R-MegaCHOP-14; R-CHOP-14 except for cyclophosphamide 1200 mg/m² and doxorubicin 70 mg/m²) for six cycles; R-CHOP-14 for four cycles followed by R-MAD (intravenous rituximab 375 mg/m² on day 1 or 4 plus intravenous cytarabine 2000 mg/m² and dexamethasone 4 mg/m² every 12 h on days 1-3 plus intravenous mitoxantrone 8 mg/m² on days 1-3) plus BEAM (intravenous carmustine 300 mg/m² on day -7, intravenous cytarabine 200 mg/m² twice a day on days -6 to -3, intravenous etoposide 100 mg/m² twice a day on days -6 to -3, plus intravenous melphalan 140 mg/m² on day -2) and autologous stem-cell transplantation (day 0); or R-MegaCHOP-14 for four cycles followed by R-MAD plus BEAM and autologous stem-cell transplantation. The primary endpoint was failure-free survival at 2 years in the intention-to-treat population. This study is registered with EudraCT (2005-002181-14; 2007-000275-42) and with ClinicalTrials.gov, number NCT00499018.

FINDINGS

Between Jan 10, 2006, and Sept 8, 2010, 399 patients were randomly assigned to receive transplantation (n=199) or no transplantation (n=200); 203 patients were assigned to receive R-CHOP-14 and 196 were assigned to receive R-MegaCHOP-14. With a median follow-up of 72 months (IQR 57-88), 2-year failure-free survival was 71% (95% CI 64-77) in the transplantation group versus 62% (95% CI 55-68) in the no transplantation group (hazard ratio [HR] 0·65 [95% CI 0·47-0·91]; stratified log-rank test p=0·012). No difference in 5-year overall survival was observed between these groups (78% [95% CI 71-83] versus 77% [71-83]; HR 0·98 [0·65-1·48]; stratified log-rank test p=0·91). Grade 3 or worse haematological adverse events were reported in 183 (92%) of 199 patients in the transplantation group versus 135 (68%) of 200 patients in the no transplantation group. Grade 3 or worse non-haematological adverse events were reported in 90 (45%) versus 31 (16%); the most common grade 3 or worse non-haematological adverse event was gastrointestinal (49 [25%] vs 19 [10%]). Treatment-related deaths occurred in 13 (3%) patients; eight in the transplantation group and five in the no transplantation group.

INTERPRETATION

Abbreviated rituximab-dose-dense chemotherapy plus R-MAD plus BEAM and autologous stem-cell transplantation reduced the risk of treatment failure compared with full course rituximab-dose-dense chemotherapy in young patients with diffuse large B-cell lymphoma at high risk. However, these results might not be clinically meaningful, since this improvement did not reflect an improvement in overall survival. These results do not support further consideration of the use of intensification of R-CHOP as an upfront strategy in patients with diffuse large B-cell lymphoma with poor prognosis.

FUNDING

Fondazione Italiana Linfomi.

Synergistic interactions between PLK1 and HDAC inhibitors in non-Hodgkin's lymphoma cells occur in vitro and in vivo and proceed through multiple mechanisms

Interactions between the polo-like kinase 1 (PLK1) inhibitor volasertib and the histone deacetylase inhibitor (HDACI) belinostat were examined in diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL) cells in vitro and in vivo. Exposure of DLBCL cells to very low concentrations of volasertib in combination with belinostat synergistically increased cell death (apoptosis). Similar interactions occurred in GC-, ABC-, double-hit DLBCL cells, MCL cells, bortezomib-resistant cells and primary lymphoma cells. Co-exposure to volasertib/belinostat induced a marked increase in M-phase arrest, phospho-histone H3, mitotic errors, cell death in M-phase, and DNA damage. Belinostat diminished c-Myc mRNA and protein expression, an effect significantly enhanced by volasertib co-exposure. c-Myc knock-down increased DNA damage and cell death in response to volasertib, arguing that c-Myc down-regulation plays a functional role in the lethality of this regimen. Notably, PLK1 knock-down in DLBCL cells significantly increased belinostat-induced M-phase accumulation, phospho-histone H3, γH2AX, and cell death. Co-administration of volasertib and belinostat dramatically reduced tumor growth in an ABC-DLBCL flank model (U2932) and a systemic double-hit lymphoma model (OCI-Ly18), accompanied by a pronounced increase in survival without significant weight loss or other toxicities. Together, these findings indicate that PLK1/HDAC inhibition warrants attention as a therapeutic strategy in NHL.

