Response to second-line therapy defines the potential for cure in patients with recurrent diffuse large B-cell lymphoma: implications for the development of novel therapeutic strategies

Bispecific CAR-T cells targeting CD19/20 in patients with relapsed or refractory B cell non-Hodgkin lymphoma: a phase I/II trial

Non-Hodgkin lymphoma (NHL) is a common malignancy in the hematologic system, and traditional therapy has limited efficacy for people with recurrent/refractory NHL (R/R NHL), especially for patients with diffuse large B cell lymphoma (DLBCL). Chimeric antigen receptor (CAR) T-cell therapy is a novel and effective immunotherapy strategy for R/R hematopoietic malignancies, but relapses can occur due to the loss of CAR-T cells in vivo or the loss of antigen. One strategy to avoid antigen loss after CAR-T cell therapy is to target one more antigen simultaneously. Tandem CAR targeting CD19 and CD22 has demonstrated the reliability of tandem CAR-T cell therapy for R/R B-ALL. This study explores the therapeutic potential of tandem CD19/20 CAR-T in the treatment of R/R B cell NHL. The efficacy and safety of autologous CD19/20 CAR-T cells in eleven R/R B cell NHL adult patients were evaluated in an open-label, single-arm trial. Most patients achieved complete response, exhibiting the efficacy and safety of tandem CD19/20 CAR-T cells. The TCR repertoire diversity of CAR-T cells decreased after infusion. The expanded TCR clones in vivo were mainly derived from TCR clones that had increased expression of genes associated with immune-related signaling pathways from the infusion product (IP). The kinetics of CAR-T cells in vivo were linked to an increase in the expression of genes related to immune response and cytolysis/cytotoxicity.

Molecular Subtypes and the Role of TP53 in Diffuse Large B-Cell Lymphoma and Richter Syndrome

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid malignancy and a heterogeneous entity comprised of several biologically distinct subtypes. Recently, novel genetic classifications of DLBCL have been resolved based on common mutational patterns indicative of distinct pathways of transformation. However, the complicated and costly nature of the novel classifiers has precluded their inclusion into routine practice. In view of this, the status of the TP53 gene, which is mutated or deleted in 20-30% of the cases, has emerged as an important prognostic factor for DLBCL patients, setting itself apart from other predictors. TP53 genetic lesions are particularly enriched in a genetic subtype of DLBCL that shares genomic features with Richter Syndrome, highlighting the possibility of a subset of DLBCL arising from the transformation of an occult chronic lymphocytic leukemia-like malignancy, such as monoclonal B-cell lymphocytosis. Patients with TP53-mutated DLBCL, including those with Richter Syndrome, have a particularly poor prognosis and display inferior responses to standard chemoimmunotherapy regimens. The data presented in this manuscript argue for the need for improved and more practical risk-stratification models for patients with DLBCL and show the potential for the use of TP53 mutational status for prognostication and, in prospect, treatment stratification in DLBCL.

Two-year follow-up of lisocabtagene maraleucel in relapsed or refractory large B-cell lymphoma in TRANSCEND NHL 001

ABSTRACT

Lisocabtagene maraleucel (liso-cel) demonstrated significant efficacy with a manageable safety profile as third-line or later treatment for patients with relapsed or refractory (R/R) large B-cell lymphoma (LBCL) in the TRANSCEND NHL 001 study. Primary end points were adverse events (AEs), dose-limiting toxicities, and objective response rate (ORR) per independent review committee. Key secondary end points were complete response (CR) rate, duration of response (DOR), progression-free survival (PFS), and overall survival (OS). After 2-year follow-up, patients could enroll in a separate study assessing long-term (≤15 years) safety and OS. Liso-cel-treated patients (N = 270) had a median age of 63 years (range, 18-86 years) and a median of 3 prior lines (range, 1-8) of systemic therapy, and 181 of them (67%) had chemotherapy-refractory LBCL. Median follow-up was 19.9 months. In efficacy-evaluable patients (N = 257), the ORR was 73% and CR rate was 53%. The median (95% confidence interval) DOR, PFS, and OS were 23.1 (8.6 to not reached), 6.8 (3.3-12.7), and 27.3 months (16.2-45.6), respectively. Estimated 2-year DOR, PFS, and OS rates were 49.5%, 40.6%, and 50.5%, respectively. In the 90-day treatment-emergent period (N = 270), grade 3 to 4 cytokine release syndrome and neurological events occurred in 2% and 10% of patients, respectively. The most common grade ≥3 AEs in treatment-emergent and posttreatment-emergent periods, respectively, were neutropenia (60% and 7%) and anemia (37% and 6%). Liso-cel demonstrated durable remissions and a manageable safety profile with no new safety signals during the 2-year follow-up in patients with R/R LBCL. These trials were registered at www.ClinicalTrials.gov as #NCT02631044 and #NCT03435796.

Chimeric antigen receptor T-cell therapy in hematologic malignancies: Successes, challenges, and opportunities

The success of chimeric antigen receptor T-cell (CAR-T) therapy in hematologic malignancies has realized a longstanding effort toward harnessing the immune system to fight cancer in a truly personalized fashion. Second generation chimeric antigen receptors (CAR) incorporating co-stimulatory molecules like 4-1BB or CD28 were able to overcome some of the hindrances with initial CAR constructs resulting in efficacious products. Many second-generation CAR-T products have been approved in the treatment of relapsed/refractory hematologic malignancies including multiple myeloma (MM), non-Hodgkin lymphoma (NHL), and acute lymphoblastic leukemia. However, challenges remain in optimizing the manufacturing, timely access, limiting the toxicity from CAR-T infusions and improving sustainability of responses derived with CAR-T therapy. Here, we summarize the clinical trial data leading to approval CAR-T therapies in MM and NHL, discuss the limitations with current CAR-T therapy strategies and review emerging strategies for overcoming these limitations.

XPO1 Enables Adaptive Regulation of mRNA Export Required for Genotoxic Stress Tolerance in Cancer Cells

Exportin-1 (XPO1), the main soluble nuclear export receptor in eukaryotic cells, is frequently overexpressed in diffuse large B-cell lymphoma (DLBCL). A selective XPO1 inhibitor, selinexor, received approval as single agent for relapsed or refractory (R/R) DLBCL. Elucidating the mechanisms by which XPO1 overexpression supports cancer cells could facilitate further clinical development of XPO1 inhibitors. We uncovered here that XPO1 overexpression increases tolerance to genotoxic stress, leading to a poor response to chemoimmunotherapy. Upon DNA damage induced by MYC expression or exogenous compounds, XPO1 bound and exported EIF4E and THOC4 carrying DNA damage repair mRNAs, thereby increasing synthesis of DNA damage repair proteins under conditions of increased turnover. Consequently, XPO1 inhibition decreased the capacity of lymphoma cells to repair DNA damage and ultimately resulted in increased cytotoxicity. In a phase I clinical trial conducted in R/R DLBCL, the combination of selinexor with second-line chemoimmunotherapy was tolerated with early indication of efficacy. Overall, this study reveals that XPO1 overexpression plays a critical role in the increased tolerance of cancer cells to DNA damage while providing new insights to optimize the clinical development of XPO1 inhibitors.

SIGNIFICANCE

XPO1 regulates the dynamic ribonucleoprotein nuclear export in response to genotoxic stress to support tolerance and can be targeted to enhance the sensitivity of cancer cells to endogenous and exogenous DNA damage. See related commentary by Knittel and Reinhardt, p. 3.

