Safety and efficacy of parsaclisib in combination with rituximab, bendamustine + rituximab, or ibrutinib in patients with previously treated B-cell lymphoma: analysis of a phase 1 dose-finding study (CITADEL‑112)

Parsaclisib, a potent and highly selective phosphoinositide 3-kinase δ inhibitor, has shown clinical activity in relapsed/refractory (R/R) B-cell lymphoma. The phase 1 CITADEL-112 (NCT03424122) study assessed safety and efficacy of parsaclisib in combination with investigator choice standard of care (SOC; rituximab [Treatment A], rituximab plus bendamustine [Treatment B], or ibrutinib [Treatment C]) in 50 patients with R/R B-cell lymphoma. The most common treatment-emergent adverse events included neutropenia (62.5%, 50.0%, and 50.0% of patients in Treatments A, B, and C, respectively); diarrhea (37.5%) and anemia (31.3%) in Treatment A; abdominal pain, asthenia, diarrhea, and nausea (each 33.3%) in Treatment B; and increased alanine and aspartate aminotransferase (each 37.5%) in Treatment C. Objective responses were observed in 13 patients (81.3%) in Treatment A, 10 (55.6%) in Treatment B, and 8 (50.0%) in Treatment C. Parsaclisib combined with SOC therapies had an expected safety profile and promising efficacy in patients with R/R B-cell lymphomas.

Frequent ZNF217 mutations lead to transcriptional deregulation of interferon signal transduction via altered chromatin accessibility in B cell lymphoma

Recent exome-wide studies discovered frequent somatic mutations in the epigenetic modifier ZNF217 in primary mediastinal B cell lymphoma (PMBCL) and related disorders. As functional consequences of ZNF217 alterations remain unknown, we comprehensively evaluated their impact in PMBCL. Targeted sequencing identified genetic lesions affecting ZNF217 in 33% of 157 PMBCL patients. Subsequent gene expression profiling (n = 120) revealed changes in cytokine and interferon signal transduction in ZNF217-aberrant PMBCL cases. In vitro, knockout of ZNF217 led to changes in chromatin accessibility interfering with binding motifs for crucial lymphoma-associated transcription factors. This led to disturbed expression of interferon-responsive and inflammation-associated genes, altered cell behavior, and aberrant differentiation. Mass spectrometry demonstrates that ZNF217 acts within a histone modifier complex containing LSD1, CoREST and HDAC and interferes with H3K4 methylation and H3K27 acetylation. Concluding, our data suggest non-catalytic activity of ZNF217, which directs histone modifier complex function and controls B cell differentiation-associated patterns of chromatin structure.

The International Consensus Classification of Mature Lymphoid Neoplasms: a report from the Clinical Advisory Committee

Since the publication of the Revised European-American Classification of Lymphoid Neoplasms in 1994, subsequent updates of the classification of lymphoid neoplasms have been generated through iterative international efforts to achieve broad consensus among hematopathologists, geneticists, molecular scientists, and clinicians. Significant progress has recently been made in the characterization of malignancies of the immune system, with many new insights provided by genomic studies. They have led to this proposal. We have followed the same process that was successfully used for the third and fourth editions of the World Health Organization Classification of Hematologic Neoplasms. The definition, recommended studies, and criteria for the diagnosis of many entities have been extensively refined. Some categories considered provisional have now been upgraded to definite entities. Terminology for some diseases has been revised to adapt nomenclature to the current knowledge of their biology, but these modifications have been restricted to well-justified situations. Major findings from recent genomic studies have impacted the conceptual framework and diagnostic criteria for many disease entities. These changes will have an impact on optimal clinical management. The conclusions of this work are summarized in this report as the proposed International Consensus Classification of mature lymphoid, histiocytic, and dendritic cell tumors.

Genetic and phenotypic attributes of splenic marginal zone lymphoma

Splenic marginal zone B-cell lymphoma (SMZL) is a heterogeneous clinico-biological entity. The clinical course is variable, multiple genes are mutated with no unifying mechanism, and essential regulatory pathways and surrounding microenvironments are diverse. We sought to clarify the heterogeneity of SMZL by resolving different subgroups and their underlying genomic abnormalities, pathway signatures, and microenvironment compositions to uncover biomarkers and therapeutic vulnerabilities. We studied 303 SMZL spleen samples collected through the IELSG46 multicenter international study (NCT02945319) by using a multiplatform approach. We carried out genetic and phenotypic analyses, defined self-organized signatures, validated the findings in independent primary tumor metadata and in genetically modified mouse models, and determined correlations with outcome data. We identified 2 prominent genetic clusters in SMZL, termed NNK (58% of cases, harboring NF-κB, NOTCH, and KLF2 modules) and DMT (32% of cases, with DNA-damage response, MAPK, and TLR modules). Genetic aberrations in multiple genes as well as cytogenetic and immunogenetic features distinguished NNK- from DMT-SMZLs. These genetic clusters not only have distinct underpinning biology, as judged by differences in gene-expression signatures, but also different outcomes, with inferior survival in NNK-SMZLs. Digital cytometry and in situ profiling segregated 2 basic types of SMZL immune microenvironments termed immune-suppressive SMZL (50% of cases, associated with inflammatory cells and immune checkpoint activation) and immune-silent SMZL (50% of cases, associated with an immune-excluded phenotype) with distinct mutational and clinical connotations. In summary, we propose a nosology of SMZL that can implement its classification and also aid in the development of rationally targeted treatments.

Polatuzumab vedotin (Pola) + rituximab (R) + lenalidomide (Len) in patients (pts) with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL): Primary analysis of a phase 1b/2 trial

7512

Background: The combination of Pola-R-Len may enhance anti-tumor response in R/R DLBCL. We report the primary analysis of the R/R DLBCL cohort in a Phase 1b/2 study (GO29834; NCT02600897). Methods: Pts received induction with 6 x 28-Day (D) cycles (C) of: Pola 1.8mg/kg intravenous (IV; C1−6: D1); R 375mg/m2 IV (C1−6: D1) and oral Len 10–20mg (dose escalation) or recommended Phase 2 dose (RP2D) daily on D1–21. Pts with a response at end of induction (EOI) received 6 months (mo) consolidation with R 375mg/m2 (D1 every 2 mo) and Len 10mg (D1–21 monthly). Primary endpoints were safety/tolerability and positron emission tomography (PET)-complete response (CR) rate at EOI by independent review committee (IRC) by modified Lugano criteria. Results: At primary analysis (Sep 08, 2020), 57 pts were enrolled. Median age was 71 years (range 28–92); male (67%); Ann Arbor Stage III–IV (86%); International Prognostic Index 3–5 (60%); median 2 prior therapies; prior bone marrow transplant (11%); prior CAR-T therapy (5%); primary refractory (49%) and refractory to last therapy (65%). Grade 3–4 adverse events (AEs) were experienced by 75% of pts, most commonly, neutropenia (58%), thrombocytopenia (14%), infections (14%) and anemia (11%). AEs led to Len dose reduction in 25% and interruption in 63% of pts. One Grade 5 treatment-related AE (neutropenic sepsis) was reported. In total, 49 pts were treated at RP2D (Pola 1.8mg/kg + Len 20mg). IRC PET-CR rate at EOI was 29% (Table). A best overall response (BOR) assessed by investigator (INV) was seen in 36/49 (74%) pts with 17/49 (35%) pts achieving a CR; of these, 14/17 (82%) remain in remission at the cutoff date. Median duration of response (DOR) was 8.1 mo (95% confidence interval [CI]: 4.7–not evaluable [NE]). After a median follow-up of 9.7 mo, median progression-free survival (PFS) and overall survival (OS) were 6.3 mo (95% CI: 4.5–9.7) and 10.9 mo (95% CI: 7.4–NE), respectively. Conclusions: Our study of the novel triplet combination, Pola-R-Len, demonstrates a tolerable safety profile. This first efficacy report of Pola-R-Len shows promising activity in a difficult-to-treat R/R DLBCL population, particularly in pts achieving CR, a large proportion of whom remain in remission at the cutoff date. Further evaluation of Pola-R-Len and the impact of consolidation therapy is warranted to address the significant unmet need in this patient population. Clinical trial information: NCT02600897. [Table: see text]

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1-3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10-18.

