Relapsed or Refractory Double-Expressor and Double-Hit Lymphomas Have Inferior Progression-Free Survival After Autologous Stem-Cell Transplantation

Treatment Outcomes with Standard of Care in Relapsed/Refractory Diffuse Large B-Cell Lymphoma: Real-World Data Analysis

INTRODUCTION

Despite new therapies for relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL), treatments with chemotherapy, single-agent rituximab/obinutuzumab, single-agent lenalidomide, or combinations of these agents continue to be commonly used.

METHODS

This retrospective study utilized longitudinal data from 4226 real-world electronic health records to characterize outcomes in patients with R/R DLBCL. Eligible patients were diagnosed with DLBCL between January 2010 and March 2022 and had R/R disease treated with ≥ 1 prior systemic line of therapy (LOT), including ≥ 1 anti-CD20-containing regimen.

RESULTS

A total of 573 patients treated with ≥ 1 prior LOT were included (31.2% and 13.4% with ≥ 2 and ≥ 3 prior LOTs, respectively). Median duration of follow-up was 7.7 months. Most patients (57.1%) were male; mean standard deviation (SD) age was 63 (14.7) years. Overall and complete response rates (95% confidence interval (CI) were 52% (48-56) and 23% (19-27). Median duration of response and duration of complete response were 3.5 and 18.4 months. Median progression-free and overall survival (95% CI) was 3.0 (2.8-3.3) and 12.9 (10.1-16.9) months, respectively. Patients with a higher number of prior LOTs, primary refractoriness, refractoriness to last LOT, refractoriness to last anti-CD20-containing regimen, and prior CAR T exposure had worse outcomes (i.e., challenging-to-treat R/R DLBCL) compared with those without these characteristics.

CONCLUSIONS

Outcomes in patients with R/R DLBCL treated with chemotherapy, single-agent rituximab/obinutuzumab, single-agent lenalidomide, or combinations of these agents remain poor, especially for those with challenging-to-treat R/R DLBCL. These findings underscore the unmet need for new, safe, and effective therapies, especially for challenging-to-treat R/R DLBCL populations.

Chidamide and orelabrutinib synergistically induce cell cycle arrest and apoptosis in diffuse large B-cell lymphoma by regulating the PI3K/AKT/mTOR pathway

OBJECTIVE

The initial therapeutic approach for diffuse large B-cell lymphoma (DLBCL) entails a rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) regimen. However, 40% of patients exhibit suboptimal responses, with some experiencing relapse and refractory conditions. This study aimed to explore novel therapeutic strategies and elucidate their underlying mechanisms in DLBCL.

METHODS

Bioinformatics techniques were employed to scrutinize correlations between the HDAC1, HDAC2, HDAC3, HDAC10, BTK, MYC, TP53, and BCL2 genes in DLBCL. In vitro experiments were conducted using DB and SU-DHL-4 cells treated with chidamide, orelabrutinib, and a combination of both. Cell viability was assessed by cell counting kit-8. Cell apoptosis and the cell cycle were determined using flow cytometry. Reactive oxygen species (ROS) production and mitochondrial function were assessed through ROS and JC-1 staining. RNA sequencing and western blot analyses were conducted to elucidate the molecular mechanisms underlying the combined action of chidamide and orelabrutinib in DLBCL cells.

RESULTS

This investigation revealed markedly enhanced antiproliferative effects when chidamide was combined with orelabrutinib. Compusyn software analysis indicated a synergistic effect of chidamide and orelabrutinib in inhibiting DLBCL cell proliferation, with a combination index (CI) < 1. This synergy further manifested as augmented cell cycle arrest, apoptosis induction, the downregulation of cell cycle-associated and antiapoptotic proteins, and the upregulation of proapoptotic proteins. Furthermore, the western blot and RNA-Seq findings suggested that combining chidamide and orelabrutinib modulated the PI3K/AKT/mTOR signaling pathway, thereby promoting DLBCL cell cycle arrest and apoptosis.

CONCLUSION

The findings of this study provide a compelling justification for the clinical utilization of chidamide and orelabrutinib to treat relapsed/refractory DLBCL.

Targeting HDACs for diffuse large B-cell lymphoma therapy

Histone deacetylases (HDACs) are involved in tumorigenesis and progression, however, their role in diffuse large B-cell lymphoma (DLBCL) is not well understood. In this study, we examined the expression levels, mutations, and clinical significance of HDACs in DLBCL. Additionally, we investigated the therapeutic potential of Chidamide, a novel HDAC inhibitor, to provide scientific evidence for targeting HDACs in DLBCL patients. We extracted transcriptome data of DLBCLs--including 47 lymph node samples and 337 whole-blood-cell controls--from The Cancer Genome Atlas. Bioinformatic analyses of HDAC expression, mutation, and correlation with the clinical significance of DLBCL patients were performed with the Gene Expression Profiling Interactive Analysis, GENEMANIA, and web-based software including cBioPortal and WebGestalt. To examine the therapeutic effect of Chidamide, DLBCL cell lines (WSU-DLCL-2 and DB cells) were employed. Cell proliferation and apoptosis were analyzed with Cell Counting Kit-8 and flow cytometry assays. The impact of Chidamide treatment was also analyzed by RNA sequencing of treated DB cells. Western blot was used to explore the molecular mechanism of the cytotoxicity of Chidamide on DLBCL cell lines. The expression of some HDACs (HDAC1, 2, 3, 4, 6, 7, 8, and 9) were significantly higher in the lymph node samples of DLBCL than that in whole-blood-cell controls. Moreover, we found that the mutation rate of HDACs was also higher in DLBCL tissues, although the overall survival of DLBCL patients was not associated with HDAC expression. Chidamide was found to have a cytotoxic effect on DLBCL cells in a dose-dependent manner, while transcriptome analysis and western blot revealed that using it for treatment impacted several biological processes, including PI3K/AKT signaling, mTOR signaling, the cell cycle, and apoptosis pathways. Alterations of HDAC genes, including enhanced expression and mutations, are positively related to DLBCL. Targeting HDACs with specific inhibitors such as Chidamide may represent a potential therapeutic approach for DLBCL patients.

A paradox of choice: Sequencing therapy in relapsed/refractory diffuse large B-cell lymphoma

The available treatments for relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) have experienced a dramatic change since 2017. Incremental advances in basic and translational science over several decades have led to innovations in immune-oncology. These innovations have culminated in eight separate approvals by the US Food and Drug Administration for the treatment of patients with R/R DLBCL over the last 10 years. High-dose therapy and autologous stem cell transplant (HDT-ASCT) remains the standard of care for transplant-eligible patients who relapse after an initial remission. For transplant-ineligible patients or for those who relapse following HDT-ASCT, multiple options exist. Monoclonal antibodies targeting CD19, antibody-drug conjugates, bispecific antibodies, immune effector cell products, and other agents with novel mechanisms of action are now available for patients with R/R DLBCL. There is increasing use of chimeric antigen receptor (CAR) T-cells as second-line therapy for patients with early relapse of DLBCL or those who are refractory to initial chemoimmunotherapy. The clinical benefits of these strategies vary and are influenced by patient and disease characteristics, as well as the type of prior therapy administered. Therefore, there are multiple clinical scenarios that clinicians might encounter when treating R/R DLBCL. An optimal sequence of drugs has not been established, and there is no evidence-based consensus on how to best order these agents. This abundance of choices introduces a paradox: proliferating treatment options are initially a boon to patients and providers, but as choices grow further they no longer liberate. Rather, more choices make the management of R/R DLBCL more challenging due to lack of direct comparisons among agents and a desire to maximize patient outcomes. Here, we provide a review of recently-approved second- and subsequent-line agents, summarize real-world data detailing the use of these medicines, and provide a framework for sequencing therapy in R/R DLBCL.

Prognostic significance of copy number gains of MYC detected by fluorescence in situ hybridization in large B-cell lymphoma

The MYC protooncogene plays a critical role in many cellular processes. MYC translocations are recurrent in large B-cell lymphomas (LBCLs) where they exhibit a negative effect on survival. Gain of MYC copies is also frequently identified; however, there is no consensus on the frequency and prognostic significance of MYC copy gains. We collected FISH data for MYC with reflex testing for BCL2 and BCL6 and IHC results at diagnosis for a cohort of 396 de novo and transformed LBCL cases and compared progression-free (PFS) and overall survival (OS) to determine the prognostic impact of extra MYC copies. The prevalence of cases with MYC copy number gain was 20.9%. PFS was shorter for patients with ≥5 MYC copies compared to controls (p = 0.0005, HR = 2.25). .MYC gain trended towards worse OS; patients with ≥7MYC copies had worse OS (p = 0.013), similar to patients with MYC translocations. We propose that MYC gain represents a dose-dependent prognostic factor for LBCLs.