Recent advances in CAR T-cell therapy for lymphoma in China

Lymphoma is a hematologic malignancy which mainly consists of Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Although systemic chemotherapy, radiotherapy, and other advanced therapeutics, including rituximab or immune checkpoint inhibitors, have improved the prognosis in recent decades, there are still a number of patients with relapsed or refractory (R/R) lymphoma with a poor prognosis. Chimeric antigen receptor (CAR) T-cell therapy has provided a curative option for patients with relapsed or refractory lymphoma. Numerous clinical trials have been conducted worldwide and presented inspiring results that give insight into this breakthrough therapy. The development of cancer cell therapy in China has been rapid in the past years and dominates the field with the USA. This review aims to summarize the published results of CAR T-cell therapy alone or in combination with other therapies in mainland China, both in R/R NHL and R/R HL.

Clinical outcomes in transplant-eligible patients with relapsed or refractory diffuse large B-cell lymphoma after second-line salvage chemotherapy: A retrospective study

OBJECTIVE

The prognosis of patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) is poor. Although patients who fail first-line salvage chemotherapy are candidates for second-line salvage chemotherapy, the optimal treatment strategy for these patients has not yet been established.

METHODS

The present, single-center, retrospective study included transplant-eligible patients with R/R DLBCL who received second-line salvage chemotherapy with curative intent.

RESULTS

Seventy-six patients with R/R DLBCL received second-line salvage chemotherapy. Eighteen (23.7%) patients were responders to the first-line salvage chemotherapy. The overall response rate was 39.5%, and overall survival (OS) was significantly longer in patients who responded to second-line salvage chemotherapy than those who did not. Forty-one patients who proceeded to potentially curative treatment (autologous hematopoietic stem cell transplantation [ASCT], chimeric antigen receptor [CAR] T-cell therapy, or allogeneic hematopoietic stem cell transplantation) had a better prognosis than those who did not. Among the 46 patients who failed to respond to the second-line salvage regimen, only 18 (39.1%) could proceed to the curative treatments. However, among the 30 patients who responded to the second-line salvage regimen, 23 (76.7%) received one of the potentially curative treatments. Among 34 patients who received CAR T-cell therapy, OS was significantly longer in those who responded to salvage chemotherapy immediately prior to CAR T-cell therapy than in those who did not respond. In contrast, the number of prior lines of chemotherapy was not identified as a statistically significant prognostic factor of survival. No significant difference was detected in OS between patients receiving ASCT and those receiving CAR T-cell therapy after the response to second-line salvage chemotherapy.

DISCUSSION

In this study, we demonstrated that chemosensitivity remained a crucial factor in predicting survival outcomes following CAR T-cell therapy irrespective of the administration timing, and that both ASCT and CAR T-cell therapy were acceptable after the response to second-line salvage chemotherapy.

Epigenetic priming improves salvage chemotherapy in diffuse large B-cell lymphoma via endogenous retrovirus-induced cGAS-STING activation

BACKGROUND

Although most patients with diffuse large B-cell lymphoma (DLBCL) achieve complete remission after first-line rituximab-containing immunochemotherapy, up to 40% of patients relapse and require salvage therapy. Among those patients, a substantial proportion remain refractory to salvage therapy due to insufficient efficacy or intolerance of toxicities. A hypomethylating agent, 5-azacytidine, showed a chemosensitizing effect when primed before chemotherapy in lymphoma cell lines and newly diagnosed DLBCL patients. However, its potential to improve outcomes of salvage chemotherapy in DLBCL has not been investigated.

RESULTS

In this study, we demonstrated the mechanism of 5-azacytidine priming as a chemosensitizer in a platinum-based salvage regimen. This chemosensitizing effect was associated with endogenous retrovirus (ERV)-induced viral mimicry responses via the cGAS-STING axis. We found deficiency of cGAS impaired the chemosensitizing effect of 5-azacytidine. Furthermore, combining vitamin C and 5-azacytidine to synergistically activate STING could be a potential remedy for insufficient priming induced by 5-azacytidine alone.

CONCLUSIONS

Taken together, the chemosensitizing effect of 5-azacytidine could be exploited to overcome the limitations of the current platinum-containing salvage chemotherapy in DLBCL and the status of cGAS-STING has the potential to predict the efficacy of 5-azacytidine priming.

Recent Advances and Challenges in Cancer Immunotherapy

Simple Summary

Immunotherapy helps a person’s immune system to target tumor cells. Recent advances in cancer immunotherapy, including immune checkpoint inhibition, chimeric antigen receptor T-cell therapy and cancer vaccination, have changed the landscape of cancer treatment. These approaches have had profound success in certain cancer types but still fail in the majority of cases. This review will cover both successes and current challenges in cancer immunotherapy, as well as recent advances in the field of basic tumor immunology that will allow us to overcome resistance to existing treatments.

Abstract

Cancer immunotherapy has revolutionized the field of oncology in recent years. Harnessing the immune system to treat cancer has led to a large growth in the number of novel immunotherapeutic strategies, including immune checkpoint inhibition, chimeric antigen receptor T-cell therapy and cancer vaccination. In this review, we will discuss the current landscape of immuno-oncology research, with a focus on elements that influence immunotherapeutic outcomes. We will also highlight recent advances in basic aspects of tumor immunology, in particular, the role of the immunosuppressive cells within the tumor microenvironment in regulating antitumor immunity. Lastly, we will discuss how the understanding of basic tumor immunology can lead to the development of new immunotherapeutic strategies.

Assessment of Salvage Regimens Post CAR-T Cell Therapy for Patients with Diffuse Large B-Cell Lymphoma

BACKGROUND

Anti-CD19 chimeric antigen receptor T-cell therapy (CAR19) represents a critical treatment modality for patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). However, the majority of patients will subsequently experience disease progression following CAR19 and there is limited data assessing the best salvage regimen for these patients.

OBJECTIVE

To evaluate outcomes in DLBCL patients with progressive disease post CAR19 and to assess variables that predict response to salvage therapy.

STUDY DESIGN

We performed a retrospective analysis of all patients with DLBCL who received CAR19 at our institution from January 2018 to February 2021. Demographics, disease characteristics, best response to CAR19, date of relapse or progression, and first salvage therapy and response to salvage were also collected. We analyzed patients according to whether they responded to CAR19 (responders) or did not (non-responders). Salvage regimens were classified into 6 groups for analysis. Primary endpoints included overall survival (OS) and progression free survival (PFS), calculated using the Kaplan Meier method. Cox models were fit to evaluate the effect of prognostic factors.

RESULTS

Of the 120 patients who received CAR19 during the analysis period, 69 patients achieved a CR/PR to CAR19 (responders), 44 patients achieved SD/PD to CAR19, and 7 died before assessment (51 non-responders). 30 responders relapsed and 26 received salvage therapy, while 24 non-responders received salvage. The primary salvage regimens that were utilized included lenalidomide-based regimens (n=17, 34%), BTKi (n=10, 20%), checkpoint inhibitor based (n=7, 14%), chemo-immunotherapy (n=5, 10%), allo (n=5, 10%), and other (n=6, 12%). There was no significant difference in OS based on salvage regimen (p=0.4545). Responders who received salvage had significantly longer OS compared to non-responders (median OS not reached vs. 10.9 months; p=0.0187), and response to CAR19 and elevated lactate dehydrogenase (LDH) level at time of salvage treatment were the only two statistically significant prognostic factors after accounting for other variables.

CONCLUSION

Outcomes for responders to CAR19 are significantly better with salvage therapy as compared to non-responders to CAR19. There was no significant difference in outcomes seen based on salvage regimen in our study. Future research is needed to assess the best salvage regimen post CAR19 failure.