Clinicopathological evaluation of the programmed cell death 1 (PD1)/programmed cell death-ligand 1 (PD-L1) axis in post-transplant lymphoproliferative disorders: association with Epstein-Barr virus, PD-L1 copy number alterations, and outcome

AIMS

The clinical implications of the programmed cell death 1 (PD1)/programmed cell death-ligand 1 (PD-L1) axis in patients with post-transplant lymphoproliferative disorders are largely unknown, and its association with Epstein-Barr virus (EBV) status and PD-L1 copy number alterations (CNAs) has not been thoroughly studied.

METHODS AND RESULTS

PD1/PD-L1 expression was studied in 50 adult post-transplant lymphoproliferative disorders, and the correlations with PD-L1 CNAs, EBV, clinicopathological features and outcome were evaluated. Thirty-seven (74%) cases were classified as diffuse large B-cell lymphoma (DLBCL), nine (18%) cases were classified as polymorphic, and four (8%) cases were classified as classic Hodgkin lymphoma. Thirty-four cases were EBV-positive, with 29 of 34 (85%) having latency II or III, and 15 of 34 (44%) having viral replication. PD-L1 expression in tumour cells and tumour-associated macrophages was observed in 30 (60%) and 37 (74%) cases, respectively. PD1 positivity was seen in 16 (32%) cases. PD-L1 expression was associated with EBV with latency II or III (P = 0.001) and organ rejection (P = 0.04), and, in DLBCL, with non-germinal centre type DLBCL (P < 0.001). Cases with PD-L1-positive tumour cells showed a higher number of PD-L1 CNAs than PD-L1-negative cases (P = 0.001). Patients with EBV/latency III/replication and simultaneous PD-L1 expression showed the worst overall survival (P < 0.001).

CONCLUSIONS

The PD1/PD-L1 axis is deregulated in post-transplant lymphoproliferative disorders, with frequent PD-L1 expression and PD1 negativity. PD-L1 expression is associated with EBV latency II or III and PD-L1 CNAs, and probably reflects a proinflammatory tumour microenvironment. The combined analysis of EBV status and PD-L1 expression may help to identify deeply immunosuppressed patients who can benefit from immune reconstitution approaches.

Early progression of disease (POD24) as survival predictor in MALT lymphoma

7548

Background: Progression of disease within two years from start of therapy (POD24) is linked with poor outcome in follicular lymphoma. It is less clear whether POD24 affects overall survival (OS) also in extranodal marginal zone B-cell lymphoma of mucosa associated lymphoid tissue (MALT lymphoma). Methods: We analyzed the dataset of the IELSG19 clinical trial (training set) to determine whether POD24 is associated with inferior OS. The study population included 401 EMZL patients (131 randomly assigned to chlorambucil treatment, 138 to rituximab and 132 to chlorambucil plus rituximab). Reproducibility was analyzed in an independent cohort (validation set) of 218 patients who received systemic treatment (chemotherapy, immunotherapy or both). In both, training and validation sets, we excluded from the analysis the patients who, within 24 months from treatment start, died without progression or were lost to follow-up without progression. Overall survival (OS) was calculated from disease progression in patients with POD24 and from 24 months after start of treatment in those without POD24 (reference group). Results: POD24 was observed in 69 of 401 patients of the IELSG19 study and 58 of 218 patients in the validation cohort. In the training set, the 10-year OS rates were 64% in the POD24 group and 85% in the reference group (HR = 2.42, 95%CI, 1.35-4.34; log-rank P = 0.002) and POD24 predicted poor outcome regardless of treatment type (multivariable Cox model, P = 0.003). The prognostic impact of POD24 was confirmed in the validation set, with 10-year OS rates of 48% in the POD24 group and 71% in the reference group (HR = 2.17, 95%CI, 1.20-3.93; log-rank P = 0.009). Conclusions: In patients with EMZL who received front-line systemic treatment, POD24 is associated with poorer survival and may represent a useful endpoint in future prospective clinical trial.

High TNFRSF14 and low BTLA are associated with poor prognosis in Follicular Lymphoma and in Diffuse Large B-cell Lymphoma transformation

The microenvironment influences the behavior of follicular lymphoma (FL) but the specific roles of the immunomodulatory BTLA and TNFRSF14 (HVEM) are unknown. Therefore, we examined their immunohistochemical expression in the intrafollicular, interfollicular and total histological compartments in 106 FL cases (57M/49F; median age 57-years), and in nine relapsed-FL with transformation to DLBCL (tFL). BTLA expression pattern was of follicular T-helper cells (TFH) in the intrafollicular and of T-cells in the interfollicular compartments. The mantle zones were BTLA+ in 35.6% of the cases with similar distribution of IgD. TNFRSF14 expression pattern was of neoplastic B lymphocytes (centroblasts) and “tingible body macrophages”. At diagnosis, the averages of total BTLA and TNFRSF14-positive cells were 19.2%±12.4STD (range, 0.6%-58.2%) and 46.7 cells/HPF (1-286.5), respectively. No differences were seen between low-grade vs. high-grade FL but tFL was characterized by low BTLA and high TNFRSF14 expression. High BTLA correlated with good overall survival (OS) (total-BTLA, Hazard Risk=0.479, P=0.022) and with high PD-1 and FOXP3+Tregs. High TNFRSF14 correlated with poor OS and progression-free survival (PFS) (total-TNFRSF14, HR=3.9 and 3.2, respectively, P<0.0001), with unfavorable clinical variables and higher risk of transformation (OR=5.3). Multivariate analysis including BTLA, TNFRSF14 and FLIPI showed that TNFRSF14 and FLIPI maintained prognostic value for OS and TNFRSF14 for PFS. In the GSE16131 FL series, high TNFRSF14 gene expression correlated with worse prognosis and GSEA showed that NFkB pathway was associated with the “High-TNFRSF14/dead-phenotype”.

In conclusion, the BTLA-TNFRSF14 immune modulation pathway seems to play a role in the pathobiology and prognosis of FL.

