non-GC Subtype Research Articles

Presence, Subtypes, and Prognostic Significance of Tertiary Lymphoid Structures in Urothelial Carcinoma of the Bladder.

To evaluate the presence and subtypes of tertiary lymphatic structures (TLSs) in urothelial carcinoma of the bladder (UCB) and to analyze their associated clinicopathological characteristics and prognostic significance. The study enrolled 580 patients with surgically treated UCB, including 313 non-muscle invasive bladder cancer (NMIBC) and 267 muscle-invasive bladder cancer (MIBC). The presence and subtypes of TLSs were identified by immunohistochemistry (CD20, CD3, Bcl-6, and CD21). TLSs were classified into non-GC (nGC) TLS and GC TLS subtypes based on germinal center (GC) formation. Disease-free survival (DFS) was used as an endpoint outcome to evaluate the prognostic significance of TLS and its subtypes in UCB. TLSs were more common in MIBC than in NMIBC (67.8% vs 48.2%, P < .001), and the tumor-infiltrating lymphocyte (TIL) mean density was significantly higher in MIBC than in NMIBC (24.0% vs 17.5%, P < .001). Moreover, a positive correlation was found between TLS presence and GC structure formation and TIL infiltration in UCB. Endpoint events occurred in 191 patients. Compared to patients with endpoint events, patients without disease progression exhibited higher TIL density and more TLSs (P < .05). Kaplan-Meier curves showed that TLS was associated with better DFS in NMIBC (P = .041) and MIBC (P = .049). However, the Cox multivariate analysis did not demonstrate the prognostic significance of TLS. TLS is heterogeneous in UCB, and that TLS and GC structures are related to TIL density and prognostic events. However, TLS as a prognostic indicator remains unclear, warranting further investigation.

Prognostic impact of miR-125b and miR-155b and their relationship with MYC and TP53 in diffuse large B-cell lymphoma: cell-of-origin classification matters.

Tumoral microRNAs, such as miR-125b and miR-155b, are important gene expression regulators with complex pathogenetic mechanisms. However, their role in DLBCL, especially when cell-of-origin classification is considered, are still to be elucidated. In a series of 139 DLBCL cases considering germinal center (GC) versus nonGC subtypes, we investigated miR-125b and miR-155b expression by in situ hibridization and their association with some immunophenotypic presentations, including MYC, BCL2 and TP53 expression, MYC, BCL2 and BCL6 translocation status, as well as clinicopathological features and outcomes. miR-125b detection was positively correlated to the Ki-67 index (P = 0.035) in the nGC. Considering the GC subgroup, the percentage of miR-125b positive cells was also correlated to either MYC and MYC/BCL2 double expression (P = 0.047 and P = 0.049, respectively). When it comes to nGC patients, miR-155b percentage and intensity, as well as Allred score, were positively correlated to disease progression (P = 0.038, P = 0.057 and P = 0.039, respectively). In a multivariate analysis, GC phenotype was a significant independent factor associated with higher OS (P = 0.007) and, considering the nGC group, although not significant, the expression of TP53, miR-125b and miR-155b seems to be potential prognostic biomarkers in these tumors. This study demonstrated different pathways based on cell-of-origin classification and highlighted different clinical outcomes. miR-125b, miR-155b and TP53 expression may also represent potential prognostic factors in nGC-DLBCL.

Diffuse Large B-Cell Lymphoma in the Public-Sector of Johannesburg, South Africa, in the Era of Widescale Antiretroviral Therapy Use.

Diffuse large B-cell lymphoma (DLBCL) is a high-grade non-Hodgkin lymphoma with increased incidence among people living with HIV-infection (PLWH). Although its frequency is reportedly attenuated by antiretroviral therapy (ART), we have previously shown a similar rate of DLBCL in the post-ART era (2017) in Johannesburg, South Africa compared with that observed when ART had only limited availability in the South Africa state-sector (2007). Here, we present a more detailed analysis of DLBCL in the pre-and post-ART eras in Johannesburg. All cases of DLBCL diagnosed in the state-sector hospitals of Johannesburg in 2007 and 2017 were extracted from the laboratory information system, and factors of interest compared. Most (&gt;85%) were observed among PLWH at both time-points; ART-coverage was significantly higher in 2017 compared with 2007, but with failed immunological recovery in 50% of cases. The immunohistochemically-defined cell of origin differed according to HIV-status; the germinal center (GC) and non-GC subtypes predominating in the PLWH and the HIV-negative group, respectively. MYC-gene rearrangement was more common than is reported elsewhere (22.1%), whereas BCL6 and BCL2 gene rearrangements were less so (14.6% and 0%, respectively). Slight improvement in survival was noted in the post-ART era, but remained poor, with bone marrow involvement and albumin levels ≤30 g/L independently associated with mortality. Although the frequency of DLBCL in Johannesburg has not dropped significantly in the post-ART era, a slight improvement in survival is observed. However, outcomes remain poor, indicating a need for further improvements in care.