CAR T-cell therapy for B-cell lymphoma

Chimeric antigen receptor-modified (CAR) T-cell therapy targeting CD19 has revolutionized the treatment of relapsed or refractory B-cell lymphomas. Based on unprecedented response rates and durability of response in high risk B-cell lymphoma patients, anti-CD19 CAR T-cell therapy was rapidly approved by the FDA for a variety of lymphoma subtypes. Anti-CD19 CAR T-cell therapy is now considered standard of care for patients with relapsed or refractory (R/R) aggressive non-Hodgkin's Lymphoma (NHL) after 2 or more lines of therapy. Three second-generation anti-CD19 CAR T-cell products have been FDA approved for R/R aggressive B-cell lymphoma and FDA approval has been obtained for Mantle Cell Lymphoma and Follicular lymphoma as well. This has ensured broad access to CAR T-cell therapy for patients with NHL and new real-world trials have helped confirm feasibility of CAR T-cell therapy for a broad patient population. The emergence of CAR T-cell therapy will likely provide a new patient population who is status post anti-CD19 CAR T-cell therapy. Investigation of mechanisms of failure of CAR T-cell therapy and clinical trials to study strategies to address this are thus required. Here we provide a thorough review on the use of the FDA approved anti-CD19 CAR T-cell products axicabtagene ciloleucel, tisagenlecleucel, and lisocabtagene maraleucel in patients with indolent or aggressive B-cell lymphoma, and touch on mechanisms of failure of CAR T-cell therapy and potential approaches which are currently under investigation to address this.

Combination of Decitabine and a Modified Regimen of Cisplatin, Cytarabine and Dexamethasone: A Potential Salvage Regimen for Relapsed or Refractory Diffuse Large B-Cell Lymphoma After Second-Line Treatment Failure

Objective

The prognosis for patients with relapsed or refractory diffuse large B-cell lymphoma (R/R-DLBCL) after second-line treatment failure is extremely poor. This study prospectively observed the efficacy and safety of decitabine with a modified cisplatin, cytarabine, and dexamethasone (DHAP) regimen in R/R-DLBCL patients who failed second-line treatment.

Methods

Twenty-one R/R-DLBCL patients were enrolled and treated with decitabine and a modified DHAP regimen. The primary endpoints were overall response rate (ORR) and safety. The secondary endpoints were progression-free survival (PFS) and overall survival (OS).

Results

ORR reached 50% (complete response rate, 35%), five patients (25%) had stable disease (SD) with disease control rate (DCR) of 75%. Subgroup analysis revealed patients over fifty years old had a higher complete response rate compared to younger patients (P = 0.005), and relapsed patients had a better complete response rate than refractory patients (P = 0.031). Median PFS was 7 months (95% confidence interval, 5.1-8.9 months). Median OS was not achieved. One-year OS was 59.0% (95% CI, 35.5%-82.5%), and two-year OS was 51.6% (95% confidence interval, 26.9%-76.3%). The main adverse events (AEs) were grade 3/4 hematologic toxicities such as neutropenia (90%), anemia (50%), and thrombocytopenia (70%). Other main non-hematologic AEs were grade 1/2 nausea/vomiting (40%) and infection (50%). No renal toxicity or treatment-related death occurred.

Conclusion

Decitabine with a modified DHAP regimen can improve the treatment response and prognosis of R/R-DLBCL patients with good tolerance to AEs, suggesting this regimen has potential as a possible new treatment option for R/R-DLBCL patients after second-line treatment failure.

Clinical Trial Registration

ClinicalTrials.gov, identifier: NCT03579082.

Sequential intensive chemotherapy followed by autologous or allogeneic transplantation for refractory lymphoma

We evaluate the safety of bendamustine as a bridge to stem cell transplantation (SCT) in patients with relapsed/refractory lymphoma and residual disease after salvage therapy. Thirty-four subjects without complete responses (CR) received bendamustine 200 mg/m²/day for 2 days followed 14 days later by SCT. Sixteen subjects in partial remission (PR) with maximal FDG-PET SUVs ≤8 prior to bendamustine received autologous SCT, while 13 with suboptimal responses were allografted. Five subjects did not proceed to transplant. No bendamustine toxicities precluded transplantation and no detrimental effect on engraftment or early treatment-related mortality (TRM) was attributable to bendamustine. At 1 year, 75% of auto-recipients and 31% of allo-recipients were alive with CR. Two subjects in the autologous arm developed therapy-related myeloid neoplasia (t-MN). In conclusion, a bendamustine bridge to SCT can be administered without early toxicity to patients with suboptimal responses to salvage chemotherapy. However this approach may increase the risk of t-MN. (NCT02059239).Supplemental data for this article is available online at here.

Efficacy and safety of CD19 chimeric antigen receptor T cells in the treatment of 11 patients with relapsed/refractory B-cell lymphoma: a single-center study

Background

No effective treatment exist for patients with relapsed and refractory B-cell lymphoma, until the advent of anti-CD19 chimeric antigen receptor (CAR) T-cells. Therefore, this study aimed to explore the factors affecting the efficacy of anti-CD19 CAR T-cell and the adverse reactions of the therapy.

Methods

We recruited 11 patients with relapsed and refractory B-cell lymphoma. The number of anti-CD19 CAR T-cells, proliferation, and adverse reactions were recorded in detail, to explore the relationship between the factors affecting the efficacy of anti-CD19 CAR T-cell and the long-term survival of patients.

Results

The 11 patients in our study had a total overall response rate of 100%, after receiving anti-CD19 CAR T-cells. The median follow-up was 253 days (range, 130-1,017 days). The median overall survival (OS) and median progression-free survival (PFS) were not reached. After 3 months of treatment, the complete remission (CR) rate was 63.6% (7/11). As of December 7, 2019, 5 patients had maintained CR for a period exceeding 1 year, including 2 patients who had maintained CR for more than 1,000 days. The patients who received 3 or 4 lines of chemotherapy were more likely to have sustained remission than the patients who received <2 or >4 lines of chemotherapy. Each of the 4 patients in the study who had diffuse large B cell lymphoma (DLBCL) progression all had high myc protein expression (positive incidence: 30-80%). The incidence of Grade 2 cytokine release syndrome (CRS) was 36.4% (4/11), and Grade 3 CAR T-cell-related encephalopathy syndrome (CRES) was experienced by 1 patient. The occurrence of adverse reactions was not significantly related to the infusion dose, peak amplification time, or maximum copy amount. The immunoglobulin levels of the four patients who died showed a significant downward trend. Interleukin-1β (IL-1β), interferon-γ (IFN-γ), interleukin-10 (IL-10), and interleukin-17A (IL-17A) appeared to be associated with the occurrence of CRS and CRES.

Conclusions

Anti-CD19 CAR T-cell treatment is a new therapy for patients with relapsed and refractory B-cell lymphoma. Among the small sample size in this study, it demonstrated high efficiency and safety.

Economic Evaluation of Chimeric Antigen Receptor T-Cell Therapy by Site of Care Among Patients With Relapsed or Refractory Large B-Cell Lymphoma

Importance

Chimeric antigen receptor (CAR) T-cell therapies are currently administered at a limited number of cancer centers and are primarily delivered in an inpatient setting. However, variations in total costs associated with these therapies remain unknown.

Objective

To estimate the economic differences in the administration of CAR T-cell therapy by the site of care and the incidence of key adverse events.

Design, Setting, and Participants

A decision-tree model was designed to capture clinical outcomes and associated costs during a predefined period (from lymphodepletion to 30 days after the receipt of CAR T-cell infusion) to account for the potential incidence of acute adverse events and to evaluate variations in total costs for the administration of CAR T-cell therapy by site of care. Cost estimates were from the health care practitioner perspective and were based on data obtained from the literature and publicly available databases, including the Healthcare Cost and Utilization Project National Inpatient Sample, the Medicare Hospital Outpatient Prospective Payment System, the Medicare physician fee schedule, the Centers for Medicare and Medicaid Services Healthcare Common Procedure Coding System, and the IBM Micromedex RED BOOK. The model evaluated an average adult patient with relapsed or refractory large B-cell lymphoma who received CAR T-cell therapy in an academic inpatient hospital or nonacademic specialty oncology network.