Mutations in the RAS-BRAF-MAPK-ERK pathway define a specific subgroup of patients with adverse clinical features and provide new therapeutic options in chronic lymphocytic leukemia

Mutations in genes of the RAS-BRAF-MAPK-ERK pathway have not been fully explored in patients with chronic lymphocytic leukemia. We, therefore, analyzed the clinical and biological characteristics of chronic lymphocytic leukemia patients with mutations in this pathway and investigated the in vitro response of primary cells to BRAF and ERK inhibitors. Putative damaging mutations were found in 25 of 452 patients (5.5%). Among these, BRAF was mutated in nine patients (2.0%), genes upstream of BRAF (KITLG, KIT, PTPN11, GNB1, KRAS and NRAS) were mutated in 12 patients (2.6%), and genes downstream of BRAF (MAPK2K1, MAPK2K2, and MAPK1) were mutated in five patients (1.1%). The most frequent mutations were missense, subclonal and mutually exclusive. Patients with these mutations more frequently had increased lactate dehydrogenase levels, high expression of ZAP-70, CD49d, CD38, trisomy 12 and unmutated immunoglobulin heavy-chain variable region genes and had a worse 5-year time to first treatment (hazard ratio 1.8, P=0.025). Gene expression analysis showed upregulation of genes of the MAPK pathway in the group carrying RAS-BRAF-MAPK-ERK pathway mutations. The BRAF inhibitors vemurafenib and dabrafenib were not able to inhibit phosphorylation of ERK, the downstream effector of the pathway, in primary cells. In contrast, ulixertinib, a pan-ERK inhibitor, decreased phospho-ERK levels. In conclusion, although larger series of patients are needed to corroborate these findings, our results suggest that the RAS-BRAF-MAPK-ERK pathway is one of the core cellular processes affected by novel mutations in chronic lymphocytic leukemia, is associated with adverse clinical features and could be pharmacologically inhibited.

Genetics and Pathogenesis of Diffuse Large B-Cell Lymphoma

BACKGROUND

Diffuse large B-cell lymphomas (DLBCLs) are phenotypically and genetically heterogeneous. Gene-expression profiling has identified subgroups of DLBCL (activated B-cell-like [ABC], germinal-center B-cell-like [GCB], and unclassified) according to cell of origin that are associated with a differential response to chemotherapy and targeted agents. We sought to extend these findings by identifying genetic subtypes of DLBCL based on shared genomic abnormalities and to uncover therapeutic vulnerabilities based on tumor genetics.

METHODS

We studied 574 DLBCL biopsy samples using exome and transcriptome sequencing, array-based DNA copy-number analysis, and targeted amplicon resequencing of 372 genes to identify genes with recurrent aberrations. We developed and implemented an algorithm to discover genetic subtypes based on the co-occurrence of genetic alterations.

RESULTS

We identified four prominent genetic subtypes in DLBCL, termed MCD (based on the co-occurrence of MYD88L265P and CD79B mutations), BN2 (based on BCL6 fusions and NOTCH2 mutations), N1 (based on NOTCH1 mutations), and EZB (based on EZH2 mutations and BCL2 translocations). Genetic aberrations in multiple genes distinguished each genetic subtype from other DLBCLs. These subtypes differed phenotypically, as judged by differences in gene-expression signatures and responses to immunochemotherapy, with favorable survival in the BN2 and EZB subtypes and inferior outcomes in the MCD and N1 subtypes. Analysis of genetic pathways suggested that MCD and BN2 DLBCLs rely on "chronic active" B-cell receptor signaling that is amenable to therapeutic inhibition.

CONCLUSIONS

We uncovered genetic subtypes of DLBCL with distinct genotypic, epigenetic, and clinical characteristics, providing a potential nosology for precision-medicine strategies in DLBCL. (Funded by the Intramural Research Program of the National Institutes of Health and others.).

The BET bromodomain inhibitor CPI203 overcomes resistance to ABT-199 (venetoclax) by downregulation of BFL-1/A1 in in vitro and in vivo models of MYC+/BCL2+ double hit lymphoma

High-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements, mostly known as double-hit lymphoma (DHL), is a rare entity characterized by morphologic and molecular features between Burkitt lymphoma and the clinically manageable diffuse large B-cell lymphoma (DLBCL). DHL patients usually undergo a rapidly progressing clinical course associated with resistance to standard chemo-immunotherapy. As a consequence, the prognosis of this entity is particularly poor with a median overall survival inferior to 1 year. ABT-199 (venetoclax) is a potent and selective small-molecule antagonist of BCL-2 recently approved for the treatment of a specific subtype of lymphoid neoplasm. In this study, we demonstrate that single-agent ABT-199 efficiently displaces BAX from BCL-2 complexes but fails to maintain a significant antitumor activity over time in most MYC+/BCL2+DHL cell lines and primary cultures, as well as in a xenograft mouse model of the disease. We further identify the accumulation of the BCL2-like protein BFL-1 to be a major mechanism involved in acquired resistance to ABT-199. Noteworthy, this phenomenon can be counteracted by the BET bromodomain inhibitor CPI203, since gene expression profiling identifies BCL2A1, the BFL-1 coding gene, as one of the top apoptosis-related gene modulated by this compound. Upon CPI203 treatment, simultaneous downregulation of MYC and BFL-1 further overcomes resistance to ABT-199 both in vitro and in vivo, engaging synergistic caspase-mediated apoptosis in DHL cultures and tumor xenografts. Together, these findings highlight the relevance of BFL-1 in DH lymphoma-associated drug resistance and support the combined use of a BCL-2 antagonist and a BET inhibitor as a promising therapeutic strategy for patients with aggressive DHL.

Phase 1b/3 study of avelumab-based combination regimens in patients with relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL)

TPS7575

Background: Approximately 50% of patients (pts) with advanced DLBCL are refractory to or relapse following first line R-CHOP therapy. Pts with R/R DLBCL have limited treatment options and a poor prognosis. This study assesses immunotherapy-based regimens containing avelumab (a fully human IgG1 anti–PD-L1 antibody) in combination with utomilumab (a novel 4-1BB agonist), azacitidine, rituximab, and/or conventional chemotherapy (CT; bendamustine) in pts with R/R DLBCL. Methods: JAVELIN DLBCL (NCT02951156) is a global, multicenter, randomized, open-label, 2-component(phase 1b followed by phase 3) study of avelumab-based combination regimens in R/R DLBCL. In phase 1b, up to 84 pts will be randomized 1:1:1 to receive avelumab/rituximab/utomilumab, or avelumab/azacitidine/utomilumab, or avelumab/rituximab/bendamustine. The primary phase 1b objectives are preliminary assessments of dose-limiting toxicities (n = 6 per arm) and efficacy (objective response [OR]; n = 28 per arm). One regimen from phase 1b will be selected for phase 3 evaluation in 220 additional pts randomized 1:1 to the chosen regimen or investigator’s choice CT (rituximab/bendamustine or rituximab/gemcitabine/oxaliplatin). The primary phase 3 objective is to demonstrate progression-free survival (PFS) superiority of the avelumab-based regimen over CT. Overall survival is a key secondary endpoint. Eligible pts have completed up to 4 lines of prior rituximab/multiagent CT, and/or have failed autologous stem cell transplantation (ASCT), or are not eligible for intensive CT or ASCT. Other eligibility criteria include ECOG PS ≤1 and no prior therapy with a checkpoint inhibitor. Treatment with avelumab, utomilumab, and azacitidine will be continued until the pt no longer receives clinical benefit; rituximab and bendamustine are limited to 8 and 6 cycles, respectively. OR and PFS will be assessed per Lugano disease classification criteria. Other secondary efficacy endpoints include disease control, duration of response, time to response, and minimal residual disease burden. Safety, PK, immunogenicity, pt-reported outcomes, and biomarkers will also be evaluated. Clinical trial information: NCT02951156.