Treatment of Relapsed or Refractory Diffuse Large B-Cell Lymphoma: New Approved Options

Overall, around 40% of patients with diffuse large B-cell lymphoma (DLBCL) have refractory disease or relapse after the first line of treatment. Until relatively recently, the prognosis of patients with relapsed or refractory DLBCL was very poor and treatment options were very limited. In recent years, several novel therapies have been approved that provide more effective options than conventional chemotherapy and that have manageable toxicity profiles. CAR-T cell therapy has become the new standard treatment for patients with refractory or early relapsed DLBCL, based on the positive results of the phase 3 ZUMA-7 and TRANSFORM clinical trials. This review addresses the role of CAR-T therapy and autologous stem cell transplantation in the treatment of these patients and other approved options for patients who are not candidates for transplant, such as the combinations of polatuzumab vedotin with bendamustine and rituximab, and tafasitamab with lenalidomide.

Characteristics and outcomes of children, adolescents and young adults with relapsed/refractory non-hodgkin lymphoma undergoing autologous stem cell transplant

BACKGROUND

There is paucity of data regarding outcomes of children, adolescents and young adults (CAYA) patients with non-Hodgkin lymphoma (NHL) undergoing autologous stem cell transplantation (ASCT).

METHODS

Patients aged 0-39 years undergoing first ASCT for NHL at MD Anderson Cancer Center between 2000 and 2020 were analyzed.

RESULTS

Two hundred twenty-one patients were included in the analysis, 129 (58%) were male and the median age was 32 (range 6-39) years. The most common histological subtypes were diffuse large B cell lymphoma (DLBCL) (44%), T-NHL (19%) and primary mediastinal B-Cell lymphoma (PMBCL) (19%). Younger patients (age ≤ 25) had lower incidence of DLBCL and higher incidence of PMBCL and T-NHL compared to older patients (age > 25) (P = 0.02). None of the younger patients had double hit (DH)/double expressor (DE) DLBCL, compared to 14 patients in the older age group (18%, P = 0.07). Considering the three main aggressive NHL subtypes (DLBCL, PMBCL and T-NHL), younger patients had numerically better 15-year post-transplant progression free survival (PFS) (67% vs. 54%) and overall survival (OS) (71% vs. 62%) compared to older patients, yet these differences did not reach statistical significance (P = 0.19 and P = 0.24, respectively). In multivariate analysis, not achieving a CR prior to ASCT was independently predictive of worse PFS [partial remission (PR) (HR, 3.9); stable disease (SD) (HR, 18.0), P = 0.03] and of worse OS [PR (HR, 4.2), SD (HR, 6.5) and progressive disease (HR, 4.7), P < 0.0001]. DH/DE status was an independent adverse predictor of PFS in multivariate analysis (HR 5.8, p = 0.03). Ten patients (4.5%) (all aged > 25 years) developed second primary malignancies (SPM), at a median of 34.4 (range, 1.0-196.6) months after ASCT, and SPM was the cause of death in five (50%) of them.

CONCLUSIONS

CAYA NHL patients aged ≤ 25 years who received ASCT presented a distinct NHL histology as compared to older CAYA patients, and none in this younger age group had DH/DE DLBCL. We observed a trend towards improved PFS and OS in younger patients. Disease status at ASCT was predictive of both PFS and OS. DH/DE status was an adverse predictor of PFS.

Second-line treatment of diffuse large B-cell lymphoma: Evolution of options

In the era of immunochemotherapy, approximately 60%-70% of diffuse large B-cell lymphoma (DLBCL) patients achieve remission with first-line rituximab-based chemoimmunotherapy. However, 30%-40% relapse after initial response to first-line therapy and, out of them, 20%-50% are refractory or experience early relapse. The second-line therapy algorithm for DLBCL has recently evolved, thanks to the recent approval of new therapeutic agents or their combinations. The new guidelines suggest a stratification of relapsed/refractory (R/R) DLBCL based on the time to relapse. For transplant-eligible patients, autologous stem cell transplant remains the preferred option when the patient relapses after 12 months from diagnosis, while anti-CD19 CART-cell therapy is the current preferred choice for high-risk DLBCL, defined as primary refractory or relapse ≤12 months. For transplant-ineligible or CAR T-cell therapy-ineligible patients, the therapeutic arsenal historically lacked effective options. However, new therapeutic options, including polatuzumab vedotin combined with bendamustine-rituximab and tafasitamab with lenalidomide, have been recently approved, and novel agents such as loncastuximab tesirine, selinexor, anti-CD19 CAR T-cell therapy, and bispecific antibodies have shown promising efficacy and manageable safety in this setting offering new hope to patients in this challenging scenario.

2024 Update: Advances in the risk stratification and management of large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with varying clinical outcomes. Our understanding of its molecular makeup continues to improve risk stratification, and artificial-intelligence and ctDNA-based analyses have the potential to enhance risk assessment and disease monitoring. R-CHOP and Pola-R-CHP are used in the frontline setting; chimeric antigen receptor therapy (CART) is now the new standard-of-care for most with primary refractory disease; both CART and autologous stem cell transplantation are utilized in the relapsed and refractory setting. In this review, we summarize the classification and management of DLBCL with an emphasis on recent advances in the field.

Minimal residual disease in patients with diffuse large B-cell lymphoma undergoing autologous stem cell transplantation

Improved biomarkers are required to guide the optimal use of autologous stem cell transplantation (ASCT) in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). We hypothesized that minimal residual disease (MRD) identified using immunoglobulin high-throughput sequencing in apheresis stem cell (ASC) samples, post-ASCT peripheral blood mononuclear cell (PBMC), and plasma samples could predict relapse. We studied 159 patients with R/R DLBCL who underwent ASCT, of whom 98 had an ASC sample and 60 had post-ASCT surveillance samples. After a median post-ASCT follow-up of 60 months, the 5-year progression-free survival (PFS) was 48%. MRD was detected in of 23/98 (23%) ASC samples and was associated with very poor PFS (5-year PFS 13% vs 53%, P < .001) and inferior overall survival (52% vs 68%, P = .05). The sensitivity and specificity of ASC MRD positivity for progression and death were 36% and 93%, respectively. Positive ASC MRD remained a significant predictor of PFS in multivariable analysis (hazard ratio [HR], 3.7; P < .001). Post-ASCT surveillance MRD testing of plasma, but not PBMC samples, reliably identified patients with an impending relapse. A positive plasma MRD result was associated with inferior PFS (HR, 3.0; P = .016) in a multivariable analysis. The median lead time from MRD detection to relapse was 62 days (range, 0-518 days). In conclusion, the detection of MRD in ASC samples is associated with a very high risk of relapse, justifying alternative treatment strategies or trials of novel consolidation options in these patients. Furthermore, post-ASCT MRD monitoring may facilitate the evaluation of the early initiation of treatment at molecular relapse. This trial has been registered at www.clinicaltrials.gov as #NCT02362997.

Clinical relevance of MYC/BCL2 expression and cell of origin in patients with diffuse large b-cell lymphoma treated with autologous transplant

Dual expression of MYC and BCL2 proteins (double-expressor lymphoma [DEL]) as well as cell of origin (COO) are important prognostic factors in patients with diffuse large B-cell lymphoma (DLBCL) after conventional chemotherapy. We studied the prognostic impact of DEL and COO in patients with relapsed DLBCL treated with autologous stem cell transplant (ASCT). Three-hundred and three patients with stored tissue samples were identified. Classification was successful in 267 patients: 161 (60%) were DEL/non-double hit (DHL), 98 (37%) were non-DEL/non-DHL, and 8 (3%) were DEL/DHL. Compared to non-DEL/non-DHL, DEL/DHL had worse overall survival while DEL/non-DHL did not significantly differ in overall survival. On multivariable analysis, DEL/DHL, age >60 years, and >2 prior therapies, but not COO, were important prognostic factors for overall survival. When we explored the interaction of COO and BCL2 expression, patients with germinal center B-cell (GCB)/BCL2 (+) had inferior progression-free survival (PFS) compared to GCB/BCL2 (-) patients (HR, 4.97; P = 0.027). We conclude that the DEL/non-DHL and non-DEL/non-DHL subtypes of DLBCL have similar survival after ASCT. The negative impact of GCB/BCL2 (+) on PFS warrants future trials targeting BCL2 after ASCT. The inferior outcomes in DEL/DHL need to be verified in a larger number of patients.

Evolving therapeutic landscape of diffuse large B-cell lymphoma: challenges and aspirations

Diffuse large B-cell lymphoma (DLBCL) represents the commonest subtype of non-Hodgkin lymphoma and encompasses a group of diverse disease entities, each harboring unique molecular and clinico-pathological features. The understanding of the molecular landscape of DLBCL has improved significantly over the past decade, highlighting unique genomic subtypes with implications on targeted therapy. At the same time, several new treatment modalities have been recently approved both in the frontline and relapsed settings, ending a dearth of negative clinical trials that plagued the past decade. Despite that, in the real-world setting, issues like drug accessibility, reimbursement policies, physician and patient preference, as well as questions regarding optimal sequencing of treatment options present difficulties and challenges in day-to-day oncology practice. Here, we review the recent advances in the therapeutic armamentarium of DLBCL and discuss implications on the practice landscape, with a particular emphasis on the context of the healthcare system in Singapore.