Intervention

The administration of CAR T-cell therapy.

Main Outcomes and Measures

Total cost of the administration of CAR T-cell therapy by site of care. The costs associated with lymphodepletion, acquisition and infusion of CAR T cells, and management of acute adverse events were also examined.

Results

The estimated total cost of care associated with the administration of CAR T-cell therapy was $454 611 (95% CI, $452 466-$458 267) in the academic hospital inpatient setting compared with $421 624 (95% CI, $417 204-$422 325) in the nonacademic specialty oncology network setting, for a difference of $32 987. After excluding the CAR T-cell acquisition cost, hospitalization and office visit costs were $53 360 (65.3% of the total cost) in academic inpatient hospitals and $23 526 (48.4% of the total cost) in nonacademic specialty oncology networks. The administration of CAR T-cell therapy in nonacademic specialty oncology networks was associated with a $29 834 (55.9%) decrease in hospitalization and office visit costs and a $3154 (20.1%) decrease in procedure costs.

Conclusions and Relevance

The potential availability of CAR T-cell therapies that are associated with a lower incidence of adverse events and are suitable for outpatient administration may reduce the total costs of care by enabling the use of these therapies in nonacademic specialty oncology networks.

Assessment of epigenetic mechanisms and DNA double-strand break repair using laser micro-irradiation technique developed for hematological cells

Background

Certain tumors rely heavily on their DNA repair capability to survive the DNA damage induced by chemotherapeutic agents. Therefore, it is important to monitor the dynamics of DNA repair in patient samples during the course of their treatment, in order to determine whether a particular drug regimen perturbs the DNA repair networks in cancer cells and provides therapeutic benefits. Quantitative measurement of proteins and/or their posttranslational modification(s) at DNA double strand breaks (DSBs) induced by laser microirradiation provides an applicable diagnostic approach to examine DNA repair and its dynamics. However, its use is restricted to adherent cell lines and not employed in suspension tumor cells that include the many hematological malignancies.

Methods

Here, we report the development of an assay to laser micro-irradiate and quantitatively measure DNA repair transactions at DSB sites in normal mononuclear cells and a variety of suspension leukemia and lymphoma cells including primary patient samples.

Findings

We show that global changes in the H3K27me3-ac switch modulated by inhibitors of Class I HDACs, EZH2 methyltransferase and (or) H3K27me3 demethylases do not reflect the dynamic changes in H3K27me3 that occur at double-strand break sites during DNA repair.

Interpretation

Results from our mechanistic studies and proof-of-principle data with patient samples together show the effectiveness of using the modified micro-laser-based assay to examine DNA repair directly in suspension cancer cells, and has important clinical implications by serving as a valuable tool to assess drug efficacies in hematological cancer cells that grow in suspension.

Pixantrone, etoposide, bendamustine, rituximab (P[R]EBEN) as an effective salvage regimen for relapsed/refractory aggressive non-Hodgkin lymphoma-Polish Lymphoma Research Group real-life analysis

BACKGROUND

Despite a significant improvement in treatment outcomes, 30-40% of aggressive non-Hodgkin lymphomas (NHL) patients are refractory or relapse after the first line therapy. Half of them are not eligible to autologous stem cell transplantation (ASCT) due to failure of platinum-based salvage regimens. Pixantrone is conditionally approved in Europe in patients with R/R aggressive NHL failing at least 2 previous lines of therapy. Polish Lymphoma Research Group (PLRG) evaluated the efficacy and tolerability of P[R]EBEN combining pixantrone, etoposide, bendamustine with or without rituximab), a new regimen developed recently by Francesco d'Amore, in real-life experience.

METHODS

In this retrospective audit, we analyzed the data of consecutive 25 R/R NHL cases, treated with P[R]EBEN regimen in 9 PLRG centers. Safety and efficacy data, including adverse reactions (AE), response rates, progression-free and overall survival (PFS and OS) were collected.

RESULTS

Overall response rate (ORR) to P[R]EBEN regimen was 68% (40% CR and 28% PR). Most patients responded, relatively early, by second cycle of therapy. P[R]EBEN was effective in 8 out of 15 patients (53%) refractory to previous platinum-based salvage regimens. In 4 patients (16%) stabilization of disease (SD) during therapy was observed and further 4 patients (16%) progressed during the treatment (PD). Response rates were higher in patients, chemosensitive to their prior regimen (ORR - 87.5%, including 50% CR). At the median follow-up of 7.5 months (range 1-16) the median PFS and OS were not reached. Projected PFS and OS at 12 months are 68% and 78% respectively. The P[R]EBEN regimen was well tolerated and most of patients received it as out-patients. AEs grade ≥3 occurred in 17 patients (68%). Most common grade 3-4 AEs were due to hematological toxicity with febrile neutropenia observed in 5 patients (20%). There were no episodes of septic deaths. Six patients (24%) died during treatment and follow-up period, all of them due to lymphoma progression.

CONCLUSION

Our data suggest good efficiency and tolerability of P[R]EBEN regimen as a rescue therapy in patients with R/R aggressive NHL.

Extracellular vesicles in DLBCL provide abundant clues to aberrant transcriptional programming and genomic alterations

The biological role of extracellular vesicles (EVs) in diffuse large B-cell lymphoma (DLBCL) initiation and progression remains largely unknown. We characterized EVs secreted by 5 DLBCL cell lines, a primary DLBCL tumor, and a normal control B-cell sample, optimized their purification, and analyzed their content. We found that DLBCLs secreted large quantities of CD63, Alix, TSG101, and CD81 EVs, which can be extracted using an ultracentrifugation-based method and traced by their cell of origin surface markers. We also showed that tumor-derived EVs can be exchanged between lymphoma cells, normal tonsillar cells, and HK stromal cells. We then examined the content of EVs, focusing on isolation of high-quality total RNA. We sequenced the total RNA and analyzed the nature of RNA species, including coding and noncoding RNAs. We compared whole-cell and EV-derived RNA composition in benign and malignant B cells and discovered that transcripts from EVs were involved in many critical cellular functions. Finally, we performed mutational analysis and found that mutations detected in EVs exquisitely represented mutations in the cell of origin. These results enhance our understanding and enable future studies of the role that EVs may play in the pathogenesis of DLBCL, particularly with regards to the exchange of genomic information. Current findings open a new strategy for liquid biopsy approaches in disease monitoring.

TP53 Arg72 as a favorable prognostic factor for Chinese diffuse large B-cell lymphoma patients treated with CHOP

Background

TP53 Arg72Pro (SNP rs1042522) is associated with risk of non-Hodgkin lymphoma (NHL). Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of NHL. However, the relationship between this SNP and prognosis of DLBCL in Asians is unknown.

Methods

Genotyping of TP53 Arg72Pro was done in 425 Chinese DLBCL patients. Two hundred and eighty-nine patients were treated with R-CHOP, and 136 patients received CHOP or CHOP-like as frontline regimen. Three hundred and ninety-six patients were assessable for the efficacy.