Lenalidomide Maintenance Compared With Placebo in Responding Elderly Patients With Diffuse Large B-Cell Lymphoma Treated With First-Line Rituximab Plus Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone

Purpose The standard treatment of patients with diffuse large B-cell lymphoma (DLBCL) is rituximab in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Lenalidomide, an immunomodulatory agent, has shown activity in DLBCL. This randomized phase III trial compared lenalidomide as maintenance therapy with placebo in elderly patients with DLBCL who achieved a complete response (CR) or partial response (PR) to R-CHOP induction. Methods Patients with previously untreated DLBCL or other aggressive B-cell lymphoma were 60 to 80 years old, had CR or PR after six or eight cycles of R-CHOP, and were randomly assigned to lenalidomide maintenance 25 mg/d or placebo for 21 days of every 28-day cycle for 24 months. The primary end point was progression-free survival (PFS). Results A total of 650 patients were randomly assigned. At the time of the primary analysis (December 2015), with a median follow-up of 39 months from random assignment, median PFS was not reached for lenalidomide maintenance versus 58.9 months for placebo (hazard ratio, 0.708; 95% CI, 0.537 to 0.933; P = .01). The result was consistent among analyzed subgroups (eg, male v female, age-adjusted International Prognostic Index 0 or 1 v 2 or 3, age younger than 70 v ≥ 70 years), response (PR v CR) after R-CHOP, and positron emission tomography status at assignment (negative v positive). With longer median follow-up of 52 months (October 2016), overall survival was similar between arms (hazard ratio, 1.218; 95% CI, 0.861 to 1.721; P = .26). Most common grade 3 or 4 adverse events associated with lenalidomide versus placebo maintenance were neutropenia (56% v 22%) and cutaneous reactions (5% v 1%), respectively. Conclusion Lenalidomide maintenance for 24 months after obtaining a CR or PR to R-CHOP significantly prolonged PFS in elderly patients with DLBCL.

Validation of the NCCN-IPI for diffuse large B-cell lymphoma (DLBCL): the addition of β2 -microglobulin yields a more accurate GELTAMO-IPI

The study included 1848 diffuse large B-cell lymphoma (DLBCL)patients treated with chemotherapy/rituximab. The aims were to validate the National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) and explore the effect of adding high Beta-2 microglobulin (β2M), primary extranodal presentation and intense treatment to the NCCN-IPI variables in order to develop an improved index. Comparing survival curves, NCCN-IPI discriminated better than IPI, separating four risk groups with 5-year overall survival rates of 93%, 83%, 67% and 49%, but failing to identify a true high-risk population. For the second aim the series was split into training and validation cohorts: in the former the multivariate model identified age, lactate dehydrogenase, Eastern Cooperative Oncology Group performance status, Stage III-IV, and β2M as independently significant, whereas the NCCN-IPI-selected extranodal sites, primary extranodal presentation and intense treatments were not. These results were confirmed in the validation cohort. The Grupo Español de Linfomas/Trasplante de Médula ósea (GELTAMO)-IPI developed here, with 7 points, significantly separated four risk groups (0, 1-3, 4 or ≥5 points) with 11%, 58%, 17% and 14% of patients, and 5-year overall survival rates of 93%, 79%, 66% and 39%, respectively. In the comparison GELTAMO IPI discriminated better than the NCCN-IPI. In conclusion, GELTAMO-IPI is more accurate than the NCCN-IPI and has statistical and practical advantages in that the better discrimination identifies an authentic high-risk group and is not influenced by primary extranodal presentation or treatments of different intensity.

Frequent NFKBIE deletions are associated with poor outcome in primary mediastinal B-cell lymphoma

We recently reported a truncating deletion in the NFKBIE gene, which encodes IκBε, a negative feedback regulator of NF-κB, in clinically aggressive chronic lymphocytic leukemia (CLL). Because preliminary data indicate enrichment of NFKBIE aberrations in other lymphoid malignancies, we screened a large patient cohort (n = 1460) diagnosed with different lymphoid neoplasms. While NFKBIE deletions were infrequent in follicular lymphoma, splenic marginal zone lymphoma, and T-cell acute lymphoblastic leukemia (<2%), slightly higher frequencies were seen in diffuse large B-cell lymphoma, mantle cell lymphoma, and primary central nervous system lymphoma (3% to 4%). In contrast, a remarkably high frequency of NFKBIE aberrations (46/203 cases [22.7%]) was observed in primary mediastinal B-cell lymphoma (PMBL) and Hodgkin lymphoma (3/11 cases [27.3%]). NFKBIE-deleted PMBL patients were more often therapy refractory (P = .022) and displayed inferior outcome compared with wild-type patients (5-year survival, 59% vs 78%; P = .034); however, they appeared to benefit from radiotherapy (P =022) and rituximab-containing regimens (P = .074). NFKBIE aberrations remained an independent factor in multivariate analysis (P = .003) and when restricting the analysis to immunochemotherapy-treated patients (P = .008). Whole-exome sequencing and gene expression profiling verified the importance of NF-κB deregulation in PMBL. In summary, we identify NFKBIE aberrations as a common genetic event across B-cell malignancies and highlight NFKBIE deletions as a novel poor-prognostic marker in PMBL.

Decoding the DNA Methylome of Mantle Cell Lymphoma in the Light of the Entire B Cell Lineage

We analyzed the in silico purified DNA methylation signatures of 82 mantle cell lymphomas (MCL) in comparison with cell subpopulations spanning the entire B cell lineage. We identified two MCL subgroups, respectively carrying epigenetic imprints of germinal-center-inexperienced and germinal-center-experienced B cells, and we found that DNA methylation profiles during lymphomagenesis are largely influenced by the methylation dynamics in normal B cells. An integrative epigenomic approach revealed 10,504 differentially methylated regions in regulatory elements marked by H3K27ac in MCL primary cases, including a distant enhancer showing de novo looping to the MCL oncogene SOX11. Finally, we observed that the magnitude of DNA methylation changes per case is highly variable and serves as an independent prognostic factor for MCL outcome.

Transposon Mutagenesis Reveals Fludarabine Resistance Mechanisms in Chronic Lymphocytic Leukemia

PURPOSE

To identify resistance mechanisms for the chemotherapeutic drug fludarabine in chronic lymphocytic leukemia (CLL), as innate and acquired resistance to fludarabine-based chemotherapy represents a major challenge for long-term disease control.

EXPERIMENTAL DESIGN

We used piggyBac transposon-mediated mutagenesis, combined with next-generation sequencing, to identify genes that confer resistance to fludarabine in a human CLL cell line.

RESULTS

In total, this screen identified 782 genes with transposon integrations in fludarabine-resistant pools of cells. One of the identified genes is a known resistance mediator DCK (deoxycytidine kinase), which encodes an enzyme that is essential for the phosphorylation of the prodrug to the active metabolite. BMP2K, a gene not previously linked to CLL, was also identified as a modulator of response to fludarabine. In addition, 10 of 782 transposon-targeted genes had previously been implicated in treatment resistance based on somatic mutations seen in patients refractory to fludarabine-based therapy. Functional characterization of these genes supported a significant role for ARID5B and BRAF in fludarabine sensitivity. Finally, pathway analysis of transposon-targeted genes and RNA-seq profiling of fludarabine-resistant cells suggested deregulated MAPK signaling as involved in mediating drug resistance in CLL.

CONCLUSIONS

To our knowledge, this is the first forward genetic screen for chemotherapy resistance in CLL. The screen pinpointed novel genes and pathways involved in fludarabine resistance along with previously known resistance mechanisms. Transposon screens can therefore aid interpretation of cancer genome sequencing data in the identification of genes modifying sensitivity to chemotherapy. Clin Cancer Res; 22(24); 6217-27. ©2016 AACR.