Treatment of Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) comprises a heterogeneous group with pathophysiological, genetic and clinical features. Many patients can be cured with R-CHOP therapy, which is the current standard regimen. Despite recent progress in improving patient survival, the 40% survival of DLBCL patients remains poor. Therefore, the most important issue for patients with DLBCL remains the development of a new front-line therapy. Several studies have reported that intensified chemotherapy with dose-adjusted EPOCH-R or R-ACVBP was superior to R-CHOP. Gene expression profiling has identified two distinct forms of DLBCL: activated B cell-like (ABC) and germinal center B-cell-like (GCB) types. ABC DLBCL exhibits a worse prognosis than GCB DLBCL by molecular diagnosis after R-CHOP therapy. Next-generation sequencing has identified unique oncogenic mechanisms and genetic complexity, which has provided rational therapeutic targets. There are also a number of biomarkers, including CD5, and prognostic factors. Efforts to distinguish many biomarkers will be crucial for individualized treatment in the future.

Genetic and Epigenetic Modulation of CD20 Expression in B-Cell Malignancies: Molecular Mechanisms and Significance to Rituximab Resistance

CD20 is a differentiation related cell surface phosphoprotein that is expressed during early pre-B cell stages until plasma cell differentiation, and is a suitable molecular target for B-cell malignancies by monoclonal antibodies such as rituximab, ofatumumab, obinutuzumab and others. CD20 expression is confirmed in most B-cell malignancies; however, the protein expression level varies in each patient, even in de novo tumors, and down-modulation of CD20 expression after chemoimmunotherapy with rituximab, resulting in rituximab resistance, has been recognized in the clinical setting. Recent reports suggest that genetic and epigenetic mechanisms are correlated with aberrantly low CD20 expression in de novo tumors and relapsed/refractory disease after using rituximab. Furthermore, some targeting drugs, such as lenalidomide, bortezomib and ibrutinib, directly or indirectly affect CD20 protein expression. CD20-negative phenotypically-changed DLBCL after rituximab use tends to show an aggressive clinical course and poor outcome with resistance to not only rituximab, but also conventional salvage chemo-regimens. Understanding of the mechanisms of CD20-negative phenotype may contribute to establish strategies for overcoming chemo-refractory B-cell malignancies. In this manuscript, recent progress of research on molecular and clinical features of CD20 protein and CD20-negative B-cell malignancies was reviewed.

Mitotic catastrophe and cell cycle arrest are alternative cell death pathways executed by bortezomib in rituximab resistant B-cell lymphoma cells

The ubiqutin-proteasome system (UPS) plays a role in rituximab-chemotherapy resistance and bortezomib (BTZ) possesses caspase-dependent (i.e. Bak stabilization) and a less characterized caspase-independent mechanism-of-action(s). Here, we define BTZ-induced caspase-independent cell death pathways. A panel of rituximab-sensitive (RSCL), rituximab-resistant cell lines (RRCL) and primary tumor cells derived from lymphoma patients (N = 13) were exposed to BTZ. Changes in cell viability, cell-cycle, senescence, and mitotic index were quantified. In resting conditions, RRCL exhibits a low-proliferation rate, accumulation of cells in S-phase and senescence. Exposure of RRCL to BTZ reduces cell senescence, induced G2-M phase cell-cycle arrest, and is associated with mitotic catastrophe. BTZ stabilized p21, CDC2, and cyclin B in RRCL and in primary tumor cells. Transient p21 knockdown alleviates BTZ-induced senescence inhibition, G2-M cell cycle blockade, and mitotic catastrophe. Our data suggest that BTZ can induce apoptosis or mitotic catastrophe and that p21 has a pivotal role in BTZ activity against RRCL.

