Higher response to lenalidomide in relapsed/refractory diffuse large B-cell lymphoma in nongerminal center B-cell-like than in germinal center B-cell-like phenotype

EBV-positive diffuse large B-cell lymphoma, not otherwise specified: 2024 update on the diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Epstein Barr virus-positive (EBV+) diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS) is an aggressive B-cell lymphoma associated with EBV infection included in the WHO classification of lymphoid neoplasms since 2016. Although historically associated to poor prognosis, outcomes seem to have improved in the era of chemoimmunotherapy.

DIAGNOSIS

The diagnosis is established through meticulous pathological evaluation. Detection of EBV-encoded RNA (EBER) is the standard diagnostic method. The ICC 2022 specifies EBV+ DLBCL, NOS as occurring when >80% of malignant cells express EBER, whereas the WHO-HAEM5 emphasizes that the majority of tumor cells should be EBER positive without setting a defined threshold. The differential diagnosis includes plasmablastic lymphoma, DLBCL associated with chronic inflammation, primary effusion lymphoma, among others.

RISK-STRATIFICATION

The International Prognostic Index (IPI) and the Oyama score can be used for risk-stratification. The Oyama score includes age >70 years and presence of B symptoms. The expression of CD30 and PD-1/PD-L1 are emerging as potential adverse but targetable biomarkers.

MANAGEMENT

Patients with EBV+ DLBCL, NOS, should be staged and managed following similar guidelines than patients with EBV-negative DLBCL. EBV+ DLBCL, NOS, however, might have a worse prognosis than EBV-negative DLBCL in the era of chemoimmunotherapy. Therefore, inclusion of patients in clinical trials when available is recommended. There is an opportunity to study and develop targeted therapy in the management of patients with EBV+ DLBCL, NOS.

Combination Targeted Therapy in Relapsed Diffuse Large B-Cell Lymphoma

BACKGROUND

The identification of oncogenic mutations in diffuse large B-cell lymphoma (DLBCL) has led to the development of drugs that target essential survival pathways, but whether targeting multiple survival pathways may be curative in DLBCL is unknown.

METHODS

We performed a single-center, phase 1b-2 study of a regimen of venetoclax, ibrutinib, prednisone, obinutuzumab, and lenalidomide (ViPOR) in relapsed or refractory DLBCL. In phase 1b, which included patients with DLBCL and indolent lymphomas, four dose levels of venetoclax were evaluated to identify the recommended phase 2 dose, with fixed doses of the other four drugs. A phase 2 expansion in patients with germinal-center B-cell (GCB) and non-GCB DLBCL was performed. ViPOR was administered every 21 days for six cycles.

RESULTS

In phase 1b of the study, involving 20 patients (10 with DLBCL), a single dose-limiting toxic effect of grade 3 intracranial hemorrhage occurred, a result that established venetoclax at a dose of 800 mg as the recommended phase 2 dose. Phase 2 included 40 patients with DLBCL. Toxic effects that were observed among all the patients included grade 3 or 4 neutropenia (in 24% of the cycles), thrombocytopenia (in 23%), anemia (in 7%), and febrile neutropenia (in 1%). Objective responses occurred in 54% of 48 evaluable patients with DLBCL, and complete responses occurred in 38%; complete responses were exclusively in patients with non-GCB DLBCL and high-grade B-cell lymphoma with rearrangements of MYC and BCL2 or BCL6 (or both). Circulating tumor DNA was undetectable in 33% of the patients at the end of ViPOR therapy. With a median follow-up of 40 months, 2-year progression-free survival and overall survival were 34% (95% confidence interval [CI], 21 to 47) and 36% (95% CI, 23 to 49), respectively.

CONCLUSIONS

Treatment with ViPOR was associated with durable remissions in patients with specific molecular DLBCL subtypes and was associated with mainly reversible adverse events. (Funded by the Intramural Research Program of the National Cancer Institute and the National Center for Advancing Translational Sciences of the National Institutes of Health and others; ClinicalTrials.gov number, NCT03223610.).

New Insights into First-Line Therapy in Diffuse Large B-Cell Lymphoma: Are We Improving Outcomes?

Diffuse large B-cell lymphoma (DLBCL) is the most prevalent subtype of lymphoma, comprising heterogeneous patient subgroups with distinctive biological and clinical characteristics. The R-CHOP combination (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) has been the standard initial treatment, yielding prolonged remissions in over 60% of patients with advanced-stage disease. Several attempts to enhance the outcomes of this regimen over the last two decades have shown limited success. Various novel therapeutic approaches have recently emerged in lymphoma, demonstrating promising results. These include small molecules, novel monoclonal antibodies, antibody-drug conjugates (ADC), bispecific antibodies (BsAbs), and chimeric antigen receptor (CAR) T-cell therapy. This review explores recent advancements in therapeutic strategies for DLBCL and their potential impact on the initial management of DLBCL patients.

A phase II study of lenalidomide and rituximab (R2) combination in patients with high-risk refractory/relapsed diffuse large B-cell lymphoma

Relapsed/Refractory Diffuse Large B Cell Lymphoma have a dismal prognosis in need of innovative treatments. This prospective phase 2 study enrolled 32 patients between 2013 and 2017 with Relapsed/Refractory Diffuse Large B Cell Lymphoma treated with Rituximab and Lenalidomide (R2). Median age was 69 years (40-86), 90.1% had received at least 2 prior lines of treatment, 81% were defined as having High Risk disease according to our criteria and ECOG performance status was > 2 in 51.6%. Patients received a median number of 2 cycles of R2 (1-12). With a median follow up of 22.6 months, the objective response rate was 12.5%. Median progression free survival was 2.6 months (95% CI, [1.7-2.9]) and median overall survival was 9.3 months (95% CI, [5.1-Not estimable]). This study therefore did not achieve its primary endpoint and the R2 regimen cannot be recommended in Relapsed/Refractory Diffuse Large B Cell Lymphoma patients with High Risk features.

Lenalidomide plus rituximab for the initial treatment of frail older patients with DLBCL: the FIL_ReRi phase 2 study

Treatment of diffuse large B-cell lymphoma (DLBCL) in older patients is challenging, especially for those who are not eligible for anthracycline-containing regimens. Fondazione Italiana Linfomi (FIL) started the FIL_ReRi study, a 2-stage single-arm trial to investigate the activity and safety of the chemo-free combination of rituximab and lenalidomide (R2) in ≥70-year-old untreated frail patients with DLBCL. Frailty was prospectively defined using a simplified geriatric assessment tool. Patients were administered a maximum of 6 28-day cycles of 20 mg oral lenalidomide from days 2 to 22 and IV rituximab 375 mg/m2 on day 1, with response assessment after cycles 4 and 6. Patients with partial response or complete response (CR) at cycle 6 were administered lenalidomide 10 mg/d from days 1 to 21 for every 28 cycles for a total of 12 cycles or until progression or unacceptable toxicity. The primary end point was the overall response rate (ORR) after cycle 6; the coprimary end point was the rate of grade 3 or 4 extrahematological toxicity. The ORR was 50.8%, with 27.7% CR. After a median follow-up of 24 months, the median progression-free survival was 14 months, and the 2-year duration of response was 64%. Thirty-four patients experienced extrahematological toxicity according to the National Cancer Institute Common Terminology Criteria for Adverse Events grade ≥3. The activity of the R2 combination was observed in a significant proportion of subjects, warranting further exploration of a chemo-free approach in frail older patients with DLBCL. This trial was registered at EudraCT as #2015-003371-29 and clinicaltrials.gov as #NCT02955823.