In vivo intratumoral Epstein-Barr virus replication is associated with XBP1 activation and early-onset post-transplant lymphoproliferative disorders with prognostic implications

Post-transplant lymphoproliferative disorders are life-threatening complications following hematopoietic or solid organ transplantation. They represent a spectrum of mostly EBV-driven lymphoplasmacytic proliferations. While the oncogenic effect of EBV is related to latent infection, lytic infection also has a role in lymphomagenesis. In vitro, EBV replication is linked to plasma cell differentiation and XBP1 activation, although this phenomenon has never been addressed in vivo. We analyzed for the first time latent and lytic intratumoral EBV infection in a series of 35 adult patients with a diagnosis of post-transplant lymphoproliferative disorder (26M/9F, median age 54 years). A complete EBV study was performed including the analysis of the latent EBER, latent membrane protein-11, and EBV nuclear antigens as well as the immediate-early BZLF1/ZEBRA and early BMRF1/EADE31 lytic genes. XBP1 activation was assessed by nuclear protein expression. EBV infection was observed in 28 (80%) cases being latency II and III the most frequently observed 22 (79%). Intratumoral EBV replication was detected in 17 (60%) cases. Among these, XBP1 activation was observed in 11/12 evaluable cases associated with strong cytoplasmic immunoglobulin expression consistent with plasma cell differentiation. Intriguingly, the combination of latency III infection and EBV replication identified a high-risk subgroup of patients with significantly shorter survival (overall survival at 1 year 18% vs 48%) and early-onset (median of 7 vs 26 months) post-transplant lymphoproliferative disorder. Moreover, these patients appear to be more heavily immunosuppressed, so they exhibit lower rates of rejection and graft vs host disease but higher rates of cytomegalovirus reactivation. In conclusion, EBV replication is associated with plasma cell differentiation and XBP1 activation with prognostic implications. Both latency III and lytic EBV infection are related to aggressive and early-onset post-transplant lymphoproliferative disorder. These results suggest that immunohistochemical study of latent and lytic EBV genes in the clinical practice may help to select higher-risk patients to new therapies including antiviral treatments.

[18F]fluorodeoxyglucose positron emission tomography predicts survival after chemoimmunotherapy for primary mediastinal large B-cell lymphoma: results of the International Extranodal Lymphoma Study Group IELSG-26 Study

PURPOSE

To assess the role of [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) after rituximab and anthracycline-containing chemoimmunotherapy in patients with primary mediastinal large B-cell lymphoma (PMLBCL).

PATIENTS AND METHODS

Among 125 patients prospectively enrolled, 115 were eligible for central review of PET/CT scans at the completion of standard chemoimmunotherapy, by using a five-point scale. Consolidation radiotherapy (RT) was permitted and given to 102 patients.

RESULTS

Fifty-four patients (47%) achieved a complete metabolic response (CMR), defined as a completely negative scan or with residual [18F]FDG activity below the mediastinal blood pool (MBP) uptake. In the remaining 61 patients (53%), the residual uptake was higher than MBP uptake but below the liver uptake in 27 (23%), slightly higher than the liver uptake in 24 (21%), and markedly higher in 10 (9%). CMR after chemoimmunotherapy predicted higher 5-year progression-free survival (PFS; 98% v 82%; P=.0044) and overall survival (OS; 100% v 91%; P=.0298). Patients with residual uptake higher than MBP uptake but below liver uptake had equally good outcomes without any recurrence. Using the liver uptake as cutoff for PET positivity (boundary of score, 3 to 4) discriminated most effectively between high or low risk of failure, with 5-year PFS of 99% versus 68% (P<.001) and 5-year OS of 100% versus 83% (P<.001).

CONCLUSION

More than 90% of patients are projected to be alive and progression-free at 5 years, despite a low CMR rate (47%) after chemoimmunotherapy. This study provides a basis for using PET/CT to define the role of RT in PMLBCL.

Primary brain lymphomas after kidney transplantation: an under-recognized problem?

Primary central nervous system post-transplant lymphoproliferative disease (CNS PTLD) is a serious complication after solid organ transplantation that has not received much attention so far. However, it could become a more frequent problem with the introduction of new biological agents.

METHODS

We identified five cases with CNS PTLD in our center who were transplanted between 1986 and 2007, three men and two women, with a mean age of 55.9 years (range 42-74). Three patients had received only kidney transplant and two patients had received a kidney-pancreas transplant.

RESULTS

The mean time from first symptoms until diagnosis was 3.5 months (2-6). One patient was diagnosed post-mortem in autopsy. The mean time from transplantation to onset of neurological symptoms was 73.8 months (31-144). The initial clinical manifestation was heterogeneous: all five cases showed headache, four cases presented with gait disturbance, one with dysarthria and two with a confusional state. Epstein-Barr virus (EBV) immunoglobulin (Ig)G serology was positive in four out of five cases; in situ hybridization for EBV in brain biopsy samples was positive in three cases, negative in one and not available in one. In four patients, EBV polymerase chain reaction (PCR) was positive in cerebrospinal fluid (CSF). After diagnosis, overall immunosuppressive load was lowered in all patients (n = 4). Three patients died at 8-104 weeks (mean 40 weeks) after diagnosis and one patient is still alive 20 months after diagnosis.

CONCLUSIONS

CNS PTLD is a complication difficult to diagnose, frequently diagnosed too late and often refractory to treatment. A more aggressive screening might be necessary in patients even with mild CNS symptoms.

Peripheral blood involvement in patients with follicular lymphoma: a rare disease manifestation associated with poor prognosis

Follicular Lymphoma (FL) is the second most common non-Hodgkin lymphoma (NHL) subtype and its course is heterogeneous. At diagnosis, some patients with FL manifest a detectable leukaemic phase (FL-LP), but this feature has been seldom described and is poorly characterized. Among 499 patients diagnosed with FL in Lyon-Sud hospital, 37 (7·4%) had characteristic FL-LP (by cytological blood smears and flow cytometric analysis). In addition, 91/1135 FL patients from the PRIMA study presented FL-LP at study entry. In order to evaluate the outcome of this Lyon-Sud cohort, FL-LP patients were matched with 111 newly diagnosed FL without LP according to the Follicular Lymphoma International Prognostic Index (FLIPI) score, age and treatment. Presence of FL-LP was associated with shorter progression-free survival (PFS) and overall survival (OS) (P = 0·004 and P = 0·031, respectively). Presence of FL-LP and high FLIPI score remained independent prognostic factors in a Cox model for time to progression (TTP). A number of circulating lymphoma cells (CLC) >4 × 10(9) /l was the most significant predictor for a shorter TTP in this Cox model. The prognostic impact of FL-LP on TTP was validated in the PRIMA cohort (P = 0·0004). In conclusion, FL-LP is a rare event associated with shorter PFS and patients with CLC >4 × 10(9) /l have a poorer outcome. These patients should be monitored carefully to consider alternative therapeutic options.