Patterns of Oncogene Coexpression at Single-Cell Resolution Influence Survival in Lymphoma

Cancers often overexpress multiple clinically relevant oncogenes, but it is not known if combinations of oncogenes in cellular subpopulations within a cancer influence clinical outcomes. Using quantitative multispectral imaging of the prognostically relevant oncogenes MYC, BCL2, and BCL6 in diffuse large B-cell lymphoma (DLBCL), we show that the percentage of cells with a unique combination MYC+BCL2+BCL6- (M+2+6-) consistently predicts survival across four independent cohorts (n = 449), an effect not observed with other combinations including M+2+6+. We show that the M+2+6- percentage can be mathematically derived from quantitative measurements of the individual oncogenes and correlates with survival in IHC (n = 316) and gene expression (n = 2,521) datasets. Comparative bulk/single-cell transcriptomic analyses of DLBCL samples and MYC/BCL2/BCL6-transformed primary B cells identify molecular features, including cyclin D2 and PI3K/AKT as candidate regulators of M+2+6- unfavorable biology. Similar analyses evaluating oncogenic combinations at single-cell resolution in other cancers may facilitate an understanding of cancer evolution and therapy resistance.

SIGNIFICANCE

Using single-cell-resolved multiplexed imaging, we show that selected subpopulations of cells expressing specific combinations of oncogenes influence clinical outcomes in lymphoma. We describe a probabilistic metric for the estimation of cellular oncogenic coexpression from IHC or bulk transcriptomes, with possible implications for prognostication and therapeutic target discovery in cancer. This article is highlighted in the In This Issue feature, p. 1027.

Characteristics and Outcomes of Children, Adolescents and Young Adults with Relapsed/Refractory Non-Hodgkin Lymphoma Undergoing Autologous Stem Cell Transplant

There is paucity of data regarding outcomes of children, adolescents and young adults (CAYA) patients with non-Hodgkin lymphoma (NHL) undergoing autologous hematopoietic stem cell transplantation (ASCT). We analyzed 222 patients aged 0-39 years undergoing first ASCT for NHL between 2000 and 2020. The most common histological subtypes were DLBCL (44%), T-NHL (19%) and PMBCL (19%). Younger patients (age ≤ 25) had lower incidence of DLBCL and higher incidence of PMBCL and T-NHL compared to older patients (> 25 years) (P = 0.02). None of the younger patients had DH)/DE DLBCL, as compared to 14 patients in the older group (18%, P = 0.07). Younger patients had numerically better 15-year post-transplant PFS (67% vs. 54%) and OS (71% vs. 62%) compared to older patients, without statistically significant differences (P = 0.19 and P = 0.24, respectively). In MVA, not achieving a CR prior to ASCT was independently predictive of worse PFS (P < 0.0001). DH/DE status was an independent adverse predictor of PFS in MVA (HR 5.8, p = 0.03). 10 patients(4.5%) (all aged > 25 years) developed SPM Patients aged ≤ 25 years presented a distinct NHL histology as compared to older CAYA patients. Disease status at ASCT was predictive of both PFS and OS. DH/DE status was an adverse predictor of PFS.

Cell of origin is not associated with outcomes of relapsed or refractory diffuse large B cell lymphoma

Activated B cell (ABC) type diffuse large B cell lymphoma (DLBCL), double hit lymphoma (DHL) and double expressor lymphoma (DEL) have poor outcomes to frontline R-CHOP but impact of these molecular features on outcomes of relapsed/refractory (R/R) disease is not well-characterized. We evaluated the association of diagnostic cell of origin (COO), double hit and double expressor status with overall survival after first relapse in DLBCL patients who were enrolled into the Molecular Epidemiology Resource (MER) cohort. COO was available from immunohistochemistry (IHC) using Hans criteria or gene expression profiling (GEP) (Nanostring) on the diagnostic FFPE biopsy. Of 373 pts with R/R DLBCL, 278 had COO by IHC: 152 were GCB, 107 were non-GCB. One hundred and fourty had COO by GEP: 44 were ABC, 65 were GCB and 13 were unclassifiable. Nineteen out of 163 (12%) were DHL; 30 out of 135 (22%) had DEL. COO, either by IHC (2 years OS GCB: 45% [CI95 : 38-54] vs. non-GCB: 44% [CI95 :36-55], p > 0.05) or GEP (2 years OS ABC: 42% [CI95 : 29-59] vs. GCB: 40% [CI95 : 30-54], p > 0.05), was not associated with difference in OS. DHL (2 years OS 16 [CI95 :6-45] vs. 45% [CI95 : 34-59], p < 0.01) and DEL (2 years OS 33% [CI95 : 20-56], vs. 50% [CI95 : 41-60], p < 0.05) had lower OS than non-DHL and non-DEL/non-DHL counterparts, respectively. COO by IHC or GEP was not associated with OS in R/R DLBCL while DHL and DEL were adverse prognostic markers in DLBCL at first relapse.

Genetic Profiling of Diffuse Large B-Cell Lymphoma: A Comparison Between Double-Expressor Lymphoma and Non-Double-Expressor Lymphoma

INTRODUCTION

Data are limited regarding the genetic profiling of diffuse large B-cell lymphoma (DLBCL) with double expression of MYC and BCL2 proteins without underlying rearrangements (double-expressor lymphoma [DEL]). This study aimed to describe the genetic profiling and determine the prognostic significance in patients with DEL and in those with non-DEL.

METHODS

Capture-based targeted sequencing was performed on 244 patients with de novo DLBCL, not otherwise specified. Immunohistochemistry staining was performed for evaluating the MYC and BCL2 expression.

RESULTS

Among 244 patients, 46 patients had DEL, and 198 had non-DEL. KMT2D, CD58, EP300, PRDM1, TNFAIP3 and BCL2 gain or amplification (BCL2^GA/AMP) were significantly more frequently altered in the DEL group. Alterations in the BCR/TLR (p = 0.021), B-cell development and differentiation (p = 0.004), and NF-κB (p = 0.034) pathways occurred more frequently in patients with DEL. Thirty-seven DEL patients and 132 non-DEL patients were included for survival analyses. DEL was not significantly associated with progression-free survival (PFS) (p = 0.60) and overall survival (OS) (p = 0.49). In DEL patients, after adjusting for the International Prognostic Index, BCL2 alteration (HR 2.516, 95% CI 1.027-6.161; p = 0.044) remained an independent predictor of inferior PFS. BCL2^GA/AMP also predicted poor PFS, but with marginal statistical significance (HR 2.489, 95% CI 0.995-6.224; p = 0.051).

CONCLUSION

There was difference in profiling of altered genes and signaling pathways between the DEL group and the non-DEL group. The presence of DEL alone should not be considered as an adverse prognostic indicator, and BCL2 alteration could define a subset of patients with poor prognosis within DEL.

A combination of BR101801 and venetoclax enhances antitumor effect in DLBCL cells via c-Myc/Bcl-2/Mcl-1 triple targeting

Double hit diffuse large B-cell lymphoma (DLBCL) with rearrangement and overexpression of both c-Myc and Bcl-2 responds poorly to standard R-CHOP therapy. In a recent phase I study, Venetoclax (ABT-199) targeting Bcl-2 also exhibited disappointing response rates in patients with relapsed/refractory DLBCL, suggesting that targeting only Bcl-2 is not sufficient for achieving successful efficacy due to the concurrent oncogenic function of c-Myc expression and drug resistance following an increase in Mcl-1. Therefore, co-targeting c-Myc and Mcl-1 could be a key combinatorial strategy to enhance the efficacy of Venetoclax. In this study, BR101801 a novel drug for DLBCL, effectively inhibited DLBCL cell growth/proliferation, induced cell cycle arrest, and markedly inhibited G0/G1 arrest. The apoptotic effect of BR101801 was also observed by increased Cytochrome C, cleaved PARP, and Annexin V-positive cell populations. This anti-cancer effect of BR101801 was confirmed in animal models, where it effectively inhibited tumor growth by reducing the expression of both c-Myc and Mcl-1. Furthermore, BR101801 exhibited a significant synergistic antitumor effect even in late xenograft models when combined with Venetoclax. Our data strongly suggest that c-Myc/Bcl-2/Mcl-1 triple targeting through a combination of BR101801 and Venetoclax could be a potential clinical option for double-hit DLBCL.