Lenalidomide in combination with R-ESHAP in patients with relapsed or refractory diffuse large B-cell lymphoma: A phase 2 study from GELTAMO

Diffuse large B-cell lymphoma (DLBCL) patients with relapsed or refractory (RR) disease have poor outcomes with current salvage regimens. We conducted a phase 2 trial to analyse the safety and efficacy of adding lenalidomide to R-ESHAP (LR-ESHAP) in patients with RR DLBCL. Subjects received 3 cycles of lenalidomide 10 mg/day on days 1-14 of every 21-day cycle, in combination with R-ESHAP at standard doses. Responding patients underwent autologous stem-cell transplantation (ASCT). The primary endpoint was the overall response rate (ORR) after 3 cycles. Centralized cell-of-origin (COO) classification was performed. Forty-six patients were included. The ORR after LR-ESHAP was 67% (35% of patients achieved complete remission). Patients with primary refractory disease (n = 26) had significantly worse ORR than patients with non-refractory disease (54% vs. 85%, p = 0.031). No differences in response rates according to the COO were observed. Twenty-eight patients (61%) underwent ASCT. At a median follow-up of 41 months, the estimated 3-year PFS and OS were 42% and 48%, respectively. The most common grade ≥3 adverse events were thrombocytopenia (70% of patients), neutropenia (67%) and anaemia (35%). There were no treatment-related deaths during LR-ESHAP cycles. In conclusion, LR-ESHAP is a feasible salvage regimen with promising efficacy results for patients with RR DLBCL.

The progress of novel strategies on immune-based therapy in relapsed or refractory diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) can be cured with standard front-line immunochemotherapy, whereas nearly 30-40% of patients experience refractory or relapse. For several decades, the standard treatment strategy for fit relapsed/refractory (R/R) DLBCL patients has been high-dose chemotherapy followed by autologous hematopoietic stem cell transplant (auto-SCT). However, the patients who failed in salvage treatment or those ineligible for subsequent auto-SCT have dismal outcomes. Several immune-based therapies have been developed, including monoclonal antibodies, antibody-drug conjugates, bispecific T-cell engaging antibodies, chimeric antigen receptor T-cells, immune checkpoint inhibitors, and novel small molecules. Meanwhile, allogeneic SCT and radiotherapy are still necessary for disease control for fit patients with certain conditions. In this review, to expand clinical treatment options, we summarize the recent progress of immune-related therapies and prospect the future indirections in patients with R/R DLBCL.

Targeted Treatment of Adults with Relapsed or Refractory Diffuse Large B-Cell Lymphoma (DLBCL): Tafasitamab in Context

The outcomes of Relapsed/Refractory (R/R) Diffuse Large B-cell lymphoma have been historically poor. The recent development of several novel therapies including CD19 directed agents has improved the prognosis of this disease significantly. Chimeric antigen receptor (CAR) T-cell therapy has drastically changed the treatment of R/R DLBCL, but it is still associated with significant barriers and limited access. Tafasitamab (an anti-CD19 engineered monoclonal antibody), in addition to lenalidomide, has shown significant efficacy with exceptionally durable responses in patients with R/R DLBCL who are ineligible for autologous stem cell transplantation (ASCT). Tafasitamab-lenalidomide and certain other therapies (ie, antibody-drug conjugates and bispecific antibodies) are important treatment options for patients who are ineligible for CAR-T due to co-morbidities or lack of access, and patients with rapid progression of disease who are unable to wait for manufacturing of CAR-T. This review will thus discuss currently approved and recently studied targeted treatment options for patients with R/R DLBCL with an emphasis on CAR-T alternative options, particularly Tafasitamab-lenalidomide.

PD-1 blockade combined with ICE regimen in relapsed/refractory diffuse large B-cell lymphoma

The prognosis of relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) is poor. The efficacy of salvage therapy with ICE (ifosfamide, carboplatin, and etoposide) is limited. DLBCL can evade immune surveillance by upregulating programmed cell death ligand 1 (PD-L1). The purpose of this study was to explore the efficacy and safety of programmed cell death 1 (PD-1) blockade combined with ICE regimen (P-ICE) in the treatment of R/R DLBCL patients. In this study, we retrospectively explored efficacy and toxicity in R/R DLBCL patients treated with P-ICE. Prognostic biomarkers, including clinical features and molecular markers related to efficacy, were explored. From February 2019 to May 2020, a total of 67 patients treated with the P-ICE regimen were analyzed. The median follow-up time was 24.7 months (range: 1.4-39.6 months), with an objective response rate (ORR) of 62.7% and a complete response rate (CRR) of 43.3%. The 2-year progression-free survival (PFS) and overall survival (OS) rates were 41.1% (95% CI: 35.0-47.2%) and 65.6% (95% CI: 59.5-71.7%), respectively. Age, Ann Arbor stage, international prognostic index (IPI) score, and response to first-line chemotherapy were correlated with the ORR. Grade 3 and 4 adverse events (AEs) related to the P-ICE regimen were reported in 21.5% of patients. The most common AE was thrombocytopenia (9.0%). No treatment-related deaths occurred. In patients with R/R DLBCL, the P-ICE regimen has promising efficacy and mild toxicity.

Diagnosis and management of vitreoretinal lymphoma: present and future treatment perspectives

Intraocular lymphoma (IOL) is a rare malignant intraocular lymphocytic tumor that mimics uveitis. IOL is anatomically classified into vitreoretinal lymphoma (VRL) and uveal lymphoma; most IOLs are VRLs, while uveal lymphoma is rare. VRL is highly malignant, with 60%-85% of patients developing central nervous system (CNS) lymphoma; primary VRL (PVRL) is an ocular disease with poor prognosis. We aimed to review the management and both current and future treatments for VRL. VRL diagnosis is based on the results of cytopathological examination using vitreous biopsy. However, the positive ratio of vitreous cytology remains 29%-70%. A combination of adjunctive tests may improve diagnostic accuracy, but as yet no gold-standard regimen has been established. Methotrexate intravitreal injections are effective in controlling ocular lesions; however, this treatment allows CNS dissemination. The efficacy of systemic chemotherapy in suppressing CNS dissemination has been recently debated. A multicenter prospective study with a unified treatment protocol is required to clarify this issue. In addition, establishing a treatment protocol for elderly patients and those with poor general health is necessary. Moreover, relapsed/refractory VRL and secondary VRL are more difficult to treat than PVRL because they are prone to recurrence. Ibrutinib, lenalidomide with or without rituximab, and temozolomide are promising treatments for relapsed/refractory VRL. In Japan, Bruton's tyrosine kinase (BTK) inhibitors have been approved for treating refractory CNS lymphoma. Furthermore, a randomized prospective study of tirabrutinib, a highly selective BTK inhibitor, is ongoing for evaluating the suppressing of CNS progression in patients with PVRL.

Real-world data for lenalidomide maintenance in responding patients of diffuse large B-cell lymphoma

BACKGROUND

Approximately 40% patients of diffuse large B-cell lymphoma (DLBCL) would develop disease recurrence/progression after first-line R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) induction therapy, with highly poor prognosis. An effective strategy to prolong the survival of this patient population is the additional single-drug maintenance therapy. lenalidomide, an immunomodulatory drug with oral activity, has direct anti-tumor activity and indirect effects mediated by multiple immune cells in the tumor microenvironment, such as B, T, natural killer (NK), and dendritic cells. Combining its controllable toxicity, it is promising in long-term maintenance therapy. This study aims at evaluating the clinical effect of lenalidomide maintenance therapy in responding DLBCL patients with R-CHOP treatment.

METHODS

This retrospective study was devised in DLBCL cases who obtained complete response (CR) or partial response (PR) following 6-8 cycles of R-CHOP treatment between January 1, 2015 and July 31, 2019. Patients (n = 141) included were respectively assigned to receive lenalidomide maintenance treatment (lenalidomide, n = 50) and drug-free maintenance treatment (control, n = 91) after CR/PR. lenalidomide was provided orally at 25 mg/day for 10 days, with a cycle of 21 days and a treatment course of 2 years. Progression-free survival (PFS) was taken as the primary outcome.

RESULTS

Of the total 141 subjects, the median follow-up time was 30.9 months (range, 5.7-68.9 months). The 2-year PFS was 84% (95% CI: 74%-94%) in the lenalidomide group and 53% (95% CI: 43%-63%) in the control group. The median PFS of the lenalidomide group was not reached, and that of the control group was 42.9 months (HR = 0.32; 95% CI: 0.16-0.63; p = 0.001). No remarkable difference in overall survival (OS) between the two groups was indicated (HR = 0.42; 95% CI: 0.16-1.12; p = 0.08). Central nervous system (CNS) recurrence happened in 5 patients (5.5%) of the control group, while none of the patients with lenalidomide had CNS recurrence. Additionally, neutropenia and cutaneous reactions were the most common Grade 1-2 adverse reactions after lenalidomide treatment, and neutropenia was the most frequent Grade 3-4 adverse reaction.