Localized Nodal Diffuse Large B Cell Lymphoma: Is Radiotherapy Needed?

Introduction: Diffuse large B-cell lymphoma (DLBCL) is clinically, morphologically and genetically a heterogeneous group of malignant proliferation of large B-cell lymphoid cells. At diagnosis, 25% of DLBCL presents as a localized disease.Therapeutic options for localized DLBCL include short-course or extended-course chemotherapy regimens such as R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) with or without radiotherapy. Regarding the number of cycles, the choice differs in the different oncology services and the role of radiotherapy remains controversial. Another frequent issue regarding this pathology is the prognosis of the cell of origin (COO) in the localized form. In the literature, non-germ center (N-GC) subtype is correlated with lower overall survival (OS) when compared to germinal center (GC) . This lower overall survival of the non-GC subtype has not been reported in patients with localized DLBCL. Objectives: The primary objective is to compare progression-free survival (PFS) and overall survival (OS) at 5 years of different therapeutic strategies, including 3-4 cycles of chemotherapy with or without radiotherapy and 6 cycles of chemotherapy with or without radiotherapy. The study's secondary objective is to compare the prognostic significance of COO, GC and non-GC phenotypes in localized DLBCL. Methods: This is a single-center Brazilian, observational, retrospective, descriptive and analytical study, to be carried out at the referenced Brazilian cancer center, A.C. Camargo Cancer Center. The study included patients aged 18 years and over, with a nodal DLBCL diagnosis located in the period between 2007 and 2020. PFS and OS curves were performed in 5 years of the population stratified by treatment and cell of origin. Results: A total of 90 patients with limited-stage nodal DLBCL were included. The group that received 3 or 4 cycles of chemotherapy (n=5) had PFS and OS at 5 years of 75%. The second group received 6 cycles of chemotherapy (n=41) and had PFS and OS at 5 years of 89% and 92%, respectively. The third group (n=17) received 3 or 4 cycles of chemotherapy and radiotherapy, and had 100% PFS and OS at 5 years. The fourth group (n=27) received 6 cycles of chemotherapy and radiotherapy and had PFS and OS at 5 years of 87%. There was no statistical difference between the groups. A total of 76 patients had immunohistochemical data extracted from pathology reports to determine COO by Hans' algorithm. A GC phenotype was observed in 47% of patients (n=36). At 5 years, the PFS and OS for the GC cohort were 94% for both, and for the non-GC cohort 85% and 87% respectively. Conclusion: There was no significant difference in PFS or OS for the therapeutic strategies, including 3-4 cycles of chemotherapy with or without radiotherapy and 6 cycles of chemotherapy with or without radiotherapy. In this analysis, the cell of origin did not show a difference in 5 year PFS or OS for localized nodal DLBCL.

PB2152: BIOLOGICAL AND CLINICAL CORRELATES OF GALECTIN-3 (GAL-3) EXPRESSION IN DIFFUSE LARGE B-CELL LYMPHOMA (DLBCL)

Background: Gal-3 is the only known member of the group of so-called chimeric galectins. It has 3 structural domains, a NH2 terminal domain with serine phosphatase activity, a repetitive collagen-like domain and a COOH terminal carbohydrate-recognizing domain. Gal-3 is thought to be involved in crucial cellular processes, including regulation of cell proliferation, apoptosis and angiogenesis. Gal-3 promotor contains NF-κB binding sites (Kadrofske et al, 1998). Gal-3 shares the BH1 domain with BCL2 and has antiapoptotic activitiy, but seems to affect different intracellular structures than BCL2 (Akahani et al, 1997). Normal memory B-cell, but not germinal-center cells, express gal-3. More than 50% of DLBCLs express gal-3, but none of Burkitt, follicular, marginal zone and small lymphocytic lymphomas (Hoyer et al, 2004). While preliminary data suggest that gal-3 + DLBCLs have inferior prognosis, its relation to other immunohistochemical markers, cell of origin (COO) and clinical characteristics of lymphomas are unknown Aims: To compare biological and clinical characteristics of gal-3 + and gal-3 – DLBCLs and thus gain insight into its biological function and clinical importance in this tumor type. Methods: We analyzed clinical characteristics (age, sex, IPI factors, response to treatment, event-free survival (EFS) and overall survival (OS)), immunohistochemical expression of gal-3, BCL2, VEGF and NF-κB (p65), and cell of origin (COO) as determined by Hans’ algorithm, in newly diagnosed DLBCL patients treated with R-CHOP or similar regimens. All markers were evaluated using commercially available monoclonal antibodies. Results: 123 patients were included in the study with a median follow-up of survivors of 68 months. Gal-3 was positive in 69 (56.1%), negative in 51(41.4%) and undetermined in 3. Patients with higher IPI, non-GC subtype and NF-κB + expressed gal-3 more frequently (Table). In univariate analysis gal-3 expression was not a statistically significant prognostic factor for OS and EFS in the whole group of patients (p=0.16 for EFS and p=0.19 for OS). However, BCL2 + patients fared significantly worse if they coexpressed gal-3 (EFS at 2 y 44% vs 73% (p=0,002) OS at 2 y 50% vs 74% (p=0,006)). Gal-3 expression had no influence on the outcome of BCL2- patients. In multivariate analysis of influence of immunohistochemical markers on EFS and OS, BCL2 was the only significant factor, while gal-3 showed a strong trend (p=0.068 for EFS and 0.093 for OS). If IPI was introduced into the model, gal-3 expression lost its significance. Image:Summary/Conclusion: Our results are in accordance with experimental data indicating that NF-κB stimulates gal-3 expression and that gal-3 potentiates the antiapoptotic effect of BCL2. Gal-3 is more frequently expressed in advanced-stage DLBCLs and those of non-GC subtype, consistent with its putative proliferative/antiapoptotic effect and its expression in memory B- but not germinal-center cells.