Oncogenic Signaling Pathways and Pathway-Based Therapeutic Biomarkers in Lymphoid Malignancies

Lymphoma is characterized by heterogeneous biology, pathologic features, and clinical outcome. This has been proven by accumulating pathologic and molecular evidence attributed to underlying aberrant alterations at genetic, epigenetic, transcriptional, protein, microenvironmental levels, and dysregulated oncogenic signaling pathways. In the era of precision medicine, targeting oncogenic pathways to design drugs and to optimize treatment regimens for the lymphoma patients is feasible and clinically significant. As such, further understanding of the biology and the mechanisms behind lymphoma development and identification of oncogenic pathway activation and pathway-based biomarkers to better design precise therapies are challenging but hopeful. Furthermore, pathway-based targeted therapies in combination with traditional chemotherapy, single specific targeted antibody therapy, and immunotherapy might raise the hope for the patients with lymphoma, especially for relapsed and refractory lymphoma patients.

The molecular pathogenesis of mantle cell lymphoma

Mantle cell lymphoma (MCL) is characterized by the translocation t(11;14) leading to constitutive cyclin D1 overexpression. However, overexpression of cyclin D1 alone is insufficient to cause malignant transformation. Secondary genetic alterations and deregulated signaling pathways involved in DNA damage response, cell proliferation, and apoptosis are indispensable for MCL lymphomagenesis. Recent studies investigating the biology of MCL have revealed crucial importance of B-cell receptor (BCR), nuclear factor-kappa B (NF-κB), phosphoinositide 3-kinase (PI3K), and BCL2 signaling for the molecular pathogenesis of MCL. In addition, activation of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3), NOTCH and WNT pathway can be observed in subsets of MCLs. These addictions can potentially be utilized therapeutically by implementing small molecule inhibitors into current treatment regimens.

Approach to the diagnosis and treatment of high-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements

High-grade B-cell lymphomas (HGBLs) with MYC and BCL2 and/or BCL6 rearrangements, so-called "double-hit" lymphomas (HGBL-DH), are aggressive lymphomas that form a separate provisional entity in the 2016 revised World Health Organization Classification of Lymphoid Tumors. Fluorescence in situ hybridization (FISH) will be required to identify HGBL-DH and will reclassify a subset of diffuse large B-cell lymphomas (DLBCLs) and HGBLs with features intermediate between DLBCL and Burkitt lymphoma into this new category. Identifying patients with HGBL-DH is important because it may change clinical management. This poses a challenge for centers that may not be ready to handle the additional workload and financial burden associated with the increase in requests for FISH testing. Herein, we review the mechanisms of deregulation of these oncogenes. We identify the factors associated with a poor prognosis and those that can guide diagnostic testing. Restricting FISH analysis to the 10% of DLBCL patients who have a germinal center B-cell phenotype and coexpress MYC and BCL2 proteins would be cost-effective and would identify the subset of patients who are at highest risk of experiencing a relapse following conventional therapy. These patients may benefit from intensified chemotherapy regimens or, ideally, should enroll in clinical trials investigating novel regimens.

Targeting mTOR for the treatment of B cell malignancies

Mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that functions as a key regulator of cell growth, division and survival. Many haematologic malignancies exhibit elevated or aberrant mTOR activation, supporting the launch of numerous clinical trials aimed at evaluating the potential of single agent mTOR-targeted therapies. While promising early clinical data using allosteric mTOR inhibitors (rapamycin and its derivatives, rapalogs) have suggested activity in a subset of haematologic malignancies, these agents have shown limited efficacy in most contexts. Whether the efficacy of these partial mTOR inhibitors might be enhanced by more complete target inhibition is being actively addressed with second generation ATP-competitive mTOR kinase inhibitors (TOR-KIs), which have only recently entered clinical trials. However, emerging preclinical data suggest that despite their biochemical advantage over rapalogs, TOR-KIs may retain a primarily cytostatic response. Rather, combinations of mTOR inhibition with other targeted therapies have demonstrated promising efficacy in several preclinical models. This review investigates the current status of rapalogs and TOR-KIs in B cell malignancies, with an emphasis on emerging preclinical evidence of synergistic combinations involving mTOR inhibition.