CONCLUSION

Two-year lenalidomide maintenance treatment can significantly prolong the PFS of DLBCL patients who obtained CR/PR to first-line R-CHOP treatment.

Molecular classification and therapeutics in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) encompasses a wide variety of disease states that have to date been subgrouped and characterized based on immunohistochemical methods, which provide limited prognostic value to clinicians and no alteration in treatment regimen. The addition of rituximab to CHOP therapy was the last leap forward in terms of treatment, but regimens currently follow a standardized course when disease becomes refractory with no individualization based on genotype. Research groups are tentatively proposing new strategies for categorizing DLBCL based on genetic abnormalities that are frequently found together to better predict disease course following dysregulation of specific pathways and to deliver targeted treatment. Novel algorithms in combination with next-generation sequencing techniques have identified between 4 and 7 subgroups of DLBCL, depending on the research team, with potentially significant and actionable genetic alterations. Various drugs aimed at pathways including BCR signaling, NF-κB dysfunction, and epigenetic regulation have shown promise in their respective groups and may show initial utility as second or third line therapies to patients with recurrent DLBCL. Implementation of subgroups will allow collection of necessary data to determine which groups are significant, which treatments may be indicated, and will provide better insight to clinicians and patients on specific disease course.

The iR2 regimen (ibrutinib plus lenalidomide and rituximab) for relapsed/refractory DLBCL: A multicentre, non-randomised, open-label phase 2 study

BACKGROUND

This phase 1b/2 PCYC-1123-CA study evaluated efficacy and safety of the combination of ibrutinib, lenalidomide, and rituximab (iR² regimen) in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) ineligible for stem cell transplantation.

METHODS

In phase 2, patients with relapsed/refractory non-germinal centre B-cell-like DLBCL received oral ibrutinib 560 mg once daily and oral lenalidomide 20 mg or 25 mg once daily on Days 1-21 of each 28-day cycle until disease progression or unacceptable toxicity and intravenous rituximab 375 mg/m² on Day 1 of Cycles 1-6. The primary endpoint was overall response rate (ORR) in the response-evaluable population (received any study treatment and had ≥1 post-baseline disease assessment). The study was done at 24 academic and community hospitals in Belgium, Germany, United Kingdom, and USA. This study was registered with ClinicalTrials.gov, NCT02077166.

FINDINGS

Between March 13, 2014 and October 2, 2018, 89 patients were enrolled with a median time on study of 35.0 months. Best ORR in the response-evaluable population (n = 85) was 49% (95% confidence interval [CI], 38-61) across dose cohorts and 53% (95% CI, 39-67) and 44% (95% CI, 26-62) in the 20 mg and 25 mg lenalidomide cohorts, respectively, with complete responses in 24/85 (28%), 17/53 (32%), and 7/32 (22%) patients, respectively. Grade 3/4 adverse events (AEs) occurred in 81/89 patients (91%), most frequently neutropenia (36/89; 40%), maculopapular rash (16/89; 18%), anaemia (12/89; 13%), and diarrhoea (9/89; 10%). Serious adverse events occurred in 57/89 patients (64%). Fatal AEs occurred in 12/89 patients (13%); causes of death were worsening of DLBCL (n = 7), pneumonia (n = 3), sepsis (n = 1), and cardiac arrest (n = 1).

INTERPRETATION

The most frequent AEs (diarrhoea, neutropenia, fatigue, cough, anaemia, peripheral oedema, and maculopapular rash) were consistent with known safety profiles of the individual drugs. The iR² regimen demonstrated antitumour activity with durable responses in patients with relapsed/refractory DLBCL.

FUNDING

Pharmacyclics LLC, an AbbVie Company.

Smart Start: Rituximab, Lenalidomide, and Ibrutinib in Patients With Newly Diagnosed Large B-Cell Lymphoma

PURPOSE

Chemoimmunotherapy for patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) is largely unchanged for decades. Both preclinical models and clinical data suggest the combination of lenalidomide and ibrutinib may have synergy in DLBCL, particularly in the non-germinal center B-cell-like subset.

METHODS

We enrolled 60 patients with newly diagnosed non-germinal center B-cell-like DLBCL in this investigator-initiated, single-arm phase II trial of rituximab, lenalidomide, and ibrutinib (RLI) with the sequential addition of chemotherapy (ClinicalTrials.gov identifier: NCT02636322). Patients were treated with rituximab 375 mg/m2 intravenous once on day 1, lenalidomide 25 mg once per day on days 1-10, and ibrutinib 560 mg once daily continuously of each 21-day cycle (RLI). After two cycles, standard chemotherapy was added to RLI for six additional cycles. The primary end points were overall response rate (ORR) after two cycles of RLI alone and complete response rate after completion of RLI with chemotherapy. In evaluable samples, circulating tumor DNA and DLBCL90 assays were performed.

RESULTS

The median age was 63.5 years (range, 29-83 years) with 28% age 70 years or older. The revised international prognostic index identified 42% as high risk, and 62% were double expressor of MYC and BCL2 protein. The ORR after two cycles of RLI was 86.2%, and the complete response rate at the end of RLI-chemotherapy was 94.5%. With a median follow-up of 31 months, the progression-free survival and overall survival were at 91.3% and 96.6% at 2 years, respectively.

CONCLUSION

Smart Start is the first study, to our knowledge, to treat newly diagnosed DLBCL with a targeted therapy combination before chemotherapy. RLI produced a high ORR, and RLI with chemotherapy resulted in durable responses. This establishes the potential for developing biologically driven and noncytotoxic first-line therapies for DLBCL.

Targeting CD19 for diffuse large B cell lymphoma in the era of CARs: Other modes of transportation

CD19 is nearly ubiquitously expressed on B-lymphocytes and in B-cell malignancies. Although CD19-directed CAR T cells have greatly improved outcomes in B-cell malignancies, there are significant limitations with this therapy. CD19 can also be effectively targeted by other drug classes, such as monoclonal antibodies, antibody-drug conjugates, and bispecific T cell engagers or antibodies. However, the optimal patient selection and sequencing of these novel therapies has not yet been established. In this review, we discuss the utilization of CD19 as a target for the treatment of DLBCL, focusing on tafasitamab, loncastuximab tesirine, and blinatumomab. We provide a comprehensive review of the pivotal clinical trials, discussing the strength and limitations of the data for each agent. We explore the emerging evidence that CD19 expression is retained following exposure to these agents and that patients can be successfully re-challenged with anti-CD19 therapies of a different drug class upon disease relapse post-CAR T cells. Finally, we discuss how these drugs potentially fit into the most current treatment paradigm for DLBCL.

Investigation of the anti-tumor mechanism of tirabrutinib, a highly selective Bruton's tyrosine kinase inhibitor, by phosphoproteomics and transcriptomics

Tirabrutinib is a highly selective Bruton's tyrosine kinase (BTK) inhibitor used to treat hematological malignancies. We analyzed the anti-tumor mechanism of tirabrutinib using phosphoproteomic and transcriptomic methods. It is important to check the drug's selectivity against off-target proteins to understand the anti-tumor mechanism based on the on-target drug effect. Tirabrutinib's selectivity was evaluated by biochemical kinase profiling assays, peripheral blood mononuclear cell stimulation assays, and the BioMAP system. Next, in vitro and in vivo analyses of the anti-tumor mechanisms were conducted in activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL) cells followed by phosphoproteomic and transcriptomic analyses. In vitro kinase assays showed that, compared with ibrutinib, tirabrutinib and other second-generation BTK inhibitors demonstrated a highly selective kinase profile. Data from in vitro cellular systems showed that tirabrutinib selectively affected B-cells. Tirabrutinib inhibited the cell growth of both TMD8 and U-2932 cells in correlation with the inhibition of BTK autophosphorylation. Phosphoproteomic analysis revealed the downregulation of ERK and AKT pathways in TMD8. In the TMD8 subcutaneous xenograft model, tirabrutinib showed a dose-dependent anti-tumor effect. Transcriptomic analysis indicated that IRF4 gene expression signatures had decreased in the tirabrutinib groups. In conclusion, tirabrutinib exerted an anti-tumor effect by regulating multiple BTK downstream signaling proteins, such as NF-κB, AKT, and ERK, in ABC-DLBCL.