Results

Patients with Arg/Arg and Arg/Pro at codon 72 of TP53 had a higher complete response rate (61% vs. 44%, P = 0.007) than those with Pro/Pro. In the subgroup treated with CHOP or CHOP-like therapy, patients with Arg/Arg and Arg/Pro showed a higher 5-year overall survival (OS) rate than those with Pro/Pro (68.8% vs. 23.2%, P = 0.001). Multivariate Cox regression analysis revealed TP53 Arg72 as a favorable prognostic factor in this group. However, the combination of rituximab with CHOP significantly increased the 5-year OS rate of patients with Pro/Pro to 63%.

Conclusion

This study revealed TP53 Arg72 as a favorable prognostic factor for Chinese DLBCL patients treated with CHOP or CHOP-like as frontline therapy.

Therapeutic potential of SGN-CD19B, a PBD-based anti-CD19 drug conjugate, for treatment of B-cell malignancies

Patients with relapsed/refractory B-cell malignancies such as non-Hodgkin lymphoma (B-NHL) or acute lymphoblastic leukemia have a poor prognosis. Despite measurable clinical activity with new targeted therapies, many patients do not achieve a complete or durable response suggesting an opportunity to improve upon existing therapies. Here we describe SGN-CD19B, a pyrrolobenzodiazepine (PBD)-based anti-CD19 antibody drug conjugate (ADC) being investigated for treatment of B-cell malignancies, which has improved potency compared with other ADCs. CD19-expressing tumor cells rapidly internalize SGN-CD19B, and the released PBD drug induces DNA damage, resulting in G2/M cell cycle arrest and cell death. SGN-CD19B demonstrated activity against a broad panel of malignant B-cell lines and induced durable regressions in mice bearing xenografts derived from these B-cell malignancies. A single dose of SGN-CD19B induced durable regressions at 300 μg/kg (3 μg/kg drug equivalents); combination with rituximab decreased the curative dose to 100 μg/kg (1 μg/kg drug equivalents). These doses are significantly lower than the level of drug required with other ADC payloads. In cynomolgus monkeys, SGN-CD19B effectively depleted CD20+ B lymphocytes in peripheral blood and lymphoid tissues confirming that SGN-CD19B is pharmacodynamically active at well-tolerated doses. In summary, preclinical studies show SGN-CD19B is a highly active ADC, which releases a DNA cross-linking agent rather than a microtubule inhibitor. The distinct mechanism of action, broad potency, and potential to combine with rituximab suggest that SGN-CD19B may offer unique clinical opportunities in B-cell malignancies. A phase 1 clinical trial is in progress to investigate the therapeutic potential of SGN-CD19B in relapsed/refractory B-NHL. This trial was registered at www.clinicaltrials.gov as #NCT02702141.

A bioclinical prognostic model using MYC and BCL2 predicts outcome in relapsed/refractory diffuse large B-cell lymphoma

The objective of this study was to create a bioclinical model, based on clinical and molecular predictors of event-free and overall survival for relapsed/refractory diffuse large B-cell lymphoma patients treated on the Canadian Cancer Trials Group (CCTG) LY12 prospective study. In 91 cases, sufficient histologic material was available to create tissue microarrays and perform immunohistochemistry staining for CD10, BCL6, MUM1/IRF4, FOXP1, LMO2, BCL2, MYC, P53 and phosphoSTAT3 (pySTAT3) expression. Sixty-seven cases had material sufficient for fluorescent in situ hybridization (FISH) for MYC and BCL2. In addition, 97 formalin-fixed, paraffin-embedded tissue samples underwent digital gene expression profiling (GEP) to evaluate BCL2, MYC, P53, and STAT3 expression, and to determine cell-of-origin (COO) using the Lymph2Cx assay. No method of determining COO predicted event-free survival (EFS) or overall survival (OS). Factors independently associated with survival outcomes in multivariate analysis included primary refractory disease, elevated serum lactate dehydrogenase (LDH) at relapse, and MYC or BCL2 protein or gene expression. A bioclinical score using these four factors predicted outcome with 3-year EFS for cases with 0–1 vs. 2–4 factors of 55% vs. 16% (P<0.0001), respectively, assessing MYC and BCL2 by immunohistochemistry, 46% vs. 5% (P<0.0001) assessing MYC and BCL2 messenger ribonucleic acid (mRNA) by digital gene expression, and 42% vs. 21% (P=0.079) assessing MYC and BCL2 by FISH. This proposed bioclinical model should be further studied and validated in other datasets, but may discriminate relapsed/refractory diffuse large B-cell lymphoma (DLBCL) patients who could benefit from conventional salvage therapy from others who require novel approaches. The LY12 study; clinicaltrials.gov Identifier: 00078949.

CUDC-907 in relapsed/refractory diffuse large B-cell lymphoma, including patients with MYC-alterations: results from an expanded phase I trial

CUDC-907 is a first-in-class, oral small molecule inhibitor of both HDAC (class I and II) and PI3K (class Iα, β, and δ) enzymes, with demonstrated anti-tumor activity in multiple pre-clinical models, including MYC-driven ones. In this report, we present the safety and preliminary activity results of CUDC-907, with and without rituximab, in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL), with a particular focus on those with MYC-altered disease. Thirty-seven DLBCL patients were enrolled, 14 with confirmed MYC-altered disease. Twenty-five patients received monotherapy treatment, and 12 received the combination of CUDC-907 with rituximab. CUDC-907 monotherapy and combination demonstrated similar safety profiles consisting primarily of Grade 1/2 hematologic and gastrointestinal events. The most frequently reported Grade ≥3 treatment-related events were thrombocytopenia, neutropenia, diarrhea, fatigue, and anemia. Eleven responses (5 complete responses and 6 partial responses) were reported, for a response rate of 37% (11 out of 30) in evaluable patients [30% (11 out of 37) including all patients]. The objective response rate in evaluable MYC-altered DLBCL patients was 64% (7 out of 11; 4 complete responses and 3 partial responses), while it was 29% (2 out of 7) in MYC unaltered, and 17% (2 out of 12) in those with unknown MYC status. Median duration of response was 11.2 months overall; 13.6 months in MYC-altered patients, 6.0 months in MYC unaltered, and 7.8 months in those with MYC status unknown. The tolerable safety profile and encouraging evidence of durable anti-tumor activity, particularly in MYC-altered patients, support the continued development of CUDC-907 in these populations of high unmet need. (clinicaltrials.gov identifier: 01742988).

Chimeric antigen receptor T-cell therapies for lymphoma

New therapies are needed for patients with Hodgkin or non-Hodgkin lymphomas that are resistant to standard therapies. Indeed, unresponsiveness to standard chemotherapy and relapse after autologous stem-cell transplantation are indicators of an especially poor prognosis. Chimeric antigen receptor (CAR) T cells are emerging as a novel treatment modality for these patients. Clinical trial data have demonstrated the potent activity of anti-CD19 CAR T cells against multiple subtypes of B-cell lymphoma, including diffuse large-B-cell lymphoma (DLBCL), follicular lymphoma, mantle-cell lymphoma, and marginal-zone lymphoma. Importantly, anti-CD19 CAR T cells have impressive activity against chemotherapy-refractory lymphoma, inducing durable complete remissions lasting >2 years in some patients with refractory DLBCL. CAR-T-cell therapies are, however, associated with potentially fatal toxicities, including cytokine-release syndrome and neurological toxicities. CAR T cells with novel target antigens, including CD20, CD22, and κ-light chain for B-cell lymphomas, and CD30 for Hodgkin and T-cell lymphomas, are currently being investigated in clinical trials. Centrally manufactured CAR T cells are also being tested in industry-sponsored multicentre clinical trials, and will probably soon become a standard therapy. Herein, we review the clinical efficacy and toxicity of CAR-T-cell therapies for lymphoma, and discuss their limitations and future directions with regard to toxicity management, CAR designs and CAR-T-cell phenotypes, conditioning regimens, and combination therapies.