A randomized study of interferon α-2b versus no treatment as consolidation after high dose therapy and autologous stem cell transplantation for patients with relapsed lymphoma

Patients with lymphoma who have experienced a first relapse or progression and have disease deemed sensitive to salvage chemotherapy nevertheless have a high likelihood of having a second relapse. To decrease the likelihood of a second relapse after high-dose therapy (HDT) and autologous stem cell transplantation (ASCT), interferon (IFN) α-2b was given in a prospective randomized international trial. Methods. In this trial, 221 patients with varying histologic diagnoses (8 small lymphocytic, 37 follicular, 9 mantle, 90 diffuse large B-cell, 20 peripheral T-cell, 3 high-grade B-cell non-Hodgkin lymphoma, and 54 Hodgkin lymphoma) were randomly assigned to receive no further treatment (arm A: 117 patients) or IFNα-2b, 3 MU three times weekly, for 18 months (arm B: 104 patients). Results. In arm B, 21 patients (20%) did not receive IFNα-2b because of early progression or absence of hematologic recovery, 29 patients (28%) completed the 18 months of treatment, and 54 patients (52%) interrupted treatment because of progression (23%) or toxicity (29%). Event-free survival and overall survival were not different between the two arms on an intent-to-treat analysis and also if analysis was restricted to patients who were alive and had not experienced disease progression three months after transplantation. The study was not sufficiently powered to evaluate effects in histologic subtypes. Conclusion. In this trial, post-autograft IFNα-2b did not improve outcomes in a heterogeneous group of patients with lymphoma.

Abstract 993: Upregulation of B-cell activation genes and negative regulators of apoptosis determines resistance to bendamustine in chronic lymphocytic leukemia cells

Chronic lymphocytic leukemia (CLL), the most common leukemia in Western countries, is characterized by the accumulation of monoclonal CD5+ B cells in the blood, bone marrow, lymph nodes, spleen and other lymphoid organs. Bendamustine hydrochloride, a cytotoxic agent comprising structural features of both an alkylating drug and a purine nucleoside analog, was recently approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the treatment of CLL and indolent B cell non-Hodgkin's lymphoma (NHL). Although several recent clinical trials have documented the activity of bendamustine in CLL, the mechanisms of bendamustine resistance in CLL cells have not been yet elucidated.

We analyzed the ex vivo cytotoxicity of bendamustine in cells from 48 CLL cases by incubating them with bendamustine 25 μM for 24 hours. Cell death was assessed by annexinV-PI labeling and cases were classified as bendamustine-resistant (cytotoxicity below 30%) or bendamustine-sensitive (cytotoxicity over 30%) cases. We found that sensitivity of CLL primary cells correlated with the mutational status of IGHV gene, being the IGHV-unmutated cases significantly more resistant to bendamustine (p&lt;0.015) than those cases with mutated IGHV. Although the number of cases analyzed was low, no correlation with the mutational status of NOTCH1 or SF3B1 was observed.

We compared the gene expression profiling of bendamustine-resistant and bendamustine-sensitive groups by performing a high-throughput analysis of basal gene expression in CLL cells with the U219 Affymetrix array. After a supervised analysis using the Rank Products method and a FDR below 0.001, we observed 393 up-regulated genes and 415 down-regulated genes in the bendamustine-resistant group. Annotation of the differentially expressed genes identified some well-known markers of prognosis in CLL, together with genes related to apoptosis regulation and B cell activation. One of the genes with a highest positive fold-change and most relevant according to its role in cell cycle progression, apoptosis and transformation was C-MYC.

These results suggest that overexpression of genes related to proliferation and B-cell activation could be involved in CLL resistance to bendamustine therapy, which is known to be clinically more effective in indolent than in aggressive lymphomas. Further studies will assess whether this set of overexpressed genes might be useful as biomarkers to predict the sensitivity to bendamustine and open the door to new combinatorial strategies that might overcome resistance to bendamustine in CLL patients within the context of tailored medicine

Citation Format: Eriong Lee-Verges, Arnau Montraveta, Magda Pinyol, Pedro Jares, Cristina Arimany-Nardi, Marta Aymerich, Neus Villamor, Marçal Pastor-Anglada, Armando Lopez-Guillermo, Patricia Perez-Galan, Gael Roue, Elias Campo, Dolors Colomer. Upregulation of B-cell activation genes and negative regulators of apoptosis determines resistance to bendamustine in chronic lymphocytic leukemia cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 993. doi:10.1158/1538-7445.AM2013-993

Interim FDG PET/CT as a prognostic factor in diffuse large B-cell lymphoma

PURPOSE

Interim (18)F-FDG PET performed early during the course of therapy in diffuse large B-cell lymphoma (DLBCL) is a good predictor of outcome. However, interpretation criteria for interim PET for the evaluation of tumour response are still not clearly defined. The study aim was to assess whether interim PET can predict overall survival (OS) and progression-free survival (PFS) in DLBCL patients following three different sets of parameters, two qualitative (visual) methods and one semiquantitative.

METHODS

A total of 50 newly diagnosed DLBCL patients were prospectively enrolled in this study. All patients had a PET/CT scan at diagnosis and an interim PET/CT scan after the second or third cycle of chemotherapy. Three methods of evaluation for the interim PET/CT were used: a qualitative three-point scoring (3-PS) method, a qualitative 5-PS method and a semiquantitative method (ΔSUVmax). The degree of correlation between therapy response seen on FDG PET and PFS and OS was determined.

RESULTS

The analysis of the visual 3-PS method showed no statistically significant difference in PFS and OS. The estimated 5-year PFS and OS were 79 % and 92 %, respectively, in patients with an interim PET scan showing uptake not greater than in the liver versus 50 % in patients with uptake greater than in the liver, and this difference was statistically significant. The optimal cut-off value of ΔSUVmax that could predict the PFS and OS difference in patients with DLBCL was 76 % (95 % CI 62.7-89.2 %) and 75 % (95 % CI, 54.6-95.4 %), respectively.

CONCLUSION

Our results support the use of liver uptake as an indicator in the qualitative evaluation of interim PET, or a ΔSUVmax greater than 75 % in semiquantitative analysis. Interim PET may predict PFS and OS and could be considered in the prognostic evaluation of DLBCL.

Retreatment with purine analogs in patients with chronic lymphocytic leukemia

We evaluated the efficacy and toxicity of retreatment with purine analogs (PA) in 62 patients with relapsed chronic lymphocytic leukemia. Median OS and PFS after retreatment were 60 and 26 months, respectively. By multivariate analysis, minimal residual disease status, ZAP-70 expression and age had independent predictive power in terms of OS. Toxicity was mainly neutropenia (21%) and infections (39%). Second malignancies were observed in 10 (16%) patients. Our results outline that retreatment with PA is remarkably effective in patients with relapsed CLL, but with a significant toxicity.

Molecular subsets of mantle cell lymphoma defined by the IGHV mutational status and SOX11 expression have distinct biologic and clinical features

Mantle cell lymphoma (MCL) is a heterogeneous disease with most patients following an aggressive clinical course, whereas others having an indolent behavior. We conducted an integrative and multidisciplinary analysis of 177 MCL to determine whether the immunogenetic features of the clonotypic B-cell receptors (BcR) may identify different subsets of tumors. Truly unmutated (100% identity) IGHV genes were found in 24% cases, 40% were minimally/borderline mutated (99.9%-97%), 19% significantly mutated (96.9%-95%), and 17% hypermutated (<95%). Tumors with high or low mutational load used different IGHV genes, and their gene expression profiles were also different for several gene pathways. A gene set enrichment analysis showed that MCL with high and low IGHV mutations were enriched in memory and naive B-cell signatures, respectively. Furthermore, the highly mutated tumors had less genomic complexity, were preferentially SOX11-negative, and showed more frequent nonnodal disease. The best cut-off of germline identity of IGHV genes to predict survival was 97%. Patients with high and low mutational load had significant different outcome with 5-year overall survival (OS) of 59% and 40%, respectively (P = 0.004). Nodal presentation and SOX11 expression also predicted for poor OS. In a multivariate analysis, IGHV gene status and SOX11 expression were independent risk factors. In conclusion, these observations suggest the idea that MCL with mutated IGHV, SOX11-negativity, and nonnodal presentation correspond to a subtype of the disease with more indolent behavior.