NF-κB signaling pathway and its potential as a target for therapy in lymphoid neoplasms

The NF-κB pathway, a critical regulator of apoptosis, plays a key role in many normal cellular functions. Genetic alterations and other mechanisms leading to constitutive activation of the NF-κB pathway contribute to cancer development, progression and therapy resistance by activation of downstream anti-apoptotic pathways, unfavorable microenvironment interactions, and gene dysregulation. Not surprisingly, given its importance to normal and cancer cell function, the NF-κB pathway has emerged as a target for therapy. In the review, we present the physiologic role of the NF-κB pathway and recent advances in better understanding of the pathologic roles of the NF-κB pathway in major types of lymphoid neoplasms. We also provide an update of clinical trials that use NF-κB pathway inhibitors. These trials are exploring the clinical efficiency of combining NF-κB pathway inhibitors with various agents that target diverse mechanisms of action with the goal being to optimize novel therapeutic opportunities for targeting oncogenic pathways to eradicate cancer cells.

Innovation in non-Hodgkin lymphoma drug discovery: what needs to be done?

INTRODUCTION

A new generation of anticancer agents called target drugs has been recently developed for the treatment of non-Hodgkin lymphomas. Current recovery rates in these diseases are up to 70% with immunotherapy based on the anti-CD20 monoclonal antibody combined with standard chemotherapeutics. However, there are still refractory or relapsed patients. Recently, several novel anti-lymphoma agents have been developed. Choosing the most effective personalized therapy still remains a crucial challenge in hematology. Areas covered: New drugs can specifically target malignant cells and inhibit cancer cell growth, proliferation and survival by specific interactions with one or more target proteins. Recent clinical studies have illustrated promising outcomes for novel drugs used as single agents and in combination with traditional therapeutics. In this article, the authors discuss novel targeted therapies with a promising outcome in NHL patients that are becoming integrated into treatment paradigms. Expert opinion: The development of new treatment options may help to avoid cytotoxic chemotherapy entirely in some clinical settings. Multicenter studies should be continued to investigate small agents and pathways inhibitors as this will enable us to enhance not only the duration of the treatment response but also the quality of the extended survival.

Clinical approach to diffuse large B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common subtype of lymphoma. We now recognize that DLBCL corresponds to a biologically heterogeneous family of diseases. Given the potential for cure for most DLBCL patients, appropriate diagnostic and staging evaluation and therapy are essential. Here we review areas of consensus as well as controversy in the evaluation, treatment and monitoring of patients with DLBCL and its related subtypes.

Everolimus combined with R-CHOP-21 for new, untreated, diffuse large B-cell lymphoma (NCCTG 1085 [Alliance]): safety and efficacy results of a phase 1 and feasibility trial

BACKGROUND

The PI3K-mTORC pathway is upregulated in diffuse large B-cell lymphoma (DLBCL) and can be targeted with the mTOR complex 1 (mTORC1) inhibitor everolimus. Everolimus has activity in relapsed DLBCL. These data provide the rationale to combine everolimus with standard treatment for DLBCL of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone delivered in a 21-day cycle (R-CHOP-21) for six cycles.