Long-Duration Complete Remissions of Diffuse Large B Cell Lymphoma after Anti-CD19 Chimeric Antigen Receptor T Cell Therapy

T cells expressing anti-CD19 chimeric antigen receptors (CARs) can induce complete remissions (CRs) of diffuse large B cell lymphoma (DLBCL). The long-term durability of these remissions is unknown. We administered anti-CD19 CAR T cells preceded by cyclophosphamide and fludarabine conditioning chemotherapy to patients with relapsed DLBCL. Five of the seven evaluable patients obtained CRs. Four of the five CRs had long-term durability with durations of remission of 56, 51, 44, and 38 months; to date, none of these four cases of lymphomas have relapsed. Importantly, CRs continued after recovery of non-malignant polyclonal B cells in three of four patients with long-term complete remissions. In these three patients, recovery of CD19⁺ polyclonal B cells took place 28, 38, and 28 months prior to the last follow-up, and each of these three patients remained in CR at the last follow-up. Non-malignant CD19⁺ B cell recovery with continuing CRs demonstrated that remissions of DLBCL can continue after the disappearance of functionally effective anti-CD19 CAR T cell populations. Patients had a low incidence of severe infections despite long periods of B cell depletion and hypogammaglobulinemia. Only one hospitalization for an infection occurred among the four patients with long-term CRs. Anti-CD19 CAR T cells caused long-term remissions of chemotherapy-refractory DLBCL without substantial chronic toxicities.

Lymphoma Remissions Caused by Anti-CD19 Chimeric Antigen Receptor T Cells Are Associated With High Serum Interleukin-15 Levels

Purpose T cells genetically modified to express chimeric antigen receptors (CARs) targeting CD19 (CAR-19) have potent activity against acute lymphoblastic leukemia, but fewer results supporting treatment of lymphoma with CAR-19 T cells have been published. Patients with lymphoma that is chemotherapy refractory or relapsed after autologous stem-cell transplantation have a grim prognosis, and new treatments for these patients are clearly needed. Chemotherapy administered before adoptive T-cell transfer has been shown to enhance the antimalignancy activity of adoptively transferred T cells. Patients and Methods We treated 22 patients with advanced-stage lymphoma in a clinical trial of CAR-19 T cells preceded by low-dose chemotherapy. Nineteen patients had diffuse large B-cell lymphoma, two patients had follicular lymphoma, and one patient had mantle cell lymphoma. Patients received a single dose of CAR-19 T cells 2 days after a low-dose chemotherapy conditioning regimen of cyclophosphamide plus fludarabine. Results The overall remission rate was 73% with 55% complete remissions and 18% partial remissions. Eleven of 12 complete remissions are ongoing. Fifty-five percent of patients had grade 3 or 4 neurologic toxicities that completely resolved. The low-dose chemotherapy conditioning regimen depleted blood lymphocytes and increased serum interleukin-15 (IL-15). Patients who achieved a remission had a median peak blood CAR⁺ cell level of 98/μL and those who did not achieve a remission had a median peak blood CAR⁺ cell level of 15/μL ( P = .027). High serum IL-15 levels were associated with high peak blood CAR⁺ cell levels ( P = .001) and remissions of lymphoma ( P < .001). Conclusion CAR-19 T cells preceded by low-dose chemotherapy induced remission of advanced-stage lymphoma, and high serum IL-15 levels were associated with the effectiveness of this treatment regimen. CAR-19 T cells will likely become an important treatment for patients with relapsed lymphoma.

Outcomes of primary refractory diffuse large B-cell lymphoma (DLBCL) treated with salvage chemotherapy and intention to transplant in the rituximab era

Rituximab-containing salvage chemotherapy followed by high-dose therapy and autologous stem cell transplant (ASCT) in chemosensitive patients remains the standard of care for patients with relapsed and refractory diffuse large B-cell lymphoma (DLBCL). However, its role in those patients achieving less than a complete response to first-line therapy (primary refractory disease) in the rituximab era is not well defined. We reviewed the outcomes of 82 transplant-eligible patients with primary refractory DLBCL who underwent salvage therapy with the intent of administering high-dose therapy and ASCT to patients achieving chemosensitive remission. The estimated 3-year overall and progression-free survival for all patients was 38% and 29%, respectively, and 65% and 60% respectively for patients proceeding to stem cell transplant. Long-term remission was achieved in 45% of patients achieving a partial response (PR) to initial induction therapy and <20% of patients with stable or progression of disease following initial therapy. These results suggest that salvage chemotherapy with the intent of subsequent high-dose therapy and ASCT remains a feasible strategy in certain patients with primary refractory DLBCL, particularly for those achieving a PR to frontline therapy. The primary barrier to curative therapy in patients with primary refractory disease is resistance to salvage therapy, and future studies should be aimed towards increasing the response rate in this population.

Lenalidomide for the treatment of B-cell lymphoma

INTRODUCTION

Although the combination of an anti-CD20 monoclonal antibody and chemotherapy has widely improved survival of patients with B-cell lymphoma, the disease still relapses. A better understanding of the biology of lymphomas has highlighted the role of the cell of origin in response to treatment and outcome. Lenalidomide represents an attractive therapeutic option due to its original mechanism of action.

AREAS COVERED

In this review, the authors describe the pharmacological properties of lenalidomide, and the rational for its use in B-cell lymphomas; focusing on diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and mantle cell lymphoma (MCL). They discuss the mechanism of action of the drug and its current and future clinical development. They also review the current data in relapsed/refractory situations as well as in first-line treatment.

EXPERT OPINION

Lenalidomide is an oral non-chemotherapy immunomodulatory agent with an acceptable toxicity profile and manageable side-effects. Efficacy has widely been demonstrated, especially in MCL, FL and non-Germinal Center DLBCL patients. Further studies are now warranted to better define the strategy for the use of lenalidomide in B-NHL patients, and clarify which subgroup of patients will really benefit of lenalidomide as part of first-line treatment or in a relapsed/refractory setting.

Combinatorial epigenetic therapy in diffuse large B cell lymphoma pre-clinical models and patients

BACKGROUND

Refractory and/or relapsed diffuse large B cell lymphoma (RR-DLBCL) patients are incurable with conventional chemotherapy due to the aggressiveness and the chemorefractory state of these tumors. DNA hypermethylation and histone deacetylation are two major epigenetic modifications by which aggressive DLBCL maintain their oncogenic state. We have previously reported that DNA methyltransferase inhibitors (DNMTI) affect RR-DLBCL growth and improve chemosensitivity. Here, we hypothesized that the combination of DNMTI with histone deacetylase inhibitor (HDI) would be an active and feasible therapeutic strategy in RR-DLBCL. Thus, we evaluated the anti-lymphoma activity of the HDI vorinostat (VST) in combination with the DNMTI azacitidine (AZA) or decitabine (DAC) in pre-clinical models of RR-DLBCL, and we determined the feasibility of the combination by conducting a phase Ib trial in RR-DLBCL patients.

RESULTS

Concurrent combination of DNMTI and HDI resulted in synergistic anti-lymphoma effect toward RR-DLBCL cells in vitro and in vivo, with no significant toxicity increase. In a phase Ib trial, a total of 18 patients with a median of three prior therapies were treated with four different dose levels of AZA and VST. The most common toxicities were hematological, followed by gastrointestinal and metabolic. The clinical benefit was low as only one subject had a partial response and three subjects had stable disease. Interestingly, two of the seven patients that received additional chemotherapy post-study achieved a complete response and three others had a significant clinical benefit. These observations suggested that the combination might have a delayed chemosensitization effect that we were able to confirm by using in vitro and in vivo models. These studies also demonstrated that the addition of VST does not improve the chemosensitizing effect of DAC alone.