Primary extranodal diffuse large B-cell lymphoma in the rituximab era: a single center, retrospective analysis

OBJECTIVES

To analyse the clinical characteristics and therapeutic response of Chinese patients with primary extranodal diffuse large B-cell lymphoma DLBCL (PE-DLBCL).

METHODS

We analysed the clinical features and outcomes of 197 patients who were newly diagnosed with PE-DLBCL between January 2015 and December 2020.

RESULTS

The gastrointestinal tract showed the highest rate of involvement (34%), followed by the central nervous system (CNS) and intraocular system (31.5%). The 3-year overall survival (OS) rate was 81% for the entire group and 79% for those with CNS and vitreoretinal involvement. Ann Arbour stage, lactate dehydrogenase level, International Prognostic Index > 2, and complete remission (CR) were significantly related to the survival of patients with PE-DLBCL. The lack of CR was the only independent adverse prognostic factor for OS.

CONCLUSION

The clinical outcomes of patients with PE-DLBCL at our centre were encouraging, especially for patients with CNS and vitreoretinal involvement.

SOHO State of the Art Updates and Next Questions: Prophylaxis and Management of Secondary CNS Lymphoma

Secondary CNS lymphoma (SCNSL) is a rare but frequently fatal complication of systemic lymphoma. There is no standard treatment for SCNSL, and patients who develop SCNSL at diagnosis or after frontline therapy often receive highly intensive chemotherapy regimens that are inactive against primary chemorefractory disease and too toxic for older, frail patients to tolerate. Because the prognosis of SCNSL is so poor, management has historically emphasized prevention, but the current methods of CNS prophylaxis are not universally effective. To improve both the prevention and management of SCNSL, better characterization of the molecular determinants of CNS invasion is needed. Novel treatments that are currently being studied in SCNSL include targeted pathway inhibitors and cellular therapy, but SCNSL patients are often excluded from clinical trials of promising new therapies.

IRF4 as an Oncogenic Master Transcription Factor

Simple Summary

Master transcription factors regulate essential developmental processes and cellular maintenance that characterize cell identity. Many of them also serve as oncogenes when aberrantly expressed or activated. IRF4 is one of prime examples of oncogenic master transcription factors that has been implicated in various mature lymphoid neoplasms. IRF4 forms unique regulatory circuits and induces oncogenic transcription programs through the interactions with upstream pathways and binding partners.

Abstract

IRF4 is a transcription factor in the interferon regulatory factor (IRF) family. Since the discovery of this gene, various research fields including immunology and oncology have highlighted the unique characteristics and the importance of IRF4 in several biological processes that distinguish it from other IRF family members. In normal lymphocyte development and immunity, IRF4 mediates critical immune responses via interactions with upstream signaling pathways, such as the T-cell receptor and B-cell receptor pathways, as well as their binding partners, which are uniquely expressed in each cell type. On the other hand, IRF4 acts as an oncogene in various mature lymphoid neoplasms when abnormally expressed. IRF4 induces several oncogenes, such as MYC, as well as genes that characterize each cell type by utilizing its ability as a master regulator of immunity. IRF4 and its upstream factor NF-κB form a transcriptional regulatory circuit, including feedback and feedforward loops, to maintain the oncogenic transcriptional program in malignant lymphoid cells. In this review article, we provide an overview of the molecular functions of IRF4 in mature lymphoid neoplasms and highlight its upstream and downstream pathways, as well as the regulatory circuits mediated by IRF4.

Lenalidomide plus R-GDP (R2-GDP) in Relapsed/Refractory Diffuse Large B-Cell Lymphoma: Final Results of the R2-GDP-GOTEL Trial and Immune Biomarker Subanalysis

PURPOSE

New therapeutic options are needed in relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL). Lenalidomide-based schedules can reverse rituximab refractoriness in lymphoma.

PATIENTS AND METHODS

In the phase II R2-GDP trial, 78 patients unsuitable for autologous stem cell transplant received treatment with the following schedule: lenalidomide 10 mg Days (D)1-14, rituximab 375 mg/m2 D1, cisplatin 60 mg/m2 D1, gemcitabine 750 mg/m2 D1 and D8, and dexamethasone 20 mg D1-3, up to 6 cycles (induction phase), followed by lenalidomide 10 mg (or last lenalidomide dose received) D1-21 every 28 days (maintenance phase). Primary endpoint was overall response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), safety, and monitorization of key circulating immune biomarkers (EU Clinical Trials Register number: EudraCT 2014-001620-29).

RESULTS

After a median follow-up of 37 months, ORR was 60.2% [37.1% complete responses (CR) and 23.1% partial responses (PR)]. Median OS was 12 months (47 vs. 6 months in CR vs. no CR); median PFS was 9 months (34 vs. 5 months in CR vs. no CR). In the primary refractory population, ORR was 45.5% (21.2% CR and 24.3% PR). Most common grade 3-4 adverse events were thrombocytopenia (60.2%), neutropenia (60.2%), anemia (26.9%), infections (15.3%), and febrile neutropenia (14.1%). Complete responses were associated with a sharp decrease in circulating myeloid-derived suppressor cells and regulatory T cells.

CONCLUSIONS

R2-GDP schedule is feasible and highly active in R/R DLBCL, including the primary refractory population. Immune biomarkers showed differences in responders versus progressors.

Double-drug loading upconversion nanoparticles for monitoring and therapy of a MYC/BCL6-positive double-hit diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a systemic hematological malignancy. Herein, through whole exome sequencing (WES), we found that DLBCL genome changes and expression characteristics are associated with various immune cells. Lenalidomide (Len) is a leading candidate for the immunomodulatory treatment of multiple myeloma in the clinic. Inspired by lenalidomide as an immunomodulatory drug for the treatment of multiple myeloma, we constructed a multifunctional nanoplatform with therapeutic and imaging properties for DLBCL by co-loading lenalidomide and dexamethasone (Dex) with upconversion nanoparticles using a GSH-sensitive linker (named as UCNPs-Len-Dex). In vitro cell experiments proved that the UCNPs-Len-Dex had good biocompatibility and obvious antitumor efficacy. UCNPs-Len-Dex also exhibited excellent anti-tumor efficacy and imaging properties in vivo. RNA sequencing showed that UCNPs-Len-Dex targeted and activated the E3 ligase of CRBN, resulting in IKZF1/3 degradation, which inhibited MYC/BCL6-positive DLBCL and maintained the stability of the immune microenvironment. Therefore, this study provided a new monitoring and therapeutic synergetic strategy for DLBCL.

Lineage- and Stage-specific Oncogenicity of IRF4

Dysregulation of transcription factor genes represents a unique molecular etiology of hematological malignancies. A number of transcription factors that play a role in hematopoietic cell development, lymphocyte activation or their maintenance have been identified as oncogenes or tumor suppressors. Many of them exert oncogenic abilities in a context-dependent manner by governing the key transcriptional program unique to each cell type. IRF4, a member of the interferon regulatory factor (IRF) family, acts as an essential regulator of the immune system and is a prime example of a stage-specific oncogene. The expression and oncogenicity of IRF4 are restricted to mature lymphoid neoplasms, while IRF4 potentially serves as a tumor suppressor in other cellular contexts. This is in marked contrast to its immediate downstream target, MYC, which can cause cancers in a variety of tissues. In this review article, we provide an overview of the roles of IRF4 in the development of the normal immune system and lymphoid neoplasms and discuss the potential mechanisms of lineage- and stage-specific oncogenicity of IRF4.