Management Considerations for Patients With Primary Refractory and Early Relapsed Diffuse Large B-Cell Lymphoma

Most patients with diffuse large B-cell lymphoma (DLBCL) will be cured with up-front chemoimmunotherapy, but 30%-40% of patients will experience relapsed disease. Historically, salvage chemotherapy followed by autologous stem-cell transplant (ASCT) was the mainstay of treatment for these patients. However, research has demonstrated that patients with primary refractory or early relapsed (R/R; high-risk) DLBCL do not benefit from ASCT, prompting investigation into other options. With the advent of chimeric antigen receptor (CAR) T-cell therapy, treatment of R/R DLBCL has changed dramatically. With positive outcomes in the TRANSFORM and ZUMA-7 trials with manageable toxicity profiles, approval was obtained for lisocabtagene maraleucel (liso-cel) and axicabtagene ciloleucel (axi-cel) as second-line therapies for high-risk R/R DLBCL. However, these trials required patients to be medically fit for ASCT. In PILOT, liso-cel was deemed a reasonable treatment option for R/R transplant-ineligible patients. We recommend either axi-cel or liso-cel for fit patients with high-risk R/R DLBCL or liso-cel for unfit R/R patients as a second-line therapy. If CAR T-cell therapy is not an option, we recommend consideration of either ASCT if the patient has chemosensitive disease and is fit or clinical trial if the patient is unfit or has chemoresistant disease. If trials are not an option, alternative treatments are available. With the advent of additional therapies such as bispecific T-cell-engaging antibodies, the treatment landscape of R/R DLBCL may be upended. There continue to be many unanswered questions in the management of patients with R/R DLBCL, but given the promise of cellular therapies, outcomes are more optimistic in this group with historically dismal survival.

No difference in treatment outcome between patients with nodal versus extranodal diffuse large B-cell lymphoma

Background and Aim

Diffuse large B-cell lymphoma (DLBCL) has been classified using various parameters, including the site of origin. Studies have reported conflicting outcomes when DLBLC patients were stratified according to the site of origin. This study aimed to investigate the response rate and survival outcomes in nodal versus extranodal DLBCL and compare the results to a region-matched study covering the 1988 - 2005 period.

Methods

A single-center retrospective cohort study was conducted on all patients diagnosed with DLBCL and treated in a tertiary care hospital in Pakistan during 2014 - 2019. We calculated the mean and median for continuous variables and frequency and percentages for all categorical variables. Progression-free survival (PFS) and overall survival (OS) were calculated using Kaplan-Meier survival curves. A Cox proportional hazards model was used to determine the hazard ratio (HR) for OS.

Results

Of the 118 patients, 49 patients (41.5%) had nodal disease and 69 patients (58.5%) were diagnosed with extranodal DLBCL. The majority of patients in the nodal and extranodal cohorts presented with Stages III and IV disease (73.4% and 62.3%, respectively). A complete response to (immuno) chemotherapy was achieved in 71.4% of nodal DLBCL patients and 65.2% of extranodal DLBCL patients. The 5-year PFS and median PFS in the entire cohort were 0.8% and 17 m, respectively. The PFS and median PFS in the nodal and extranodal DLBCL cohort were 0% and 1.4%, respectively, and 15 m and 19 m, respectively. The 5-year OS and median OS in the entire cohort were 16.1% and 19 m, respectively. The OS and median OS in the nodal and extranodal DLBCL cohort were 8.2% and 21.7%, respectively, and 19 m and 21 m, respectively. Multivariable linear regression revealed that the ABC phenotype (nodal, HR = 1.37, 95% CI = 1.37 - 3.20; extranodal, HR = 1.65, 95% CI = 1.46 - 3.17; GBC as reference) and double and triple hit DLBCL (nodal, HR = 1.29, 95% CI = 1.19 - 2.81; extranodal, HR = 1.87, 95% CI = 1.28 - 2.43; and non-expressors as reference) are independent negative predictors of OS.

Conclusions

DLBCL incidence in the Karachi region has remained comparable but patient composition in the extranodal DLBCL cohort has shifted to predominantly advanced stage. Nodal and extranodal DLBCL were associated with similar PFS and OS profiles and first- and second-line treatment responses. Cell of origin and antigen expression status was independent negative predictors of OS, disfavoring the ABC phenotype and lesions with c-MYC and BCL2 and/or BCL6 overexpression.

Relevance for Patients

DLBCL is an aggressive type of non-Hodgkin's lymphoma, however; patients respond well to standard systemic chemotherapy. Extranodal type of DLBCL patients tend to have more residual disease after first-line systemic chemotherapy, but physicians should keep in mind that the subsequent line treatment mitigates its negative impact on survival.

The role of CAR-T cell therapy as second line in diffuse large B-cell lymphoma

For approximately three decades, autologous hematopoietic cell transplantation (auto-HCT) has been the standard of care for patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) after frontline therapy. This approach is limited due to the intensity of chemotherapy and the proportion of patients who relapse after auto-HCT. Since the approval of anti-CD19 chimeric antigen receptor T-cell (CAR-T) therapy and novel agents, the treatment paradigm for DLBCL has changed remarkably. Anti-CD19 CAR-T therapy was first approved for relapsed DLBCL after two or more previous lines of therapy with long-lasting responses, with over 50% of patients still alive at 5-year follow-up. Here, we discuss recent randomized phase 3 clinical trials using axicabtagene ciloleucel, tisagenlecleucel, and lisocabtagene maraleucel in the second-line therapy setting compared with the standard of care in transplant-eligible patients who have DLBCL R/R within 12 months of completing chemo-immunotherapy, potentially changing the treatment algorithm for DLBCL.

Patterns of Utilization and Outcomes of Autologous Stem Cell Transplantation and Chimeric Antigen Receptor T-Cell Therapy in Relapsed or Refractory Diffuse Large B-cell Lymphomas with MYC and BCL2 and/or BCL6 Rearrangements

BACKGROUND

Patients with Diffuse Large Bcell Lymphoma (DLBCL) with MYC and BCL2 and/or BCL6 gene rearrangements [double-hit lymphoma/triple-hit lymphoma (DHL/THL)] have poor prognosis in the relapsed/refractory setting.

METHODS

We utilized a real-world deidentified database of DLBCL patients and report patterns of therapy utilization in relapsed/refractory DLBCL. We used log-rank test to compare real-world overall survival (rwOS) among DHL and non-DHL subgroups for CAR Tcell therapy or ASCT respectively, stratified for prior lines of therapy.

RESULTS

Of all 7,877 patients with DLBCL, 367 patients had DHL while 6113 had non-DHL. Second line chemotherapy was administered to 147 DHL patients and 1517 non-DHL. 1393 were excluded, including 934 with unknown DHL/THL status. Approximately 47% received salvage intent chemotherapy in the DHL subgroup, of which 19% patients eventually received ASCT, while 34% received salvage intent chemotherapy in the non-DHL/THL group with 32% receiving ASCT. DHL/THL status negatively influenced median rwOS for patients who underwent ASCT in the second-line while it was associated with numerically inferior but without statistically significant rwOS among patients that underwent CAR Tcell therapy on multivariable analysis.

CONCLUSION

rwOS of relapsed DHL/THL is inferior to non-DHL/THL. Fewer patients with DHL/THL were able to proceed with ASCT after salvage chemotherapy compared to non-DHL/THL. ASCT as second-line therapy for relapsed DHL/THL had worse rwOS than for non-DHL/THL, consistent with the natural history of DHL/THL. This difference was not seen for CAR Tcell therapy, which combined with promising results from clinical trials, suggests a greater role for CAR T-cell therapy in relapsed/refractory DHL.

Enhanced lipid metabolism confers the immunosuppressive tumor microenvironment in CD5-positive non-MYC/BCL2 double expressor lymphoma

Lymphoma cells expressing CD5 (CD5+) confer inferior outcome of diffuse large B-cell lymphoma (DLBCL), especially in non–MYC/BCL2 double expressor (non-DE) patients. In tumor microenvironment, CD5+ non-DE tumor revealed increased proportion of immunosuppressive M2 macrophages and enhanced pathways related to macrophage activation and migration. In accordance to M2 activation, lipid metabolism was upregulated, including fatty acid uptake and fatty acid oxidation, which supplied energy for M2 macrophage polarization and activation. Meanwhile, CD36 expression was upregulated and strongly correlated to the proportion of M2 macrophages in CD5+ non-DE DLBCL. In vitro, a DLBCL cell line (LY10) overexpressing CD5 significantly increased M2 proportion in comparison with control when cocultured with peripheral blood mononuclear cells (PBMCs). The addition of metformin significantly decreased the M2 proportion and the CD36 expression level in the coculture systems, indicating that metformin could target altered lipid metabolism and decrease M2 macrophages in DLBCL, especially in CD5+ non-DE lymphoma. In conclusion, enhanced lipid metabolism and M2 macrophage activation contributed to the immunosuppressive tumor microenvironment and could be potential therapeutic targets in CD5+ non-DE DLBCL.