CONCLUSIONS

Our data supports the strategy of epigenetic priming by employing DNMTI in RR-DLBCL patients in order to overcome resistance and improve their outcomes.

Safety, tolerability, and preliminary activity of CUDC-907, a first-in-class, oral, dual inhibitor of HDAC and PI3K, in patients with relapsed or refractory lymphoma or multiple myeloma: an open-label, dose-escalation, phase 1 trial

BACKGROUND

Treatment options for patients with relapsed or refractory lymphoma and multiple myeloma are limited. CUDC-907 is an oral, first-in-class, small molecule that is designed to inhibit both histone deacetylase (HDAC) and PI3K enzymes, which are members of common oncogenic pathways in haematological malignancies. We aimed to assess overall safety and preliminary activity in this dose-escalation study of CUDC-907 monotherapy in patients with relapsed or refractory lymphoma and multiple myeloma.

METHODS

This open-label, first-in-man, phase 1 trial recruited adult patients (aged ≥18 years) with lymphoma or multiple myeloma who were refractory to or had relapsed after two or more previous regimens, from four US cancer centres. CUDC-907 was orally administered in a standard 3 + 3 dose-escalation design at four different dosing schedules, to which participants were sequentially assigned as follows: once daily, intermittently (twice or three times weekly; simultaneous enrolment), and daily for 5 days followed by a 2-day break (5/2), in 21-day cycles. Dosing started at 30 mg for the once-daily schedule and 60 mg for other schedules, escalating in 30 mg increments. Patients continued to receive CUDC-907 until disease progression or until other treatment discontinuation criteria were met. The primary objective was to determine the maximum tolerated dose (MTD) and recommended phase 2 dose, assessed in patients who received at least 66% of cycle 1 doses without modification and those who had a dose-limiting toxicity (DLT) in cycle 1 irrespective of dose modification. We assessed safety in all patients who received at least one dose of study drug. This ongoing trial is registered at ClinicalTrials.gov, number NCT01742988.

FINDINGS

Between Jan 23, 2013, and July 27, 2015, we enrolled 44 patients, of whom ten were sequentially assigned to CUDC-907 once-daily (MTD 60 mg), 12 to twice-weekly (MTD 150 mg), 15 to three-times-weekly (MTD 150 mg), and seven to the 5/2 dosing schedule (MTD 60 mg). 37 (84%) patients had discontinued study drug as a result of progressive disease or clinical signs of progressive disease at the data cutoff. Four DLTs occurred in three of 40 DLT-evaluable patients (diarrhoea and hyperglycaemia in one patient on 60 mg once daily, hyperglycaemia in one patient on 150 mg twice weekly, and diarrhoea in one patient on 150 mg three times weekly); no DLTs were reported in patients on the 5/2 schedule. Grade 3 or worse adverse events occurred in 19 (43%) of 44 patients, the most common of which were thrombocytopenia (in nine [20%] of 44 patients), neutropenia (three [7%]), and hyperglycaemia (three [7%]). 11 (25%) of 44 patients had serious adverse events, three of which were regarded as treatment related (epistaxis and the DLTs of diarrhoea and hyperglycaemia). Adverse events led to dose reductions in six (14%) patients and treatment discontinuation in seven (16%). Five (14%) of 37 response-evaluable patients achieved an objective response (two complete responses and three partial responses). All five responses occurred in the subgroup of patients with diffuse large B-cell lymphoma (DLBCL; n=9), and three occurred in those with transformed follicular lymphoma DLBCL (n=5). 21 (57%) of 37 response-evaluable patients had stable disease, including those with DLBCL, Hodgkin's lymphoma, and multiple myeloma. On the basis of these findings, we selected CUDC-907 60 mg on the 5/2 dosing schedule as the recommended phase 2 dose.

INTERPRETATION

The safety and tolerability profile of CUDC-907 and the promising preliminary evidence of response support continued development of CUDC-907 at the 60 mg 5/2 dosing schedule, alone and in combination with other therapies. A dose-expansion trial of this dose in patients with refractory and relapsed DLBCL in particular, is ongoing.

FUNDING

Curis, Inc, and the Leukemia and Lymphoma Society.

Outcome of patients with relapsed diffuse large B-cell lymphoma who fail second-line salvage regimens in the International CORAL study

Salvage chemotherapy followed by autologous stem cell transplantation (ASCT) is the standard second-line treatment for relapsed and refractory diffuse large B-cell lymphoma (DLBCL). However, the strategy is less clear in patients who require third-line treatment. Updated outcomes of 203 patients who could not proceed to scheduled ASCT in the Collaborative Trial in Relapsed Aggressive Lymphoma (CORAL) are herein reviewed. In the intent-to-treat analysis, overall response rate to third-line chemotherapy was 39%, with 27% CR or CR unconfirmed, and 12% PR. Among the 203 patients, 64 (31.5%) were eventually transplanted (ASCT 56, allogeneic SCT 8). Median overall survival (OS) of the entire population was 4.4 months. OS was significantly improved in patients with lower tertiary International Prognostic Index (IPI), patients responding to third-line treatment and patients transplanted with a 1-year OS of 41.6% compared with 16.3% for the not transplanted (P<0.0001). In multivariate analysis, IPI at relapse (hazard ratio (HR) 2.409) and transplantation (HR 0.375) independently predicted OS. Third-line salvage chemotherapy can lead to response followed by transplantation and long-term survival in DLBCL patients. However, improvement of salvage efficacy is an urgent need with new drugs.

Approach to therapy of diffuse large B-cell lymphoma in the elderly: the International Society of Geriatric Oncology (SIOG) expert position commentary

Diffuse large B-cell lymphoma (DLBCL) is a treatable and potentially curable malignancy that is increasing in prevalence in the elderly. Until recently, older patients with this malignancy were under-represented on clinical treatment trials, so optimal therapeutic approaches for these patients were generally extrapolated from the treatment of younger patients with this disorder. Because of heightened toxicity concerns, older patients were sometimes given reduced dose therapy, potentially negatively impacting outcome. Geriatric considerations including functional status and comorbidities often were not accounted for in treatment decisions. Because of these issues as well as the lack of treatment guidelines for the elderly population, the International Society of Geriatric Oncology convened an expert panel to review DLBCL treatment in the elderly and develop consensus guidelines for therapeutic approaches in this patient population. The following treatment guidelines address initial DLBCL therapy, in both limited and advanced stage disease, as well as approaches to the relapsed and refractory patient.

Constitutive NF- κ B Activation Underlines Major Mechanism of Drug Resistance in Relapsed Refractory Diffuse Large B Cell Lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common subtype of B cell non-Hodgkin's lymphoma (NHL), encompassing 30-40% of the estimated 70,000 cases of NHL in 2014 in the USA. Despite major improvements with immune-chemotherapy, the fraction of patients who still succumb to a refractory or relapsed disease remains high. This review addresses whether the better understanding of the biology of DLBCL defines new therapeutic avenues that may overcome the emerging resistance of this disease to traditional immune-chemotherapy, such as rituximab in combination with traditional chemotherapy agents. Emerging targeted therapy for relapsed refractory DLBCL encompasses more complex molecular abnormalities involving signaling pathways other than NF-κB as mechanism of resistance to immune-chemotherapy. Our review suggests that NF-κB pathway is an important crossroad where other pathways converge as phenotype of resistance that emerges in patients who fail frontline and salvage immune-chemotherapy. Future efforts should aim at targeting the role of NF-κB resistance in clinical trials, where novel agents like lenalidomide and proteasome inhibitors with established activity in this perspective will be an important component in combination therapy, along with new monoclonal antibody, BTK-inhibitors, and other novel therapy agents.