METHODS

We did a phase 1 and feasibility study (NCCTG 1085) of oral everolimus 10 mg/day plus R-CHOP-21 in patients aged at least 18 years with new, untreated, CD20-positive DLBCL (stages II-IV) in the NCCTG (Alliance) National Cancer Institute Cooperative Group (USA). Patients received standard R-CHOP-21 (intravenous rituximab 375 mg/m(2), intravenous cyclophosphamide 750 mg/m(2), intravenous doxorubicin 50 mg/m(2), and intravenous vincristine 1·4 mg/m(2) [maximum 2·0 mg] all on day 1 of the 21-day cycle; and oral prednisone 100 mg/m(2) each day on days 1-5 of the cycle) for six cycles with scheduled subcutaneous pegfilgrastim 6 mg on day 2 of each cycle. We tested two schedules: everolimus given in the fasting state either on days 1-10 or days 1-14 of the R-CHOP cycle. The primary endpoint of the phase 1 portion of this study was to establish the maximum tolerated dose of everolimus that could be combined with R-CHOP-21. The primary endpoint of the feasibility portion of the study was to determine the feasibility of the regimen, which was assessed by determining the rate of significant toxicity. Secondary endpoints were the proportion of patients who achieved an overall response, a complete response, event-free survival at 12 months and 24 months from enrolment, progression-free survival, and overall survival; relapse of DLBCL; and duration of response. We deemed patients as assessable for the primary endpoint in the phase 1 portion if they completed the first cycle as planned. In the feasibility portion, all patients who received at least one dose of everolimus were included. This trial is registered with ClinicalTrials.gov, number NCT01334502.

FINDINGS

Between March 21, 2012, and Sept 15, 2014, we enrolled 26 patients into the study. Two were ineligible, therefore results are presented for 24 eligible patients. Nine patients were enrolled into the phase 1 portion of the trial (three given everolimus on days 1-10, and six given everolimus on days 1-14) without any dose-limiting toxicities; therefore, everolimus 10 mg/day given on days 1-14 with R-CHOP-21 was tested in 15 additional patients for a total of 24. One (5%, 95% CI 0-24%) of 21 patients had a toxicity during the feasibility phase-a treatment delay of 12 days due to grade 3 hypokalaemia possibly related to everolimus. The median follow-up was 21·5 months (IQR 17-29). 23 (96%, 95% CI 79-100%) of 24 patients achieved an overall response, and all 23 (96%, 79-100%) also attained a complete metabolic response by PET. The remaining patient withdrew consent after in cycle 1 and attained a complete response with R-CHOP alone. All 24 (100%) patients met 12-month event-free survival, and nine had sufficient follow-up data to be event-free at 24 months. None of the 24 patients had died by the last follow-up (March 30, 2016), and none had had a relapse with DLBCL. Because no events occurred during the study or follow-up, we were unable to assess the duration of response or progression-free survival. The most common grade 3-4 adverse events were haematological; the most common of these was grade 4 neutropenia in 18 (75%) of 24 patients. Five (21%) of 24 had grade 3 febrile neutropenia.

INTERPRETATION

The mTORC1 inhibitor everolimus given for 14 days in combination with R-CHOP-21 for patients with DLBCL is safe. These findings suggest that drugs that target the PI3K-mTORC pathway add benefit when combined with standard R-CHOP. The everolimus with R-CHOP regimen should be tested against standard R-CHOP alone in a randomised trial, to support the benefits of this novel combination noted in this study.

FUNDING

National Cancer Institute of the US National Institutes of Health.

Bortezomib for the treatment of mantle cell lymphoma: an update

Bortezomib is a first in class proteasome inhibitor, initially approved by the US Food and Drug Administration for the treatment of plasma cell myeloma. Bortezomib has been approved for the treatment of relapsed and refractory mantle cell lymphoma (MCL) and, more recently, in the upfront setting as well. Treatment algorithms for MCL have rapidly evolved over the past two decades, and the optimal regimen remains to be defined. The choice of treatment regimen is based on disease risk stratification models, the expected toxicity of antineoplastic agents, the perceived patient ability to tolerate the planned treatments and the availability of novel agents. As new drugs with novel mechanisms of action and variable toxicity profiles come into use, treatment decisions for a given patient have become increasingly complex. This article provides an overview of the evolving use of bortezomib in the rapidly changing management landscape of MCL.