R-CHOP Vs DA-EPOCH-R for Double-Expressor Lymphoma: A University of California Hematologic Malignancies Consortium Retrospective Analysis

BACKGROUND

Managing double-expressor lymphomas (DEL) is controversial given the dearth of data and lack of standardized guidelines on this high-risk subset of lymphomas. No prospective and few retrospective studies limited by either their sample size or short follow-up address the question of initial treatment of choice for DEL. We performed the largest analysis to date exploring R-CHOP vs DA-EPOCH-R in DEL.

METHODS

Adults with DEL diagnosed from 6/2012-2/2021 at 4 unique sites were retrospectively analyzed. Progression-free survival (PFS) was the primary endpoint. Key secondary endpoints include overall survival (OS), overall and complete response rates (ORR and CRR), cumulative incidence of relapse, and autologous hematopoietic cell transplantation (autoHCT) utilization.

RESULTS

155 patients were included, 61 treated with R-CHOP and 94 with DA-EPOCH-R. 3-year PFS and OS were similar between R-CHOP and DA-EPOCH-R, 33.2% vs 57.2%,(P = .063), and 72.2% vs 71.6% (P = .43) after median follow-up times of 2.43 and 2.89 years, respectively. Patients <65 had improved PFS with DA-EPOCH-R, hazard ratio 0.41 (P = .01). CRR and ORR rates were also similar. Relapse rates were not statistically different, 51.9% vs 28.6% (P = .069). AutoHCT utilization was higher with R-CHOP vs DA-EPOCH-R, 23.0% vs 8.5% (P = .017).

CONCLUSIONS

Our findings do not support the use of DA-EPOCH-R over R-CHOP for DEL. Patients <65 years may experience longer PFS with DA-EPOCH-R, but limitations to the analysis make this interpretation difficult.

Role of CD19 Chimeric Antigen Receptor T Cells in Second-Line Large B Cell Lymphoma: Lessons from Phase 3 Trials. An Expert Panel Opinion from the American Society for Transplantation and Cellular Therapy

Since 2017, 3 CD19-directed chimeric antigen receptor (CAR) T cell therapies-axicabtagene ciloleucel, tisagenlecleucel, and lisocabtagene maraleucel-have been approved for relapsed/refractory aggressive diffuse large B cell lymphoma after 2 lines of therapy. Recently, 3 prospective phase 3 randomized clinical trials were conducted to define the optimal second-line treatment by comparing each of the CAR T cell products to the current standard of care: ZUMA-7 for axicabtagene ciloleucel, BELINDA for tisagenlecleucel, and TRANSFORM for lisocabtagene maraleucel. These 3 studies, although largely addressing the same question, had different outcomes, with ZUMA-7 and TRANSFORM demonstrating significant improvement with CD19 CAR T cells in second-line therapy compared with standard of care but BELINDA not showing any benefit. The US Food and Drug Administration has now approved axicabtagene ciloleucel and lisocabtagene maraleucel for LBCL that is refractory to first-line chemoimmunotherapy or relapse occurring within 12 months of first-line chemoimmunotherapy. Following the reporting of these practice changing studies, here a group of experts convened by the American Society for Transplantation and Cellular Therapy provides a comprehensive review of the 3 studies, emphasizing potential differences, and shares perspectives on what these results mean to clinical practice in this new era of treatment of B cell lymphomas.

Novel Immune-Based treatments for Diffuse Large B-Cell Lymphoma: The Post-CAR T Cell Era

Prognosis for patients with refractory/relapsed (R/R) diffuse large B-cell lymphoma (DLBCL) is poor. Immune-based therapeutic treatments such as CD19 Chimeric Antigen Receptor (CAR) T cell therapies have dramatically changed the treatment landscape for R/R DLBCL leading to durable remissions in ~ 50% of patients. However, there remains an unmet need for developing novel therapies to improve clinical outcomes of patients not responding or relapsing after CAR T cell therapies. Lack of suitable immunotherapeutic targets and disease heterogeneity represent the foremost challenges in this emerging field. In this review, we discuss the recently approved and emerging novel immunotherapies for patients with R/R DLBCL in the post-CAR T era and the cell surface targets currently used.

A multicenter retrospective study of polatuzumab vedotin in patients with large B-cell lymphoma after CAR T-cell therapy

Polatuzumab vedotin (PV) is an antibody-drug conjugate targeting CD79b that is approved for patients with relapsed/refractory large B-cell lymphoma (LBCL). Patients who relapse after chimeric antigen receptor (CAR) T-cell therapy were not included in the registration study, and reports of PV use after CAR T cells are limited. This multicenter retrospective analysis included patients with LBCL who relapsed or progressed after CAR T-cell therapy and subsequently received PV with or without rituximab and bendamustine between July 2019 and May 2021. Response to treatment and progression were assessed based on the 2014 Lugano criteria. Fifty-seven patients were included in the study: 18 (32%) patients were primary refractory to CAR T-cell therapy, and 34 (60%) patients received PV-based therapy immediately after CAR T-cell therapy. PV was combined with rituximab in 54 (95%) patients and administered with bendamustine in 35 (61%) patients. A response was achieved in 25 (44%) patients, including complete remission in 8 (14%). No significant association between baseline characteristics and response was observed. After a median follow-up of 47 weeks (95% confidence interval [CI], 40-54), 46 (81%) patients had disease progression or died, and the median progression-free survival was 10 weeks (95% CI, 5-15). On a multivariate analysis, bone marrow involvement (hazard ratio, 5.2; 95% CI, 1.8-15; P = .003) and elevated lactate dehydrogenase levels (hazard ratio, 5.0; 95% CI, 1.4-16; P = .01) were associated with shorter progression-free survival. Studies aimed at better characterizing the intrinsic mechanism of resistance and identifying optimal consolidation strategies for these patients are warranted.

Fitting double-hit lymphoma into the aggressive lymphoma spectrum: a square peg in a round hole?

High-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements or both, commonly called double-hit lymphoma (DHL), is an aggressive B-cell lymphoma that is molecularly distinct from diffuse large B-cell lymphoma (DLBCL) and is associated with poor outcomes. Recent advances in the molecular classification of DLBCL have identified distinct subsets, including genetic signatures which correlate with DHL and survival. DHL with concomitant TP53 mutation appears to be associated with a very poor prognosis. Standard chemo-immunotherapy is not an effective treatment for these patients and personalized, innovative strategies are needed. In this review, we summarize recent advances in the subclassification of DLBCL, with a focus on DHL. We also incorporate early, promising clinical trial data using CAR T and targeted therapies. Rationally designed clinical trials for DLBCL are needed to advance the care of patients with DHL and other adverse risk DLBCL subgroups.

BCL2 super-expressor diffuse large B-cell lymphoma: a distinct subgroup associated with poor prognosis

Overexpression of the BCL2 protein has been reported as a poor prognostic factor for diffuse large B-cell lymphoma (DLBCL). However, there are currently no standardized criteria for evaluating BCL2 protein expression. We aimed to evaluate the prognostic value of BCL2 expression determined by immunohistochemistry (IHC), incorporating both the staining intensity and proportion, in patients with de novo DLBCL who received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) as first-line treatment. We defined tumors with BCL2 expression in nearly all tumor cells with a uniformly strong intensity by IHC as BCL2 super-expressor. The BCL2 super-expressors (n = 35) showed significantly worse event-free survival (EFS; HR, 1.903; 95% CI, 1.159-3.126, P = 0.011) and overall survival (OS; HR, 2.467; 95% CI, 1.474-4.127, P = 0.001) compared with the non-BCL2 super-expressors (n = 234) independent of the international prognostic index (IPI), cell of origin (COO), and double expressor status in the training set (n = 269). The adverse prognostic impact of BCL2 super-expression was confirmed in the validation set (n = 195). When the survival outcomes were evaluated in the entire cohort (n = 464), BCL2 super-expressor group was significantly associated with inferior EFS and OS regardless of IPI, COO, MYC expression, and stages. BCL2 super-expressors had genetic aberrations enriched in the NOTCH and TP53 signaling pathways. This study suggests that the BCL2 super-expressor characterizes a distinct subset of DLBCL with a poor prognosis and warrants further investigation as a target population for BCL-2 inhibitors.

Altered pathways and targeted therapy in double hit lymphoma

High-grade B-cell lymphoma with translocations involving MYC and BCL2 or BCL6, usually referred to as double hit lymphoma (DHL), is an aggressive hematological malignance with distinct genetic features and poor clinical prognosis. Current standard chemoimmunotherapy fails to confer satisfying outcomes and few targeted therapeutics are available for the treatment against DHL. Recently, the delineating of the genetic landscape in tumors has provided insight into both biology and targeted therapies. Therefore, it is essential to understand the altered signaling pathways of DHL to develop treatment strategies with better clinical benefits. Herein, we summarized the genetic alterations in the two DHL subtypes (DHL-BCL2 and DHL-BCL6). We further elucidate their implications on cellular processes, including anti-apoptosis, epigenetic regulations, B-cell receptor signaling, and immune escape. Ongoing and potential therapeutic strategies and targeted drugs steered by these alterations were reviewed accordingly. Based on these findings, we also discuss the therapeutic vulnerabilities that coincide with these genetic changes. We believe that the understanding of the DHL studies will provide insight into this disease and capacitate the finding of more effective treatment strategies.