Pemetrexed Plus Lenalidomide for Relapsed/Refractory Primary Central Nervous System Lymphoma: A Prospective Single-Arm Phase II Study

The prognosis of relapsed/refractory (R/R) primary central nervous system lymphoma (PCNSL) is dismal, and there are limited treatment options for these patients. This was a prospective single-arm phase II study of combined pemetrexed and lenalidomide for salvage treatment of R/R PCNSL. Patients with R/R PCNSL (n = 38) who had undergone two or more different therapeutic regimens and experienced disease progression or recurrence were enrolled. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression-free survival (PFS) and overall survival (OS). Patients were followed up for a median of 18 (range, 1–36) months. ORR was 68.4%, with median PFS and OS of 6 and 18 months, respectively. Adverse events (AEs) included myelosuppression, fatigue, nausea, fever, infection, cardiac disease, and thrombogenesis. Commonly observed grade ≥ 3 AEs included neutropenia (5.3%), leukopenia (2.6%), thrombocytopenia (7.9%), and infection (2.6%). Elevated lactate dehydrogenase (LDH) levels (χ2 = 13.25; P = 0.0003) and bulky disease (P = 0.032; χ2 = 4.580) were associated with short PFS. Elevated serum LDH level (P = 0.011; χ2 = 6.560), abnormal lymphoma cells in the cerebrospinal fluid (CSF) [P = 0.011; χ2 = 6.445], and multiple lesions (P = 0.036; χ2 = 4.404) were significantly associated with poorer OS. Abnormal lymphoma cells in the CSF were an independent predictor of poor prognosis on multivariate analysis (P = 0.034; hazard ratio (HR) = 2.836; 95% confidence interval, 1.082–7.434). Our results indicate that pemetrexed plus lenalidomide is effective for heavily treated R/R PCNSL, with moderate toxicity. Trial registration: #ChiCTR1900028070.

EBV-positive diffuse large B-cell lymphoma, not otherwise specified: 2022 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

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

DIAGNOSIS

The diagnosis is made through a careful pathological evaluation. Detection of EBV-encoded RNA (EBER) is considered standard for diagnosis; however, a clear cutoff for percentage of positive cells has not been defined. The differential diagnosis includes plasmablastic lymphoma (PBL), DLBCL associated with chronic inflammation, primary effusion lymphoma (PEL), among others.

RISK-STRATIFICATION

The International Prognostic Index (IPI) and the Oyama score can be used for risk-stratification. The Oyama score includes age >70 years and presence of B symptoms. The expression of CD30 and PD-1/PD-L1 are emerging as potential adverse but targetable biomarkers.

MANAGEMENT

Patients with EBV+ DLBCL, NOS, should be staged and managed following similar guidelines than patients with EBV-negative DLBCL. EBV+ DLBCL, NOS, however, might have a worse prognosis than EBV-negative DLBCL in the era of chemoimmunotherapy. Therefore, the inclusion of patients in clinical trials when available is recommended. There is an opportunity to study and develop targeted therapy in the management of patients with EBV+ DLBCL, NOS.

Immunophenotypic Landscape and Prognosis-Related mRNA Signature in Diffuse Large B Cell Lymphoma

Diffuse large B cell lymphoma (DLBCL) exhibits a tightly complexity immune landscape. In this study, we intended to identify different immune phenotype and to examine the immune related mRNA signature for clinical characteristic, therapeutic responsiveness as well as risk stratification and survival prediction in DLBCL. We identified two immune infiltration subtypes of DLBCL patients based on 28 immune cell types. GSEA analysis uncovered the concordant classification of two robust significant subtypes of DLBCL. Considering the convenient application of the immune infiltration subtypes for prognostic prediction, we developed a risk score based on the differentially expressed genes between the Immunity-H and Immunity-L groups. By a least absolute shrinkage and selection operator (LASSO)-Cox regression model, a sixteen-gene risk signature, comprising ANTXR1, CD3D, TIMP1, FPR3, NID2, CTLA4, LPAR6, GPR183, LYZ, PTGDS, ITK, FBN1, FRMD6, PLAU, MICAL2, C1S, was established. The comprehensive results showed that the high-risk group was correlated with lower immune infiltration, more aggressive phenotypes, lower overall survival and more sensitive to lenalidomide. In contrast, a low-risk group score was associated with higher immune infiltration, less aggressive phenotypes, better overall survival and more likely to benefit from PD-1/PD-L1 inhibitors. Finally, a nomogram comprised of the risk score and IPI score was verified to more accurately predict the overall survival of DLBCL than traditional clinical prediction models. Altogether, our data demonstrate the heterogeneity of immune patterns within DLBCL and deepen our molecular understanding of this tumor entity.

Phase 1/dose expansion trial of brentuximab vedotin and lenalidomide in relapsed or refractory diffuse large B-cell lymphoma

New therapies are needed for patients with relapsed/refractory (rel/ref) diffuse large B-cell lymphoma (DLBCL) who do not benefit from or are ineligible for stem cell transplant and chimeric antigen receptor therapy. The CD30-targeted, antibody-drug conjugate brentuximab vedotin (BV) and the immunomodulator lenalidomide (Len) have demonstrated promising activity as single agents in this population. We report the results of a phase 1/dose expansion trial evaluating the combination of BV/Len in rel/ref DLBCL. Thirty-seven patients received BV every 21 days, with Len administered continuously for a maximum of 16 cycles. The maximum tolerated dose of the combination was 1.2 mg/kg BV with 20 mg/d Len. BV/Len was well tolerated with a toxicity profile consistent with their use as single agents. Most patients required granulocyte colony-stimulating factor support because of neutropenia. The overall response rate was 57% (95% CI, 39.6-72.5), complete response rate, 35% (95% CI, 20.7-52.6); median duration of response, 13.1 months; median progression-free survival, 10.2 months (95% CI, 5.5-13.7); and median overall survival, 14.3 months (95% CI, 10.2-35.6). Response rates were highest in patients with CD30+ DLBCL (73%), but they did not differ according to cell of origin (P = .96). NK cell expansion and phenotypic changes in CD8+ T-cell subsets in nonresponders were identified by mass cytometry. BV/Len represents a potential treatment option for patients with rel/ref DLBCL. This combination is being further explored in a phase 3 study (registered on https://clinicaltrials.org as NCT04404283). This trial was registered on https://clinicaltrials.gov as NCT02086604.

Management of relapsed or refractory large B-cell lymphoma in patients ineligible for CAR-T cell therapy

INTRODUCTION

Chimeric antigen receptor T (CAR-T) therapy has revolutionized the treatment of relapsed/refractory large B-cell lymphoma (LBCL). However, patients who are excluded or have no access to CAR-T represent a challenge for clinicians and have generally a dismal outcome. The landscape for this category of patients is constantly evolving: new agents have been approved in the last 2-3 years, alone or in combination, and novel treatment modalities are under investigations.

AREAS COVERED

Thereafter, we reviewed the currently available therapeutic strategies: conventional chemotherapy, Antibody-drug conjugate ADC (mainly polatuzumab and loncastuxumab), bispecific antibodies (CD19/CD3 and focus on novel CD20/CD3 Abs), immunomodulatory drugs (covering tafasitamab and lenalidomide, checkpoint inhibitors mainly in PMBL), small molecules (selinexor, BTK and PI3K inhibitors), and the role of radiotherapy.

EXPERT OPINION

Navigating this scenario, will uncover new challenges, including identifying an ideal sequence for these therapies, the most effective combinations, and search for consistent predictive factors to help selecting the appropriate population of LBCL patients. At present, supporting clinical research for CAR-T ineligible patients, a new and challenging group, must remain a major focus that is complementary to advances in CAR T-cell therapy.

MYD88L265P and CD79B double mutations type (MCD type) of diffuse large B-cell lymphoma: mechanism, clinical characteristics, and targeted therapy

MYD88/CD79B-mutated (MCD) genotype is a genetic subgroup of diffuse large B-cell lymphoma (DLBCL) with the co-occurrence of MYD88^L265P and CD79B mutations. MCD genotype is characterized by poor prognosis and extranodal involvement especially in immune-privileged sites. MCD model is dominated by activated B-cell (ABC)-like subtype of DLBCLs. It is generally accepted that the pathogenesis of MCD DLBCL mainly includes chronic active B-cell receptor (BCR) signaling and oncogenic MYD88 mutations, which drives pathological nuclear factor kappa B (NF-κB) activation in MCD lymphoid malignancies. CD79B and MYD88^L265P mutations are frequently and contemporaneously founded in B-cell malignancies. The collaboration of the two mutations may explain the unique biology of MCD. Meanwhile, standard immunochemotherapy combine with different targeted therapies worth further study to improve the prognosis of MCD, according to genetic, phenotypic, and clinical features of MCD type. In this review, we systematically described mechanism, clinical characteristics, and targeted therapy of MCD DLBCL.