EBV-positive diffuse large B-cell lymphoma of the elderly: 2016 update on diagnosis, risk-stratification, and management

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) of the elderly is a provisional entity included in the 2008 WHO classification of lymphoid neoplasms. It is a disease typically seen in the elderly and thought to be associated with chronic EBV infection and severe immunosuppression with a component of immunosenescence. Recent research, however, has suggested that EBV-positive DLBCL can be seen in younger, immunocompetent patients. The diagnosis of EBV-positive DLBCL of the elderly is made through a careful pathological evaluation. The differential diagnosis includes infectious mononucleosis (specifically in younger patients), lymphomatoid granulomatosis, Hodgkin lymphoma, and gray zone lymphoma, among others. Detection of EBV-encoded RNA (EBER) is considered standard for diagnosis; however, a clear cutoff for positivity has not been defined. The International Prognostic Index (IPI), and the Oyama score can be used for risk-stratification. The Oyama score includes age >70 years and presence of B symptoms. The expression of CD30 is emerging as a potential adverse, and targetable, prognostic factor. Patients with EBV-positive DLBCL should be staged and managed following similar guidelines than patients with EBV-negative DLBCL. It has been suggested, however, that EBV-positive patients have a worse prognosis than EBV-negative counterparts in the era of chemoimmunotherapy. There is an opportunity to study and develop targeted therapy in the management of patients with EBV-positive DLBCL.

Programming the immune checkpoint to treat hematologic malignancies

INTRODUCTION

Hematologic malignancies manipulate the immune suppressive pathways involving CTLA-4, PD-1, and others to promote immune tolerance of cancer. New monoclonal antibodies targeting immune checkpoints are showing meaningful responses in the treatment of relapsed and refractory Hodgkin lymphoma, diffuse large B-cell lymphoma, follicular lymphoma, and chronic lymphocytic leukemia. The basis for success of anti-PD-1 therapy appears to be expression of PD-L1 on tumor cells and cells of the tumor microenvironment (TME). While adverse events associated with immune checkpoint inhibitors are capable of generating auto-immune phenomena, in general these therapies are well tolerated.

AREAS COVERED

In this review, the authors discuss the development of immune checkpoint inhibitors and activators which hold promise as useful therapies in malignancies of hematologic origin, since many exploit endogenous pathways to induce tolerance. By programming the immune response to attack hematologic malignancies, unique regimens can be developed to optimally treat patients with curative potential.

EXPERT OPINION

The utilization of immune checkpoint targeting agents to boost the innate and acquired immune systems to eradicate human malignancies represents a unique opportunity to develop novel therapies with increased clinical efficacy. Side effects of these therapies come with the price of auto-immune phenomena that require appropriate management.

Adolescent and young adult non-Hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) is a heterogeneous group of lymphoid malignancies accounting for a significant portion of cancers occurring in children, adolescents and young adults with an increasing incidence with age. The adolescent and young adult (AYA) population presents a specific set of characteristics and challenges. The most common diseases occurring in adolescents and young adults include Burkitt lymphoma, lymphoblastic lymphoma, diffuse large B-cell lymphoma, anaplastic large cell lymphoma and primary mediastinal B-cell lymphoma. There is also a higher incidence of primary central nervous system lymphoma in AYA patients. Cure rates largely depend on risk-stratification, and are generally superior to outcomes in comparison to older adult data but less than in younger children. Here, we review the unique clinical and biological characteristics of NHL occurring in the AYA population with a focus on how to achieve similar curative outcomes in AYA that have been established in younger cohorts.

Bortezomib: A Review in Mantle Cell Lymphoma in Previously Untreated Patients Unsuitable for Stem-Cell Transplantation

Bortezomib (Velcade(®)) is a proteasome inhibitor that is approved for the treatment of multiple myeloma and mantle cell lymphoma (MCL). This article reviews the efficacy and tolerability of bortezomib in combination with rituximab, cyclophosphamide, doxorubicin and prednisone (VR-CAP) in the treatment of previously untreated MCL unsuitable for stem-cell transplantation, and overviews the pharmacology of bortezomib. In the large, randomized, assessor-blinded, multinational LYM-3002 trial, induction therapy with VR-CAP improved progression-free survival significantly more than R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) after a median follow-up of 40 months in patients with newly diagnosed MCL ineligible or not considered for stem-cell transplantation. Complete response and certain other secondary endpoints were improved significantly more with VR-CAP than R-CHOP. Overall survival data were not mature at the time of assessment. The improved efficacy with VR-CAP was accompanied by an increased incidence of grade 3 or higher adverse events, particularly haematological adverse events.