Molecular Pathology of Lung Cancer

This overview of the molecular pathology of lung cancer includes a review of the most salient molecular alterations of the genome, transcriptome, and the epigenome. The insights provided by the growing use of next-generation sequencing (NGS) in lung cancer will be discussed, and interrelated concepts such as intertumor heterogeneity, intratumor heterogeneity, tumor mutational burden, and the advent of liquid biopsy will be explored. Moreover, this work describes how the evolving field of molecular pathology refines the understanding of different histologic phenotypes of non-small-cell lung cancer (NSCLC) and the underlying biology of small-cell lung cancer. This review will provide an appreciation for how ongoing scientific findings and technologic advances in molecular pathology are crucial for development of biomarkers, therapeutic agents, clinical trials, and ultimately improved patient care.

High grade B-cell lymphoma with MYC, BCL2 and/or BCL6 rearrangements: unraveling the genetic landscape of a rare aggressive subtype of non-Hodgkin lymphoma

High-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (DH/TH-HGBL) still miss an in-depth genomic characterization. To identify accompanying genetic events, we performed a pilot study on 7 cases by applying DNA microarray and targeted NGS sequencing. Interestingly, the genetic background of DH/TH-HGBL is largely overlapping with that of other high-grade/poor prognosis lymphomas. Namely, copy number abnormalities were trisomy of chromosome 7 and chromosome 8q gain, encompassing MYC. Among gene variants, those affecting transcription factors (MYC, FOXO1), epigenetic modulators (KMT2D, EZH2 and CREEBP), and anti-apoptotic gene (BCL2), were recurrent. MYC and BCL2 were mutated in 3 and 5 cases, respectively. In addition, mutations of FOXO1, previously reported in Diffuse Large B-Cell Lymphomas, were also detected. Clarifying the genomic background of this subset of high-risk lymphomas will pave the way for the clinical use of new biomarkers to: (1) monitor treatment response and; (2) consider alternative targeted therapies.

Double-hit lymphoma: optimizing therapy

Aggressive B-cell lymphoma is a heterogeneous entity with disparate outcomes based on clinical and pathological characteristics. While most tumors in this category are diffuse large B-cell lymphoma (DLBCL), the recognition that some cases have high-grade morphology and frequently harbor MYC and BCL2 and/or BCL6 translocations has led to their separate categorization. These cases are now considered distinct from DLBCL and are named "high-grade B-cell lymphoma" (HGBL). Most are characterized by distinct rearrangements, but others have high-grade morphological features without these and are called HGBL-not otherwise specified. Studies have demonstrated that this group of diseases leads to poor outcomes following standard rituximab, cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone therapy; retrospective and recent single-arm, multicenter studies suggest they should be approached with dose-intense treatment platforms. As yet, this has not been validated in randomized trial settings due to the rarity of these diseases. In the relapsed and refractory setting, novel approaches such as anti-CD19 chimeric antigen receptor T cells and antibodies against CD19 have demonstrated high efficacy in this subgroup. Recently, genomic studies have made much progress in investigating some of the molecular underpinnings that drive their lymphomagenesis and have paved the way for testing additional novel approaches.

Phase 1b study of the BET protein inhibitor RO6870810 with venetoclax and rituximab in patients with diffuse large B-cell lymphoma

Bromodomain and extraterminal (BET) proteins are transcriptional activators for multiple oncogenic processes in diffuse large B-cell lymphoma (DLBCL), including MYC, BCL2, E2F, and toll-like receptor signaling. We report results of a phase 1b dose-escalation study of the novel, subcutaneous BET inhibitor RO6870810 (RO) combined with the BCL-2 inhibitor venetoclax, and rituximab, in recurrent/refractory DLBCL. RO was delivered for 14 days of a 21-day cycle, whereas venetoclax was delivered continuously. A 3 + 3 escalation design was used to determine the safety of the RO+venetoclax doublet; rituximab was added in later cohorts. Thirty-nine patients were treated with a median of 2.8 cycles (range, 1-11). Dose-limiting toxicities included grade 3 febrile neutropenia, grade 4 diarrhea, and hypomagnesemia for the doublet; and grade 3 hyperbilirubinemia and grade 4 diarrhea when rituximab was added. The doublet maximum tolerated dose (MTD) was determined to be 0.65 mg/kg RO+600 mg venetoclax; for RO+venetoclax+rituximab, the MTDs were 0.45 mg/kg, 600 mg, and 375 mg/m2, respectively. The most frequent grade 3 and 4 adverse events were neutropenia (28%) and anemia and thrombocytopenia (23% each). Responses were seen in all cohorts and molecular subtypes. Sustained decreases in CD11b on monocytes indicated pharmacodynamic activity of RO. Overall response rate according to modified Lugano criteria was 38.5%; 48% of responses lasted for ≥180 days. Complete response was observed in 8 patients (20.5%). Optimization of the treatment schedule and a better understanding of predictors of response would be needed to support broader clinical use. This trial is registered on www.clinicaltrials.gov as NCT03255096.

Immunotherapy for Diffuse Large B-Cell Lymphoma: Current Landscape and Future Directions

Simple Summary

Immunotherapy has played a pivotal role in the management of relapsed DLBCL. Stem cell transplant and CAR T-cell therapy are curative treatment modalities for relapsed disease. Despite this, a subset of patients continues to progress, and their outcomes remain dismal. Newer therapeutic options to optimize outcomes as well as minimize toxicity are warranted.

Abstract

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease. B-cell receptor (BCR) pathway is essential for malignant B-cell growth, survival, and proliferation. Various immune cells, including T-cells and macrophages in the tumor microenvironment (TME) contribute to tumor cell survival and pathogenesis of chemo-resistance. The presence of many targets on the malignant B-cells and in the TME has led to emergence of novel therapeutic agents. Stem cell transplant is the oldest treatment modality leveraging immune system in DLBCL. Subsequently, CD20 targeting monoclonal antibody and chimeric antigen receptor (CAR) T-cell therapy changed the treatment landscape of DLBCL. Recently, multiple novel immunotherapeutic agents have been added in the armamentarium for the management of DLBCL, and many are under development. In this review article, we will review latest updates of immunotherapeutic agents in the management of DLBCL.

Economic burden in treated Japanese patients with relapsed/refractory large B-cell lymphoma

Aim: To understand the economic burden of relapsed and refractory large B-cell lymphoma patients in Japan treated with salvage chemotherapy. Patients & methods: Patients who received systemic therapy after first-line treatment were analyzed to assess its associated cost and resource use using a retrospective claims database. The impact of COVID-19 was assessed separately. Results & conclusion: This study identified 2927 and 1085 patients in the second- (2L) and third-line (3L) cohorts. The median ages for the 2L and 3L cohorts were 71 and 70 years, respectively, with Charlson Comorbidity Score of 3. A majority of the patients had limited stem cell transplant due to advanced age. Median lengths of inpatient stay for the 2L and 3L cohorts were 118 and 116 days, respectively. The majority of costs were attributed to inpatient costs, and limited COVID-19 impact was observed in this study.

Venetoclax with dose-adjusted EPOCH-R as initial therapy for patients with aggressive B-cell lymphoma: a single-arm, multicentre, phase 1 study

BACKGROUND

Dose-adjusted EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab) is a front-line treatment for patients with aggressive B-cell lymphomas. Bcl-2 is associated with chemoresistance due to BCL2 gene rearrangement or protein overexpression and is antagonised by venetoclax. We aimed to assess the safety of venetoclax with dose-adjusted EPOCH-R as initial therapy in aggressive B-cell lymphoma.

METHODS

We conducted a single-arm, phase 1 study across seven treatment centres in the USA. Eligible patients were aged 18-80 years with histologically confirmed, previously untreated diffuse large B-cell lymphoma, transformed indolent non-Hodgkin lymphoma, high-grade B-cell lymphoma with double-hit or not otherwise specified, or primary mediastinal B-cell lymphoma, with Ann Arbor stage II-IV and Eastern Cooperative Oncology Group performance status of 0-2. Participants received six cycles of oral venetoclax 400 mg, 600 mg, or 800 mg once daily for 10 days per cycle with dose-adjusted EPOCH-R (one cycle every 3 weeks; baseline doses were intravenous rituximab 375 mg/m² on day 1, intravenous etoposide 50 mg/m² on days 1-4, oral prednisone 60 mg/m² twice daily on days 1-5, intravenous vincristine 0·4 mg/m² on days 1-4, intravenous cyclophosphamide 750 mg/m² on day 5, and intravenous doxorubicin 10 mg/m² on days 1-4). A subsequent cohort received venetoclax 600 mg once daily for 5 days per cycle. The primary endpoints were the maximum tolerated dose, dose-limiting toxicities, and the recommended phase 2 dose of venetoclax. Analyses were done per protocol. This trial is registered with ClinicalTrials.gov, NCT03036904, and enrolment is now closed.