Abstract LB-361: The novel PI3K kinase inhibitor NVP-BKM120 shows in vitro and in vivo efficacy in follicular Lymphoma by disrupting microenvironment survival signaling

Follicular lymphoma (FL) is the second most common B- cell non Hodgkin Lymphoma and is characterized by the t(14;18)(q32;q21), leading to over expression of Bcl-2. However, this genetic alteration is not sufficient for tumor development and progression, and it is accepted FL pathogenesis as the result of a functional cross talk between the genetic alterations and the influence of its immune microenvironment in the bone Marrow (BM) and lymph nodes (LN). Although FL is an indolent tumor, up to one-third of cases can progress to a more aggressive disease leading to short survival. The immune microenvironment in the LN plays an important role in tumor development and progression and two outcome-related signatures IR1 and IR2, have been identified by gene expression profiling. IR1, composed of genes expressed by T-cells associated with a more favorable clinical course, and IR2, enriched for genes expressed by macrophages and follicular dendrytic cells (FDC) associated with an inferior clinical course. Recently, PI3K has become an attractive target in cancer therapy. In FL, PI3K/AKT pathway is constitutive activated as a consequence of survival signals coming from tumor microenvironment through cytokine/chemokine secretion (IL4/IL4R, CXCR4/CXCL12) and ligand-receptor interactions that include B-cell receptor (BCR) and CD40/CD40L.Thus, we have evaluated the potential interest of the novel and specific PI3K inhibitor NVP-BKM120 (Novartis) as a new therapy in FL. We found that NVP-BKM120 induces variable cytotoxic and cytostatic effect in FL cell lines, and limited toxicity in FL primary samples (10-20%) in accordance with results with other specific PI3K inhibitors in different models. NVP-BKM120 efficiently blocks constitutive activation of PI3K/AKT pathway in FL cells, and completely abrogates AKT activation derived from co-culture with BM stromal cells or FDCs or consequent to BCR ligation. NVP-BKM120 interferes with tumor cell-microenvironment interactions by blocking SDF1α/CXCL12-induced migration and significantly reduces the secretion of several cytokines (p&lt;0.01), including GM-CSF, G-CSF, CCL2, CCL7, CCL8, IL1, IL7, IL8 and IL10 in a FL-FDC co-culture model. Finally, we have evaluated the in vivo efficacy of this compound in a xenograft mouse model (subcutaneous injection of the FL cell line RL), and NVP-BKM120 reduced tumor size by 35%. Immunohistochemistry analysis revealed a marked decreased in the expression of pAKT and its downstream target pS6rp in tumors from NVP-120-treated mice. These results warrant further studies of NVP-BKM120 in FL. We are now trying to increase its therapeutic index by combination with the BH3-mimetic ABT-263 which is able to antagonize the over expression of Bcl-2, not affected by NVP-BKM120 action, or anti-CD20 antibodies, commonly present in FL current regimens.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-361. doi:1538-7445.AM2012-LB-361

Hepatitis C virus and GBV-C virus prevalence among patients with B-cell lymphoma in different European regions: a case-control study of the International Extranodal Lymphoma Study Group

Hepatitis C virus (HCV) infection is associated with some B-cell non-Hodgkin lymphoma (B cell-NHLs). Patients with HCV infection frequently show co-infections with GB virus C (GBV-C, formerly known as hepatitis G virus), and some studies have suggested a higher incidence of GBV-C infection in patients with B cell-NHLs. The aim of this study was to prospectively evaluate the association between HCV and/or GBV-C infection and B cell-NHLs in different geographic areas. One hundred thirty-seven lymphoma cases and 125 non-lymphoma matched controls were enrolled in an international case-control study conducted in Switzerland (Bellinzona), Spain (Barcelona) and England (Southampton) on samples collected from 2001 to 2002. In Bellinzona (41 cases and 81 controls), the overall prevalence of HCV was 3.3% (4.9% in NHLs), and the overall prevalence of GBV-C was 24% (22% in NHLs). In Barcelona (46 cases and 44 controls), the prevalence of HCV was 10% (8.7% in NHLs) and the prevalence of GBV-C 20% (13% in NHLs). There was no statistically significant difference in the frequency of both infections between patients with NHL and controls. In Southampton, 50 NHL cases were analysed, none of them was found to be HCV-positive; therefore, no control group was analysed and GBV-C analysis was not performed, too. Both in Bellinzona and in Barcelona, the seropositivity rate was significantly lower for HCV than for GBV-C, suggesting that their transmission can be independent. The incidence of HCV was significantly higher in Barcelona than that in Bellinzona. This study confirmed the existence of marked geographic differences in the prevalence of HCV in NHL but cannot provide any significant evidence for an association between HCV and/or GBV-C and B-cell NHLs.

First-Line Treatment for Primary Testicular Diffuse Large B-Cell Lymphoma With Rituximab-CHOP, CNS Prophylaxis, and Contralateral Testis Irradiation: Final Results of an International Phase II Trial

Purpose

Primary testicular lymphoma (PTL) has poor prognosis with failures in contralateral testis, CNS, and extranodal sites. To prevent these events, we designed an international phase II trial (International Extranodal Lymphoma Study Group 10 [IELSG-10]) that addressed feasibility and activity of conventional chemoimmunotherapy associated with CNS prophylaxis and contralateral testis irradiation. The trial was conducted by the IELSG and the Italian Lymphoma Foundation.

Patients and Methods

Fifty-three patients (age 22 to 79 years) with untreated stage I or II PTL were treated with six to eight courses of rituximab added to cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) every 21 days (R-CHOP21); four doses of intrathecal methotrexate (IT-MTX) and radiotherapy (RT) to the contralateral testis (30 Gy) for all patients and to regional lymph nodes (30 to 36 Gy) for stage II disease.

Results

All patients received R-CHOP21, 50 received CNS prophylaxis, and 47 received testicular RT. With a median follow-up of 65 months, 5-year progression-free survival and overall survival rates were 74% (95% CI, 59% to 84%) and 85% (95% CI, 71% to 92%), respectively. Ten patients relapsed or progressed: two in lymph nodes, five in extranodal organs, and three in the CNS. The 5-year cumulative incidence of CNS relapse was 6% (95% CI, 0% to 12%). No contralateral testis relapses occurred. Ten patients died: lymphoma (n = 6), secondary leukemia (n = 2), heart failure (n = 1), and gastric cancer (n = 1). Grade 3 to 4 toxicities were neutropenia, 28%; infections, 4%; and neurologic, 13%. No deaths occurred as a result of toxicity.

Conclusion

This international prospective trial shows that combined treatment with R-CHOP21, IT-MTX, and testicular RT was associated with a good outcome in patients with PTL. RT avoided contralateral testis relapses, but CNS prophylaxis deserves further investigation.