Efficacy and Safety of Lenalidomide Monotherapy for Relapsed/Refractory Diffuse Large B Cell Lymphoma: Systematic Review and Meta-Analysis

INTRODUCTION

Several maintenance therapies are available for treatment of patients with relapsed/refractory (R/R) diffuse large B cell lymphoma (DLBCL). The objective of this review was to assess the efficacy and safety of lenalidomide monotherapy in these patients.

METHODS

MEDLINE, EMBASE, and the Cochrane Library databases were searched for publications up to April 7, 2021. Original studies that had information on lenalidomide monotherapy for DLBCL patients with R/R status were included. Meta-analyses of response rates, adverse events (AEs), overall survival (OS), and progression-free survival (PFS) were performed. The pooled event rates were calculated using a double arcsine transformation to stabilize the variances of the original proportions. Subgroup analysis was used to compare patients with different germinal center B-cell-like (GCB) phenotypes.

RESULTS

We included 11 publications that examined DLBCL patients with R/R status. These studies were published from 2008 to 2020. The cumulative objective response rate (ORR) for lenalidomide monotherapy was 0.33 (95% CI: 0.26, 0.40), and the ORR was better in patients with the non-GCB phenotype (0.50; 95% CI: 0.26, 0.74) than the GCB phenotype (0.06; 95% CI: 0.03, 0.11). The major serious treatment-related AEs were neutropenia, thrombocytopenia, respiratory disorders, anemia, and diarrhea. The median PFS ranged from 2.6 to 34 months and the median OS ranged from 7.8 to 37 months.

CONCLUSION

This study provides evidence that lenalidomide monotherapy was active and tolerable in DLBCL patients with R/R status. Patients in the non-GCB subgroup had better responsiveness.

Zanubrutinib Monotherapy for Relapsed or Refractory Non-Germinal Center Diffuse Large B-Cell Lymphoma

Modest responses and antitumor activity were observed with zanubrutinib monotherapy in patients with non-GCB DLBCL.

Potential antitumor activity was observed in DLBCL with mutations in both CD79B and MYD88 genes.

The non-germinal center B-cell like (non-GCB) subtype of diffuse large B-cell lymphoma (DLBCL) has poor clinical outcomes. Bruton tyrosine kinase (BTK) inhibitors have established therapeutic activity in B-cell malignancies, with modest activity in DLBCL. Zanubrutinib, a potent and selective BTK inhibitor, was evaluated in patients with relapsed or refractory (R/R) non-GCB DLBCL. The BGB-3111-207 study (NCT03145064) was a multicenter single-arm phase 2 study. Patients received twice-daily oral zanubrutinib, 160 mg, until disease progression or unacceptable toxicity. The primary end point was the overall response rate (ORR). Secondary end points included progression-free survival (PFS) and duration of response (DOR). Overall survival (OS) was an exploratory end point. Forty-one patients were enrolled in China after having progressed or not responded to prior therapy. At data cutoff, 4 patients continued treatment with 37 discontinuations. The median follow-up was 6.8 months, the ORR was 29.3%, and the complete response rate was 17.1%. Median DOR, PFS, and OS were 4.5, 2.8, and 8.4 months, respectively. Adverse events (AEs) leading to treatment discontinuation were reported in 4 patients, and grade ≥ 3 AEs were reported in 48.8% of patients. Major hemorrhage, atrial fibrillation, and/or flutter were not observed. Zanubrutinib demonstrated modest antitumor activity in non-GCB DLBCL, like other BTK inhibitors, as well as a safety profile consistent with previous studies. Through retrospective biomarker testing, potential antitumor activity was observed in patients with both CD79B and MYD88 mutations, who have inferior outcomes to immunochemotherapy. Future studies of zanubrutinib in R/R non-GCB DLBCL will focus on developing mechanism-based treatment combinations and biomarker-driven patient selection.

Romidepsin and lenalidomide-based regimens have efficacy in relapsed/refractory lymphoma: Combined analysis of two phase I studies with expansion cohorts

Romidepsin (histone deacetylase inhibitor), lenalidomide (immunomodulatory agent), and carfilzomib (proteasome inhibitor), have efficacy and lack cumulative toxicity in relapsed/refractory lymphoma. We performed two investigator initiated sequential phase I studies to evaluate the maximum tolerated dose (MTD) of romidepsin and lenalidomide (regimen A) and romidepsin, lenalidomide, and carfilzomib (regimen B) in relapsed/refractory lymphoma. Cohorts in T-cell lymphoma (TCL), B-cell lymphoma (BCL) were enrolled at the MTD. Forty-nine patients were treated in study A (27 TCL, 17 BCL, 5 Hodgkin lymphoma (HL)) and 27 (16 TCL, 11 BCL) in study B. The MTD of regimen A was romidepsin 14 mg/m² IV on days 1, 8, and 15 and lenalidomide 25 mg oral on days 1-21 of a 28-day cycle. The MTD of regimen B was romidepsin 8 mg/m² on days 1 and 8, lenalidomide 10 mg oral on days 1-14 and carfilzomib 36 mg/m² IV on days 1 and 8 of a 21-day cycle. In study A, 94% had AEs ≥Grade 3, most commonly neutropenia (49%), thrombocytopenia (53%), and electrolyte abnormalities (49%). In study B 59% had AEs ≥Grade 3, including thrombocytopenia (30%) and neutropenia (26%). In study A the ORR was 49% (50% TCL, 47% BCL, 50% HL). In study B the ORR was 48% (50% TCL, 50% BCL). For study A and B the median progression free survival (PFS) was 5.7 months and 3.4 months respectively with 11 patients proceeding to allogeneic transplant. The combinations of romidepsin and lenalidomide and of romidepsin, lenalidomide and carfilzomib showed activity in relapsed/refractory lymphoma with an acceptable safety profile.

Lenalidomide in combination with R-CHOP produces high response rates and progression-free survival in new, untreated diffuse large B-cell lymphoma transformed from follicular lymphoma: results from the Phase 2 MC078E study

Diffuse large B-cell lymphoma (DLBCL), either concurrent with or transformed from follicular lymphoma (FL) is often excluded from clinical trials. Lenalidomide has response rates of 45% in relapsed transformed DLBCL. Herein we present an analysis of MC078E, a phase II clinical trial testing lenalidomide plus R-CHOP (R2CHOP) for patients with untreated transformed/concurrent DLBCL (NCT00670358). Adult patients with transformed or concurrent DLBCL were included. Patients received six cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP) with lenalidomide 25 mg days 1-10 of each cycle. The primary outcome was progression-free survival (PFS) at 24 months. Secondary outcomes were response rates, event-free survival (EFS), and overall survival (OS). Thirty-nine patients were accrued from August 5, 2013 to July 28, 2020 and 33 were eligible by central pathology review. The median age was 64 (24-80) years, 18 (54%) were male, 25 (76%) were concurrent and 8 (24%) were transformed DLBCL. The PFS, EFS, and OS rates at 24 months were 84.4% (CI₉₅: 67.2-94.7%), 84.5% (CI₉₅: 72.9-98%), and 97.0% (CI₉₅: 91.3-100%), respectively. R2CHOP is effective in concurrent and transformed DLBCL. The study supports the inclusion of anthracycline-naive transformed and concurrent DLBCL in future clinical trials of novel immunomodulatory analogues.

Phase 1b/2 study of ibrutinib and lenalidomide with dose-adjusted EPOCH-R in patients with relapsed/refractory diffuse large B-cell lymphoma

Relapsed/refractory diffuse large B-cell lymphoma (DLBCL) is difficult to cure; non-germinal center B-cell-like (non-GCB) and activated B-cell-like (ABC) DLBCL have worse outcomes than GCB DLBCL. Ibrutinib and lenalidomide are synergistic in vitro in ABC DLBCL and may augment salvage chemotherapy. In part 1 of this phase 1b/2 study (NCT02142049), patients with relapsed/refractory DLBCL received ibrutinib 560 mg and escalating doses of lenalidomide on Days 1-7 with DA-EPOCH-R (Days 1-5) in 21-day cycles. In part 1 (N = 15), the maximum tolerated dose was not reached with lenalidomide 25 mg (recommended part 2 dose [RP2D]); most common grade ≥3 adverse events were anemia (73%) and febrile neutropenia (47%); the overall response rate (ORR) was 40%. At the RP2D (n = 26), ORR was 71% in non-GCB and 64% in ABC. Ibrutinib and lenalidomide with DA-EPOCH-R had a manageable safety profile and antitumor activity in relapsed/refractory DLBCL, especially the non-GCB subtype.