FINDINGS

Between Feb 3, 2017, and June 4, 2019, 34 patients were assessed for eligibility, and 30 were enrolled and received venetoclax with dose-adjusted EPOCH-R. The median patient age was 64·0 years (IQR 51·6-69·4). The maximum tolerated dose was 800 mg for 10 days and the established recommended phase 2 dose was 600 mg for 5 days due to tolerability for treatment duration. One (3%) of 30 patients had a dose-limiting toxicity in cycle one (grade 4 thrombocytopenia with 800 mg dose). The most common grade 3-4 adverse events were cytopenias (28 [93%] of 30 patients); febrile neutropenia occurred in 19 (63%) patients. Grade 3-4 non-haematological adverse events included hypophosphataemia (n=10), hypokalaemia (n=7), and hyperglycaemia (n=5). Serious adverse events included infection (n=7) and gastrointestinal toxicities including abdominal pain (n=3), colonic perforation (n=1), and small intestinal obstruction (n=1). There was one treatment-related death (sepsis). Overall response rate was 96·7% (95% CI 82·8-99·9); 28 (93·3% [77·9-99·2]) of 30 patients had complete response and one (3·3% [0·1-17·2]) had a partial response.

INTERPRETATION

Venetoclax with dose-adjusted EPOCH-R showed an acceptable safety profile at the recommended phase 2 dose and had encouraging preliminary activity in this population at high risk of adverse outcomes, and is worthy of further study. The combination is being investigated in Alliance 051701 (NCT03984448).

FUNDING

Genentech.

Analysis of real-world data in patients with relapsed/refractory diffuse large B cell lymphoma who received salvage chemotherapy in the rituximab era

Although the overall clinical outcome of patients with diffuse large B cell lymphoma (DLBCL) has significantly improved, some patients still experience relapsed/refractory disease. In the rituximab era, real-world data about relapsed/refractory DLBCL are limited. To clarify the clinical outcome and prognostic factors in these patients, we conducted a retrospective analysis using data from the population-based Osaka Cancer Registry (OCR) from 2010 to 2015. In total, 189 adult patients aged up to 70 years who received CHOP or a CHOP-like regimen in combination with rituximab, as well as a subsequent second-line therapy, were included in the analysis. The median age was 63 years (range, 24-70). Age (> 63 years), the duration of first progression-free survival (PFS), and the use of rituximab in the second-line chemotherapy were prognostic factors for overall survival (OS) after the second-line treatment. In this cohort, 48 and 11 patients received autologous and allogeneic hematopoietic stem cell transplantation (HSCT), respectively. The probabilities of 3-year OS after autologous and allogeneic HSCT were 55.7% and 18.2%, respectively. In conclusion, we found that the clinical outcome of patients with relapsed/refractory DLBCL in the rituximab era was unsatisfactory. Further improvements in treatment strategies, including novel agents, are needed.

A new conditioning regimen with chidamide, cladribine, gemcitabine and busulfan significantly improve the outcome of high-risk or relapsed/refractory non-Hodgkin's lymphomas

Previous studies highlight the need for a more active conditioning therapy in high-risk or refractory and relapsed lymphomas. Our preclinical research shows that histone deacetylase inhibitors, such as either vorinostat or chidamide, sensitize lymphoma cells to the cytotoxic combination of cladribine, gemcitabine and busulfan, leading to cell apoptosis. To evaluate the efficacy of this chidamide-cladribine-gemcitabine-busulfan (ChiCGB) combination as a new conditioning therapy, we conducted a Phase II trial, as described here. Patients with high-risk, relapsed/refractory lymphomas received ChiCGB as conditioning therapy, after transplantation with autologous peripheral stem cells. The sample comprised 105 patients in total: 60 with B-cell non-Hodgkin lymphomas (B-NHL) and 45 with T-cell or natural killer/T-cell lymphoma (NK/T). All patients eventually achieved full hematopoietic recovery. Neutrophils and platelets were engrafted at a median of 10 days (8-14) and 13 days (8-38), respectively. There was no transplant-related mortality within 100 days of transplant. Neutropenic fever, mucositis and atopic dermatitis were the observed nonhematologic toxicities. At a median follow-up of 35.4 months, 80.6% of the patients presented with no tumor progression, and the overall survival (OS) reached as high as 86.1%. Concerning the OS rate, 94.5% of patients with B-NHL and 75.4% of patients with T-cell or NK/T lymphomas survived. These findings demonstrate the safety and validity of the proposed combined therapy for high-risk and refractory/relapsed lymphomas. Our study was registered on the Clinical Trial Registry (clinicaltrials.gov, NCT03151876).

Treatment resistance in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a highly heterogeneous disease and represents the most common subtype of lymphoma. Although 60-70% of all patients can be cured by the current standard of care in the frontline setting, the majority of the remaining patients will experience treatment resistance and have a poor clinical outcome. Numerous efforts have been made to improve the efficacy of the standard regimen by, for example, dose intensification or adding novel agents. However, these results generally failed to demonstrate significant clinical benefits. Hence, understanding treatment resistance is a pressing need to optimize the outcome of those patients. In this Review, we first describe the conceptual sources of treatment resistance in DLBCL and then provide detailed and up-to-date molecular insight into the mechanisms of resistance to the current treatment options in DLBCL. We lastly highlight the potential strategies for rationally managing treatment resistance from both the preventive and interventional perspectives.

Pyruvate dehydrogenase kinase 4-mediated metabolic reprogramming is involved in rituximab resistance in diffuse large B-cell lymphoma by affecting the expression of MS4A1/CD20

Diffuse large B cell lymphoma (DLBCL) heterogeneity promotes recurrence and anti‐CD20‐based therapeutic resistance. Previous studies have shown that downregulation of MS4A1/CD20 expression after chemoimmunotherapy with rituximab leads to rituximab resistance. However, the mechanisms of CD20 loss remain unknown. We identified that pyruvate dehydrogenase kinase 4 (PDK4) is markedly elevated in DLBCL cells derived from both patients and cell lines with R‐CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) resistance. We found that overexpression of PDK4 in DLBCL cells resulted in cell proliferation and resistance to rituximab in vitro and in vivo. Furthermore, loss of PDK4 expression or treatment with the PDK4 inhibitor dichloroacetate was able to significantly increase rituximab‐induced cell apoptosis in DLBCL cells. Further studies suggested PDK4 mediates a metabolic shift, in that the main energy source was changed from oxidative phosphorylation to glycolysis, and the metabolic changes could play an important role in rituximab resistance. Importantly, by knocking down or overexpressing PDK4 in DLBCL cells, we showed that PDK4 has a negative regulation effect on MS4A1/CD20 expression. Collectively, this is the first study showing that targeting PDK4 has the potential to overcome rituximab resistance in DLBCL.

Is autologous transplant in relapsed DLBCL patients achieving only a PET+ PR appropriate in the CAR T-cell era?

For relapsed chemosensitive diffuse large B-cell lymphoma (DLBCL), consolidation with autologous hematopoietic cell transplantation (auto-HCT) is a standard option. With the approval of anti-CD19 chimeric antigen receptor T cells in 2017, the Center for International Blood and Marrow Transplant Research (CIBMTR) reported a 45% decrease in the number of auto-HCTs for DLBCL in the United States. Using the CIBMTR database, we identified 249 relapsed DLBCL patients undergoing auto-HCT from 2003 to 2013 with a positive positron emission tomography/computed tomography (PET/CT)+ partial response prior to transplant were identified. The study cohort was divided into 2 groups: early chemoimmunotherapy failure (ECF), defined as patients with primary refractory disease (PRefD) or relapse within 12 months of diagnosis and late chemoimmunotherapy failure, defined as patients relapsing after ≥12 months. Primary outcome was overall survival (OS). Secondary outcomes included progression-free survival (PFS) and relapse. A total of 182 patients had ECF, whereas 67 did not. Among ECF cohort, 79% had PRefD. The adjusted 5-year probabilities for PFS and OS (ECF vs no ECF) were not different: 41% vs 41% (P = .93) and 51% vs 63% (P = .09), respectively. On multivariate analysis, ECF patients had an increased risk for death (hazard ratio, 1.61; 95% confidence interval, 1.05-2.46; P = .03) but not for PFS or relapse. In conclusion, for relapsed chemosensitive DLBCL patients with residual PET/CT+ disease prior to auto-HCT, the adjusted 5-year PFS (41%) was comparable, irrespective of time to relapse. These data support ongoing application of auto-HCT in chemosensitive DLBCL.