Brentuximab vedotin demonstrates objective responses in a phase 2 study of relapsed/refractory DLBCL with variable CD30 expression

Brentuximab vedotin was active in DLBCL across a range of CD30 expression levels, and objective responses occurred in 44% of patients.

Chemotherapy-refractory diffuse large B-cell lymphoma and indolent B-cell malignancies can be effectively treated with autologous T cells expressing an anti-CD19 chimeric antigen receptor

PURPOSE

T cells can be genetically modified to express an anti-CD19 chimeric antigen receptor (CAR). We assessed the safety and efficacy of administering autologous anti-CD19 CAR T cells to patients with advanced CD19(+) B-cell malignancies.

PATIENTS AND METHODS

We treated 15 patients with advanced B-cell malignancies. Nine patients had diffuse large B-cell lymphoma (DLBCL), two had indolent lymphomas, and four had chronic lymphocytic leukemia. Patients received a conditioning chemotherapy regimen of cyclophosphamide and fludarabine followed by a single infusion of anti-CD19 CAR T cells.

RESULTS

Of 15 patients, eight achieved complete remissions (CRs), four achieved partial remissions, one had stable lymphoma, and two were not evaluable for response. CRs were obtained by four of seven evaluable patients with chemotherapy-refractory DLBCL; three of these four CRs are ongoing, with durations ranging from 9 to 22 months. Acute toxicities including fever, hypotension, delirium, and other neurologic toxicities occurred in some patients after infusion of anti-CD19 CAR T cells; these toxicities resolved within 3 weeks after cell infusion. One patient died suddenly as a result of an unknown cause 16 days after cell infusion. CAR T cells were detected in the blood of patients at peak levels, ranging from nine to 777 CAR-positive T cells/μL.

CONCLUSION

This is the first report to our knowledge of successful treatment of DLBCL with anti-CD19 CAR T cells. These results demonstrate the feasibility and effectiveness of treating chemotherapy-refractory B-cell malignancies with anti-CD19 CAR T cells. The numerous remissions obtained provide strong support for further development of this approach.

Paclitaxel, topotecan and rituximab: long term outcomes of an effective salvage programme for relapsed or refractory aggressive B-cell non-Hodgkin lymphoma

Relapsed aggressive lymphomas are often treated with platinum-based chemotherapy (PBC) followed by an autologous stem cell transplant (ASCT). Response rates to PBC in patients with relapsed aggressive lymphomas are c. 60%, and non-responders have a dismal prognosis. Novel therapies for aggressive lymphomas, including those failing PBC, are needed. We performed a phase II study of paclitaxel, topotecan and rituximab (TTR) in patients with relapsed or refractory diffuse large B-cell, follicular grade IIIB, or transformed lymphomas, including those who previously failed PBC. The median age of the 72 patients enrolled was 54 years. Responding patients were offered ASCT after two courses. The overall response rate was 69% for all patients (n = 49/71) and 45% for those who previously failed PBC (n = 9/20). With a median follow up of 125 months for the censored observations, the overall survival (OS) and progression-free survival at 5 years was 39% and 27%, respectively. Responding patients who received ASCT had an OS of 63% at 5 years. Our results demonstrate that TTR is an effective salvage regimen for patients with relapsed aggressive B-cell lymphomas, including those who previously failed PBC. Given the declining therapeutic outcomes of salvage PBC in the rituximab era, further evaluation of TTR is warranted.

Allotransplantation for patients age ≥40 years with non-Hodgkin lymphoma: encouraging progression-free survival

Non-Hodgkin lymphoma (NHL) disproportionately affects older patients, who do not often undergo allogeneic hematopoietic cell transplantation (HCT). We analyzed Center for International Blood and Marrow Transplant Research data on 1248 patients age ≥40 years receiving reduced-intensity conditioning (RIC) or nonmyeloablative (NMA) conditioning HCT for aggressive (n = 668) or indolent (n = 580) NHL. Aggressive lymphoma was more frequent in the oldest cohort 49% for age 40 to 54 versus 57% for age 55 to 64 versus 67% for age ≥65; P = .0008). Fewer patients aged ≥65 had previous autografting (26% versus 24% versus 9%; P = .002). Rates of relapse, acute and chronic GVHD, and nonrelapse mortality (NRM) at 1 year post-HCT were similar in the 3 age cohorts (22% [95% confidence interval (CI), 19% to 26%] for age 40 to 54, 27% [95% CI, 23% to 31%] for age 55 to 64, and 34% [95% CI, 24% to 44%] for age ≥65. Progression-free survival (PFS) and overall survival (OS) at 3 years was slightly lower in the older cohorts (OS: 54% [95% CI, 50% to 58%] for age 40 to 54; 40% [95% CI, 36% to 44%] for age 55 to 64, and 39% [95% CI, 28% to 50%] for age ≥65; P < .0001). Multivariate analysis revealed no significant effect of age on the incidence of acute or chronic GVHD or relapse. Age ≥55 years, Karnofsky Performance Status <80, and HLA mismatch adversely affected NRM, PFS, and OS. Disease status at HCT, but not histological subtype, was associated with worse NRM, relapse, PFS, and OS. Even for patients age ≥55 years, OS still approached 40% at 3 years, suggesting that HCT affects long-term remission and remains underused in qualified older patients with NHL.

Mechanism-based epigenetic chemosensitization therapy of diffuse large B-cell lymphoma

Although aberrant DNA methylation patterning is a hallmark of cancer, the relevance of targeting DNA methyltransferases (DNMT) remains unclear for most tumors. In diffuse large B-cell lymphoma (DLBCL) we observed that chemoresistance is associated with aberrant DNA methylation programming. Prolonged exposure to low-dose DNMT inhibitors (DNMTI) reprogrammed chemoresistant cells to become doxorubicin sensitive without major toxicity in vivo. Nine genes were recurrently hypermethylated in chemoresistant DLBCL. Of these, SMAD1 was a critical contributor, and reactivation was required for chemosensitization. A phase I clinical study was conducted evaluating azacitidine priming followed by standard chemoimmunotherapy in high-risk patients newly diagnosed with DLBCL. The combination was well tolerated and yielded a high rate of complete remission. Pre- and post-azacitidine treatment biopsies confirmed SMAD1 demethylation and chemosensitization, delineating a personalized strategy for the clinical use of DNMTIs.

SIGNIFICANCE

The problem of chemoresistant DLBCL remains the most urgent challenge in the clinical management of patients with this disease. We describe a mechanism-based approach toward the rational translation of DNMTIs for the treatment of high-risk DLBCL.

Relapsed/refractory diffuse large B-cell lymphoma

Despite overall improvements in outcomes of diffuse large B-cell lymphoma (DLBCL), approximately one-third of patients will develop relapsed/refractory disease that remains a major cause of morbidity and mortality. Novel insights from gene-expression analyses have increased our understanding of chemotherapy resistance and yielded rational targets for therapeutic intervention to both prevent and treat relapsed/refractory DLBCL. The clinical approach to relapsed/refractory DLBCL should include high-dose therapy and autologous stem cell transplantation (HD-ASCT) with curative intent in patients without comorbidities. Results from the recently reported CORAL study suggest that patients refractory to rituximab-containing regimens have inferior outcomes with HD-ASCT. Ongoing efforts to improve ASCT include novel conditioning regimens and evaluation of maintenance approaches after ASCT. Unfortunately, because the majority of patients are not eligible for ASCT due to refractory disease or age/comorbidities, these approaches have limited impact. The large group of patients not eligible for ASCT have incurable disease and should be referred for clinical trials of rationally targeted agents.