Combination of novel molecular targeted agent plus R-CHOP-based regimen versus R-CHOP alone in previously untreated diffuse large B-cell lymphoma (DLBCL) patients: a systematic review and meta-analysis

The addition of molecular targeted agents (MTAs) to R-CHOP has been one of the main focuses of research in patients with DLBCL. Despite encouraging preliminary results, recent randomized controlled trials (RCT) have not shown a definitive benefit over standard R-CHOP. Here we conducted a systematic review and meta-analysis to investigate the impact of this strategy. A systematic literature review was conducted to identify RCT that evaluated the addition of MTA to R-CHOP-based regimen versus R-CHOP alone in previously untreated DLBCL patients. Fixed and random effects models were used to estimate pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CI). Progression-free survival (PFS), overall survival, and adverse events (AE) were analyzed. A total of seven RCT including 3,255 patients with DLBCL met the eligibility criteria. Three different types of MTAs (bortezomib, ibrutinib, and lenalidomide) were investigated in combination with R-CHOP. Overall, R-CHOP plus MTA showed a slightly better PFS (HR=0.86; 95% CI: 0.76-0.98). No differences were observed according to the cell of origin subtype of DLBCL. Interestingly, patients younger than 60 years had a significantly better PFS with R-CHOP plus MTAs (HR=0.72; 95% CI: 0.56-0.93), while no benefit was observed in patients older than 60 years (HR=0.96). The combination strategy showed higher odds to develop serious AEs (OR= 1.46, 95% CI 1.11-1.91). R-CHOP plus MTA seems only to slightly improve PFS in patients with DLBCL, particularly in younger patients. An increase in toxicity was observed in comparison to R-CHOP.

Immunomodulatory Drugs for the Treatment of B Cell Malignancies

Accumulating evidence suggests that the tumor microenvironment (TME) is involved in disease progression and drug resistance in B cell malignancies, by supporting tumor growth and facilitating the ability of malignant cells to avoid immune recognition. Immunomodulatory drugs (IMiDs) such as lenalidomide have some direct anti-tumor activity, but critically also target various cellular compartments of the TME including T cells, NK cells, and stromal cells, which interfere with pro-tumor signaling while activating anti-tumor immune responses. Lenalidomide has delivered favorable clinical outcomes as a single-agent, and in combination therapy leads to durable responses in chronic lymphocytic leukemia (CLL) and several non-Hodgkin lymphomas (NHLs) including follicular lymphoma (FL), diffuse large B cell lymphoma (DLBCL), and mantle cell lymphoma (MCL). Recently, avadomide, a next generation cereblon E3 ligase modulator (CELMoD), has shown potent anti-tumor and TME immunomodulatory effects, as well as promising clinical efficacy in DLBCL. This review describes how the pleiotropic effects of IMiDs and CELMoDs could make them excellent candidates for combination therapy in the immuno-oncology era-a concept supported by preclinical data, as well as the recent approval of lenalidomide in combination with rituximab for the treatment of relapsed/refractory (R/R) FL.

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.

Primary vitreoretinal lymphoma: A diagnostic and management challenge

Primary vitreoretinal lymphoma (PVRL) is a rare form of primary central nervous system lymphoma (PCNSL) arising in the intraocular compartment without brain involvement. Despite its apparent indolent clinical course, PVRL can cause permanent vision loss and CNS relapse, the major cause of death in PVRL patients. The pathophysiology of PVRL is unknown. As in PCNSL, the transformation of the tumor cells likely originates outside the CNS, before the cells migrate to the eye and proliferate within an immune-permissive microenvironment. PVRL exhibits a biased immunoglobulin repertoire, suggesting underlying antigen selection. The diagnosis remains challenging, requiring close coordination between ophthalmologists and cytologists. Because of their rarity and fragility in the vitreous, lymphoma cells cannot always be identified. Interleukin levels, molecular biology and imaging are used in combination with clinical ophthalmological examination to support the diagnosis of PVRL. Multi-institutional prospective studies are urgently needed to validate the equivocal conclusions regarding treatments drawn from heterogeneous retrospective or small cohort studies. Intravitreal injections of methotrexate or rituximab or local radiotherapy are effective at clearing tumor cells within the eyes but do not prevent CNS relapse. Systemic treatment based on high-dose methotrexate chemotherapy, with or without local treatment, might reduce this risk. At relapse, intensive consolidation chemotherapy followed by stem cell transplantation can be considered. Single-agent ibrutinib, lenalidomide and temozolomide treatments are effective in patients with relapsed PVRL and should be tested as first-line treatments. Therapeutic response assessment based on a clinical examination is improved by measuring cytokine levels but still needs to be refined.

Molecular Classification and Treatment of Diffuse Large B-Cell Lymphoma and Primary Mediastinal B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) encompasses a group of aggressive B-cell non-Hodgkin lymphomas with striking genetic heterogeneity and variable clinical presentations. Among these is primary mediastinal B-cell lymphoma (PMBL), which has unique clinical and molecular features resembling Hodgkin lymphoma. Treatment of DLBCL is usually curative, but identifiable subsets at highest risk for treatment failure may benefit from intensified chemotherapy regimens and/or targeted agents added to frontline therapy. Recent comprehensive genomic analyses have identified distinct genetic subtypes of DLBCL with characteristic genetic drivers and signaling pathways that are targetable. Immune therapy with chimeric antigen receptor T cells and checkpoint inhibitors has revolutionized the treatment of relapsed or refractory disease, and antibody drug conjugates have weaponized otherwise intolerable cytotoxic agents. Ongoing clinical trials are further refining the specificity of these approaches in different genetic subtypes and moving them from the setting of recurrent disease to frontline treatment in high-risk patient populations.

ROBUST: A Phase III Study of Lenalidomide Plus R-CHOP Versus Placebo Plus R-CHOP in Previously Untreated Patients With ABC-Type Diffuse Large B-Cell Lymphoma

Patients with the activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) historically showed inferior survival with standard rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Phase II studies demonstrated that adding the immunomodulatory agent lenalidomide to R-CHOP improved outcomes in ABC-type DLBCL. The goal of the global, phase III ROBUST study was to compare lenalidomide plus R-CHOP (R2-CHOP) with placebo/R-CHOP in previously untreated, ABC-type DLBCL.

ADCs, BiTEs, CARs, and Small Molecules: A New Era of Targeted Therapy in Non-Hodgkin Lymphoma

Novel immunotherapies and small molecular inhibitors are transforming our approach to previously treated and newly diagnosed patients across the spectrum of non-Hodgkin lymphomas (NHLs). Anti-CD19 CAR T cells are now indicated for the treatment of relapsed/refractory aggressive B-cell lymphomas after at least two previous lines of therapy in which durable remissions are achieved in approximately 40% of previously incurable patients. Second-line chemoimmunotherapy remains the standard of care at first relapse, but poor outcomes with conventional treatment in this setting creates an appealing rationale for earlier use of CAR T cells, which is currently under investigation, along with even earlier use in selected high-risk patients in the frontline setting. Other emerging immunotherapies include antibody-drug conjugates (ADCs), such as polatuzumab vedotin for multiple-relapsed diffuse large B-cell lymphoma (DLBCL) in combination with bendamustine-rituximab. Multiple bispecific antibodies that bring malignant B cells in contact with effector T cells appear promising in early clinical trials and will likely emerge as off-the-shelf immunotherapy options. Chemotherapy-free small molecule-based regimens are increasingly available for mantle cell (MCLs) and follicular lymphomas (FLs). Bruton tyrosine kinase inhibitors (BTKi) now represent standard second-line therapy for MCL and are being investigated in combination and as initial therapy. Lenalidomide-rituximab is an active regimen in both FL and MCL and may be used in either relapsed/refractory or previously untreated disease. Three PI3K inhibitors are approved for multiple-relapsed FL and can induce durable remissions in patients with chemotherapy- and rituximab-refractory disease. Additional emerging targeted therapies include BCL2 inhibition in MCL and EZH2 inhibition in FL.