Comparison of the Effectiveness and Safety of the Oral Selective Inhibitor of Nuclear Export, Selinexor, in Diffuse Large B Cell Lymphoma Subtypes

BACKGROUND

The SADAL study evaluated oral selinexor in patients with relapsed and/or refractory diffuse large B-cell lymphoma (DLBCL) after at least 2 prior lines of systemic therapy. In this post-hoc analysis, we analyzed the outcomes of the SADAL study by DLBCL subtype to determine the effects of DLBCL subtypes on efficacy and tolerability of selinexor.

PATIENTS AND METHODS

Data from 134 patients in SADAL were analyzed by DLBCL subtypes for overall response rate (ORR), overall survival (OS), duration of treatment response, progression-free survival, and adverse events rate.

RESULTS

ORR in the entire cohort was 29.1%, and similar in patients with germinal center (GCB) versus non-GCB DLBCL (31.7% vs. 24.2%, P = 0.45); transformed DLBCL showed a trend towards higher ORR than de novo DLBCL: 38.7% vs. 26.2% (P = 0.23). Despite similar prior treatment regimens and baseline characteristics, patients with DLBCL and normal C-MYC/BCL-2 protein expression levels had a significantly higher ORR (46.2% vs.14.8%, P = 0.012) and significantly longer OS (medians 13.7 vs. 5.1 months, hazard ratio 0.43 [95% CI, 0.23-0.77], P = 0.004) as compared with those whose DLBCL had C-MYC and BCL-2 overexpression. Among patients who had normal expression levels of either C-MYC or BCL-2 and baseline hemoglobin levels ≥ 10g/dL, ORR was 51.5% (n = 47), with median OS of 15.5 months and median PFS of 4.6 months. Similar rates of adverse events were noted in all subgroups.

CONCLUSIONS

Overall, single agent oral selinexor showed strong responses in patients with limited treatment alternatives regardless of germinal center B-cell type or disease origin.

Polatuzumab vedotin as a salvage and bridging treatment in relapsed or refractory large B-cell lymphomas

The antibody-drug conjugate polatuzumab vedotin (pola) has recently been approved in combination with bendamustine and rituximab (pola-BR) for patients with refractory or relapsed (r/r) large B-cell lymphoma (LBCL). To investigate the efficacy of pola-BR in a real-world setting, we retrospectively analyzed 105 patients with LBCL who were treated in 26 German centers under the national compassionate use program. Fifty-four patients received pola as a salvage treatment and 51 patients were treated with pola with the intention to bridge to chimeric antigen receptor (CAR) T-cell therapy (n = 41) or allogeneic hematopoietic cell transplantation (n = 10). Notably, patients in the salvage and bridging cohort had received a median of 3 prior treatment lines. In the salvage cohort, the best overall response rate was 48.1%. The 6-month progression-free survival and overall survival (OS) was 27.7% and 49.6%, respectively. In the bridging cohort, 51.2% of patients could be successfully bridged with pola to the intended CAR T-cell therapy. The combination of pola bridging and successful CAR T-cell therapy resulted in a 6-month OS of 77.9% calculated from pola initiation. Pola vedotin-rituximab without a chemotherapy backbone demonstrated encouraging overall response rates up to 40%, highlighting both an appropriate alternative for patients unsuitable for chemotherapy and a new treatment option for bridging before leukapheresis in patients intended for CAR T-cell therapy. Furthermore, 7 of 12 patients with previous failure of CAR T-cell therapy responded to a pola-containing regimen. These findings suggest that pola may serve as effective salvage and bridging treatment of r/r LBCL patients.

The Incidence and Treatment Response of Double Expression of MYC and BCL2 in Patients with Diffuse Large B-Cell Lymphoma: A Systematic Review and Meta-Analysis

MYC/BCL2 protein co-expression (i.e., double expressor) has been shown to be a negative predictor of outcome in diffuse large B-cell lymphoma (DLBCL). We aimed to establish the incidence of double expressor status in patients with de novo DLBCL and identify the predictive value of this biomarker on treatment response through systematic review and meta-analysis. PubMed and Embase were searched for studies published through December 2019 that reported proportions of double expressor DLBCL. The pooled proportions of MYC and BCL2 expression, both alone and in combination, were computed using the inverse variance method for calculating weights and by the DerSimonian-Laird method. The pooled odds ratios (ORs) of complete remission (CR) rate were calculated, and meta-regression analysis was conducted to explore heterogeneity. Forty-one studies (7054 patients) were included. The pooled incidence of double expressor status in DLBCL was 23% (95% confidence interval [CI], 20-26%), with an adjusted estimate of 31% (95% CI, 27-36%). Neither MYC/BCL2 protein cutoff values, race, mean, or median age of included patients, or overall study quality was a significant factor of heterogeneity (p ≥ 0.20). Cases without double expressor status demonstrated a higher probability of CR to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone treatment (OR, 2.69; 95% CI, 1.55-4.67). Our results reaffirm the predictive power of this important biomarker.

Clinicopathological analysis of primary refractory diffuse large B-cell lymphoma treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone chemoimmunotherapy

Background

Approximately 15% of patients with diffuse large B‐cell lymphoma (DLBCL) experience refractory or early relapsed disease after initial rituximab‐containing chemoimmunotherapy is regarded as a primary refractory disease. Although the standard treatment for relapsed DLBCL is high‐dose chemotherapy and autologous stem cell transplantation (HDC‐ASCT), the efficacy of this approach for primary refractory DLBCL is not well understood. We aimed to investigate the clinicopathological characteristics and outcomes of patients with primary refractory DLBCL.

Methods

Sixty‐nine consecutive patients with primary refractory DLBCL who were treated at our institution were categorized as partial responders (partial response to rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone [R‐CHOP] or relapse within 6 months of R‐CHOP) (n = 41) or primary progressors (no response to R‐CHOP) (n = 28). Survival curves were constructed using the Kaplan–Meier method and compared using the log‐rank test.

Results

At initial diagnosis, 70% of patients had Ann Arbor stage III/IV disease, 56% had non‐germinal center B‐cell‐like type DLBCL, and 42% had double‐expressor lymphoma (MYC and BCL2 expression). The 3‐year overall survival rate was significantly poorer in the primary progressors group than in the partial responders’ group (15% vs. 48%, p < 0.001). Four of 17 patients treated with HDC‐ASCT were primary progressors; only one patient survived without relapse. Although double‐expressor lymphoma status did not significantly impact overall survival among all patients (p = 0.794), it was identified as an independent poor prognostic factor in HDC‐ASCT‐treated patients (p = 0.002).

Conclusions

We identified a subgroup of patients with primary refractory DLBCL who may not benefit from current treatment strategies. Further treatment development is needed to improve the outcomes of these patients.

Genome instability and lymphoma

Lymphoma is one of the most common malignant tumor of the hematologic system. The genome instability is not only an important molecular basis for the development of lymphoma, but also has important value in the diagnosis and prognosis of lymphoma. There are 2 types of genome instability: Microsatellite instability (MSI/MIN) at gene level and chromosomal instability at chromosome level. Through the study on genes associated with lymphoma, the unstable genes associated with lymphoma could be found, meanwhile the mechanism of its occurrence and development of lymphoma could be explored, and the important basis of molecular biology could also be provided in the field of current hot lymphoma precision medical research.

PiggyBac-Generated CAR19-T Cells Plus Lenalidomide Cause Durable Complete Remission of Triple-Hit Refractory/Relapsed DLBCL: A Case Report

MYC/BCL2/BCL6 triple-hit lymphoma (THL) is an uncommon subset of high-grade B-cell lymphoma with aggressive clinical behavior and poor prognosis. TP53 mutation is an independently poor progonistic indicator in patients with THL, hence novel therapeutic strategies are needed for these patients. CD19-directed chimeric antigen receptor(CAR19)-T cell therapy has shown promising efficacy for relapsed/refractory diffuse large B cell lymphoma (RR DLBCL), but the majority of CAR19-T cell products to date have been manufactured using viral vectors. PiggyBac transposon system, with an inclination to memory T cells, offers a more convenient and economical alternative for transgene delivery. We herein report the first case of triple-hit RR DLBCL with TP53 mutation who was treated with piggyBac-generated CAR19-T cells and accompanied by grade 2 cytokine release syndrome. The patient obtained a complete remission (CR) in the 2nd month post-infusion and demanded maintenance therapy. Whether maintenance therapy is favorable and how to administrate it after CAR-T cell infusion remain controversial. Preclinical studies demonstrated that lenalidomide could enhance antitumor activity of CAR19-T cells. Therefore, we pioneered oral lenalidomide after CAR19-T therapy in the patient from the 4th month, and he discontinued after one cycle due to side effects. The patient has still kept sustained CR for over 24 months. Our case have firstly demonstrated the feasibility, preliminary safety and efficacy of piggyBac-produced CAR19-T cell therapy in triple-hit lymphoma. The innovative combination with lenalidomide warrants further investigation. Our findings shed new light on the possible solutions to improve short-term relapse after CAR19-T cell therapy in RR DLBCL. ChiCTR, number ChiCTR1800018111.