High response rate and improvement of long-term survival with combined treatment modalities in patients with poor-risk primary thyroid diffuse large B-cell lymphoma: an International Extranodal Lymphoma Study Group and Intergruppo Italiano Linfomi study

The impact of different treatment modalities and prognostic factors on the clinical course of primary thyroid diffuse large B-cell lymphoma (PTDLBCL) is still the subject of research. This study was conducted to clarify these clinical aspects of this disorder. The clinical parameters of 48 patients with PTDLBCL at time of diagnosis were comparable to those of previous studies. Patients underwent either radiotherapy (RT)  ±  surgery (SX), chemotherapy (CHT) alone or in combination with local treatments (RT or SX), or SX followed by CHT and RT. A 90% complete remission (CR) rate was observed among patients who underwent combined treatment modalities (CTM), compared to 76% among the others. The 5-year progression-free survival differed significantly between both groups (p = 0.028). Poor performance status and advanced age correlated with decreased survival. PTDLBCL is a curable disease prevalent in elderly patients. Combined treatment modalities were able to induce an elevated rate of CR, improving long-term survival in younger patients. However, the outcome in elderly patients still remains unsatisfactory.

Clinical activity of bortezomib in relapsed/refractory MALT lymphomas: results of a phase II study of the International Extranodal Lymphoma Study Group (IELSG)

BACKGROUND

The nuclear factor-kappa B activation in mucosa-associated lymphoid tissue (MALT) lymphoma pathogenesis provided the rationale for the evaluation of bortezomib in this malignancy.

PATIENTS AND METHODS

Thirty-two patients with relapsed/refractory MALT lymphoma were enrolled. Thirty-one patients received bortezomib 1.3 mg/m(2) i.v., on days 1, 4, 8, and 11, for up to six 21-day cycles.

RESULTS

Median age was 63 years (range, 37-82 years). Median number of prior therapies was 2 (range, 1-4). Nine patients had Ann Arbor stage I, 7 patients had stage II, and 16 patients had stage IV. Primary lymphoma localization was the stomach in 14 patients; multiple extranodal sites were present in 10 patients. Among the 29 patients assessable for response, the overall response rate was 48% [95% confidence interval (CI) 29% to 67%], with 9 complete and 5 partial responses. Nine patients experienced stable disease and six had disease progression during therapy. The most relevant adverse events were fatigue, thrombocytopenia, neutropenia, and peripheral neuropathy. After a median follow-up of 24 months, the median duration of response was not reached yet. Five deaths were reported, in two patients due to disease progression.

CONCLUSION

Bortezomib is active in relapsed MALT lymphomas. Further investigations to identify optimal bortezomib dose, schedule, and combination regimens are needed since the frequent detection of dose-limiting peripheral neuropathy.

Follicular lymphoma international prognostic index 2: a new prognostic index for follicular lymphoma developed by the international follicular lymphoma prognostic factor project

PURPOSE

The aim of the F2 study was to verify whether a prospective collection of data would enable the development of a more accurate prognostic index for follicular lymphoma (FL) by using parameters which could not be retrospectively studied before, and by choosing progression-free survival (PFS) as principal end point.

PATIENTS AND METHODS

Between January 2003 and May 2005, 1,093 patients with a newly diagnosed FL were registered and 942 individuals receiving antilymphoma therapy were selected as the study population. The variables we used for score definition were selected by means of bootstrap resampling procedures on 832 patients with complete data. Procedures to select the model that would minimize errors were also performed.

RESULTS

After a median follow-up of 38 months, 261 events for PFS evaluation were recorded. beta2-microglobulin higher than the upper limit of normal, longest diameter of the largest involved node longer than 6 cm, bone marrow involvement, hemoglobin level lower than 12 g/dL, and age older than 60 years were factors independently predictive for PFS. Using these variables, a prognostic model was devised to identify three groups at different levels of risk. The 3-year PFS rate was 91%, 69%, and 51% for patients at low, intermediate, and high risk, respectively (log-rank = 64.6; P < .00001). The 3-year survival rate was 99%, 96%, and 84% for patients at low, intermediate, and high risk, respectively (P < .0001).

CONCLUSION

Follicular Lymphoma International Prognostic Index 2 is a simple prognostic index based on easily available clinical data and may represent a promising new tool for the identification of patients with FL at different risk in the era of immunochemotherapy.

Activation of the endoplasmic reticulum stress-associated transcription factor x box-binding protein-1 occurs in a subset of normal germinal-center B cells and in aggressive B-cell lymphomas with prognostic implications

X box-binding protein 1 (Xbp-1) is a transcription factor that is required for the terminal differentiation of B lymphocytes into plasma cells. The Xbp-1 gene is activated in response to endoplasmic reticulum stress signals, which generate a 50-kDa nuclear protein that acts as a potent transactivator and regulates the expression of genes related to the unfolded protein response. Activated Xbp-1 is essential for cell survival in plasma-cell tumors but its role in B-cell lymphomas is unknown. We analyzed the expression of activated Xbp-1 in reactive lymphoid tissues, 411 lymphomas and plasma-cell neoplasms, and 24 B-cell lines. In reactive tissues, Xbp-1 was only found in nuclear extracts. Nuclear expression of Xbp-1 was observed in occasional reactive plasma cells and in a subpopulation of Irf-4(+)/Bcl-6(-)/Pax-5(-) B cells in the light zones of reactive germinal centers, probably representing cells committed to plasma-cell differentiation. None of the low-grade lymphomas showed evidence of Xbp-1 activation; however, Xbp-1 activation was found in 28% of diffuse large B-cell lymphomas, independent of germinal or postgerminal center phenotype, as well as in 48% of plasmablastic lymphomas and 69% of plasma-cell neoplasms. Diffuse large B-cell lymphomas with nuclear Xbp-1 expression had a significantly worse response to therapy and shorter overall survival compared with negative tumors. These findings suggest that Xbp-1 activation may play a role in the pathogenesis of aggressive B-cell lymphomas.

High Numbers of Tumor-Infiltrating Programmed Cell Death 1–Positive Regulatory Lymphocytes Are Associated With Improved Overall Survival in Follicular Lymphoma

Purpose

Tumor microenvironment influences the behavior of follicular lymphoma (FL), although the specific cell subsets involved are not well known. The aim of this study was to determine the impact of programmed cell death 1 (PD-1) –positive inhibitory immunoregulatory lymphoid cells in the clinicobiologic features and outcome of patients with FL.

Patients and Methods

We examined samples from 100 patients (53 men and 47 women; median age, 54 years) at diagnosis, as well as in 32 patients at first relapse, with a recently generated monoclonal antibody against PD-1. The cells were quantified using computerized image analysis. Additional analysis consisted of double immunofluorescence and flow cytometry.

Results

PD-1 expression was alternative to FOXP3 in lymphoid cells from both reactive tonsils and FL. At diagnosis, the median percentage of PD-1–positive cells was 14% (range, 0.1% to 74%). Patients with grade 3 FL, poor performance status, and high serum lactate dehydrogenase showed lower numbers of PD-1–positive cells. After a median follow-up of 6.2 years, patients with PD-1–positive cells ≤ 5% (n = 25), 6% to 33% (n = 50), and more than 33% (n = 25) had a 5-year progression-free survival rate of 20%, 46%, and 48% (P = .038) and overall survival (OS) of 50%, 77%, and 95% (P = .004), respectively. PD-1 and FL International Prognostic Index maintained prognostic value for OS in multivariate analysis. Patients with PD-1–positive cells ≤ 5% showed a higher risk of histologic transformation. At that time, transformed diffuse large B-cell lymphomas had lower percentage of PD-1–positive cells than FL.

Conclusion

A high content of PD-1–positive cells predicted favorable outcome of FL patients, whereas a marked reduction is observed in transformation.