Treatment of Aggressive B Cell Lymphomas: Updates in 2019

PURPOSE OF REVIEW

Recent years have seen the development of gene expression profiling and next-generation sequencing in diffuse large B cell lymphoma (DLBCL), leading to a more defined characterization of this disease into distinct subentities. The genomic era has ushered in the possibility of using precision guided therapy, in part based on targeting genes with somatic mutations. Such precision-targeted therapies will ultimately reduce the need for chemotherapy, induce fewer adverse events, and likely enhance the cure rate for these patients. Here, we discuss emerging therapeutic strategies that have been recently developed for the upfront and relapse setting of DLBCL.

RECENT FINDINGS

Clinical trials exploring precision medicine have showed promising results; however, attempts to enhance frontline immunochemotherapy by adding targeted agents to the R-CHOP backbone did not confirm the expected benefit. The last decade has also seen a revolutionary development of immunotherapy in B cell lymphomas. While cellular immunotherapy demonstrated a striking success of CAR T cells in DLBCL, checkpoint inhibitors have lacked success in B cell lymphomas. A parallel therapeutic expansion has involved bispecific monoclonal antibodies as a powerful tool for redirected T cell therapy independently from costimulatory molecules and major-histocompatibility complex. The landscape of drugs for the treatment of DLBCL has become overwhelmed by the increasing number of targeted and immunological therapies; however, none have enhanced efficacy of frontline therapy. Future direction should focus to redefine therapeutic paradigm and develop mechanism-based combinatorial regimens specifically tailored for DLBCL genetic subgroups.

Local Investigators Significantly Overestimate Overall Response Rates Compared to Blinded Independent Central Reviews in Phase 2 Oncology Trials

The overall response rate (ORR) is a largely adopted outcome measure in early-phase oncology trials. ORR is highly relevant in cancer drug development at the time of deciding whether to move to confirmatory phase 3 trials; moreover, ORR is gaining increasing relevance in fast-track registration procedures. No systematic analysis has been conducted so far to investigate whether a discrepancy exists between ORR assessed by local investigators and those assessed by blinded reviewers in phase 2 oncology trials. In this study, we carried out a search in the clinicaltrials.gov and EudraCT databases, looking at the trials reporting the results of both investigator-assessed and independently-assessed ORR. A discrepancy index was obtained by calculating the ratio of each investigator-assessed ORR on the corresponding independently assessed ORR, so that a discrepancy index >1 indicates that the investigator was "more optimistic," whereas a discrepancy index <1 indicates the opposite. We also analyzed different subgroups (by tumor type, by drug type, by year). Twenty trials met the search criteria; in some cases, >1 comparison was conducted in the trial, so that the total number of comparisons analyzed was 33. The estimated mean discrepancy index was 1.175 (95% confidence interval, 1.083-1.264; n = 33). In conclusion, local investigators significantly overestimate ORR compared to paired blinded reviewers in phase 2 oncology trials. This may represent a risk in drug development, when deciding whether to move to confirmatory, more expensive phase 3 trials. Blinded independent central review should be used in ORR assessment if a more conservative estimate of treatment efficacy is required, as in the case of fast-track drug developments leading to accelerated approvals of cancer therapies.

New agents and regimens for diffuse large B cell lymphoma

As a widely recognized standard regimen, R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) is able to cure two-thirds patients with diffuse large B cell lymphoma (DLBCL), and the remaining patients suffer from refractory or relapsed disease due to resistance to R-CHOP and fare poorly. Unsatisfied outcomes for those relapsed/refractory patients prompted efforts to discover new treatment approaches for DLBCL, including chimeric antigen receptor T cells, bispecific T cell engagers, immunomodulatory drugs, immune checkpoint inhibitors, monoclonal antibodies, antibody-drug conjugates, molecular pathway inhibitors, and epigenetic-modifying drugs. Herein, up-to-date data about the most promising treatment approaches for DLBCL are recapitulated, and novel genetic classification systems are introduced to guide individualized treatment for DLBCL.

Primary Central Nervous System Lymphoma: Evolving Biologic Insights and Recent Therapeutic Advances

Primary central nervous system lymphoma (PCNSL) is a rare and clinically aggressive disease entity associated with poor survival. Though high-dose methotrexate-based immunochemotherapy approaches are effective at inducing responses, few patients experience long-term durable remissions. Recently, novel insights into the biology of this unique disease have been elucidated and have paved the way for the investigation of rational approaches such as Bruton tyrosine kinase inhibition and immunomodulation. Although these strategies can induce high response rates in PCNSL, remissions are short lived, with median progression-free survivals in the range of 6 months or less. Moving forward, understanding the mechanisms of treatment resistance with these and other novel agents is key to developing optimal combinatorial strategies. New approaches such as immune checkpoint inhibition and chimeric antigen receptor T-cell therapy are under investigation for PCNSL and thus far demonstrate activity in anecdotal clinical experiences. Future trials should focus on investigating novel rational combinations designed to optimally target the biology of PCNSL and simultaneously investigate mechanisms of resistance leading to treatment failure.

Pathobiology and treatment of lymphomatoid granulomatosis, a rare EBV-driven disorder

Lymphomatoid granulomatosis (LYG) is a rare Epstein-Barr virus (EBV)-driven B-cell lymphoproliferative disease (LPD). This disease is hypothesized to result from defective immune surveillance of EBV, with most patients showing evidence of immune dysfunction, despite no known primary immunodeficiency. Pathologically, LYG is graded by the number and density of EBV+ atypical B cells, and other characteristic findings include an angioinvasive/angiodestructive reactive T-cell infiltrate and various degrees of necrosis. Clinically, LYG universally involves the lungs with other common extranodal sites, including skin, central nervous system, liver, and kidneys. Nodal and/or bone marrow involvement is extremely rare and, if present, suggests an alternative diagnosis. Treatment selection is based on histologic grade and underlying pathobiology with low-grade disease hypothesized to be immune-dependent and typically polyclonal and high-grade disease to be immune-independent and typically oligoclonal or monoclonal. Methods of augmenting the immune response to EBV in low-grade LYG include treatment with interferon-α2b, whereas high-grade disease requires immunochemotherapy. Given the underlying defective immune surveillance of EBV, patients with high-grade disease may have a recurrence in the form of low-grade disease after immunochemotherapy, and those with low-grade disease may progress to high-grade disease after immune modulation, which can be effectively managed with crossover treatment. In patients with primary refractory disease or in those with multiple relapses, hematopoietic stem cell transplantation may be considered, but its efficacy is not well established. This review discusses the pathogenesis of LYG and highlights distinct histopathologic and clinical features that distinguish this disorder from other EBV+ B-cell LPDs and lymphomas. Treatment options, including immune modulation and combination immunochemotherapy, are discussed.

Successful treatment with lenalidomide plus chidamide combination therapy in 3 heavily treated patients with non-Hodgkin lymphoma: Three cases report

RATIONALE

The prognosis of patients with aggressive relapsed or refractory (R/R) non-Hodgkin lymphoma (NHL) remains poor. Both immunomodulatory drugs and histone deacetylase inhibitors have demonstrated activity against R/R NHL; yet, the combination of these 2 targeted therapies has rarely been explored.

PATIENT CONCERNS

Here, we report 3 cases. Case 1 was a 68-year-old woman who presented to our hospital with dyspnea. Case 2 was a 75-year-old man with massive upper gastrointestinal bleeding. Case 3 was a 62-year-old woman with cough, dyspnea, and lymphadenopathy.

DIAGNOSIS

The biopsy results revealed diffuse large B cell lymphoma (DLBCL), DLBCL, and angioimmunoblastic T-cell lymphoma, for Case 1, 2, and 3 respectively.

INTERVENTION

All 3 patients experienced relapse after first-line therapy and multiple lines of salvage therapy. Finally, they all received lenalidomide combined with chidamide.

OUTCOMES

All 3 patients achieved complete and durable remission. Case 1 relapsed again after 3 months, while the other 2 cases remained in complete remission.

LESSONS

To our knowledge, this is the first report of lenalidomide combined with chidamide for the treatment of R/R NHL. Our findings warrant further evaluation of this novel chemo-free therapy in future prospective clinical trials.