Long-term outcomes and circulating tumor DNA analysis from a phase I/II study of lenalidomide and obinutuzumab with CHOP for newly diagnosed diffuse large B-cell lymphoma.

7553 Background: Diffuse large B-cell lymphoma (DLBCL) can be cured with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (RCHOP), but a third of patients (pts) experience treatment failure. Randomized trials comparing RCHOP with modified regimens, including replacing R with obinutuzumab (O, CD20 antibody, Vitolo JCO 2017) and adding lenalidomide (L) to RCHOP (Nowakowski JCO 2021), have not significantly improved outcomes. The combination of L and O may have synergy via an enhanced NK-cell mediated antibody dependent cellular cytotoxicity. We hypothesized combining L and O with CHOP (LOCHOP) would be an effective and well tolerated treatment of DLBCL. Methods: In this single center phase Ib/II study (NCT02529852) pts with untreated CD20+ DLBCL received 6 cycles of CHOP with O 1000mg IV on days (D) 1, 8, and 15 during cycle 1 and D1 during cycles 2-6, and L 15 mg orally on D1-14 of each cycle. Growth factor and thromboembolism prophylaxis were mandated. The primary objectives were to determine the maximum tolerated dose (MTD) of L and efficacy of LOCHOP. Plasma samples were collected for circulating tumor DNA (ctDNA) analysis. Results: Fifty-three pts were enrolled, 6 in phase Ib and 47 in phase II. No dose limiting toxicities were experienced in phase Ib at an MTD of 15 mg of L. Median age was 62 years, 35 (66%) pts had stage III/IV disease, 12 (23%) an IPI &gt; 2, and 26 (49%) and 22 (42%) were germinal center (GC) and non-GC subtype (5 not classified) by Hans algorithm. At end of therapy, 50 pts were evaluable, overall response: 49 (98%), complete response: 45 (90%). Median follow up was 4.5 years and 4-year progression free and overall survival rates were 87.4% and 91.3%. No characteristics were associated with differences in outcomes. Any grade and grade 3-4 adverse events (AEs) were experienced by 100% and 70% of pts. Grade 3-4 AEs included neutropenia (38%), thrombocytopenia (17%), fatigue (13%), neutropenic fever (13%), and infection (9%). Four (8%) pts developed venous thromboembolism. At study entry, 31/33 (94%) profiled pts had detectable ctDNA with CAPP-Seq, 24% had high ctDNA ( &gt; log 2.5 hGe/ml) and 24/31 (77%) were evaluable by LymphGen classifier: molecular subtypes included EZB (5, 21%), ST2 (5, 21%), MCD (4, 17%), and other (9, 38%). All 5 EZB and 4/5 ST2 pts were GC subtype while 2/4 MCD pts were non-GC (1 GC, 1 not classified). With LOCHOP, 13/18 (72%) and 11/15 (73%) pts achieved early and major molecular response (Kurtz JCO 2018). By PhasED-Seq (Kurtz Nat Biotechnol 2021), 16/18 (89%) had no detectable ctDNA after ≥5 cycles. Conclusions: LOCHOP demonstrates high efficacy and tolerability in newly diagnosed DLBCL, leading to a high rate of undetectable minimal residual disease by ctDNA. Noninvasive molecular subtyping is feasible as a supplement to tissue diagnosis and should be incorporated in future studies aiming to improve on RCHOP. Clinical trial information: NCT02529852.

Programmed cell death-ligand 1 (PD-L1)+ tumour cells and low-reacting programmed cell death 1 (PD1)+ tumour-infiltrating lymphocytes predict poor prognosis in Epstein-Barr virus+ diffuse large B-cell lymphoma.

Epstein-Barr virus (EBV)+ diffuse large B-cell lymphoma (DLBCL) has specific tumour cell characteristics, and these patients have worse outcomes than EBV-negative DLBCL patients. We compared 38 EBV+ DLBCL patients with 43 methotrexate-associated EBV+ B-cell lymphoproliferative disorders (MTX+/EBV+ BLPDs) and 30 non-germinal centre (GC) subtype DLBCL. Lymphoma cells of the EBV+ DLBCL group were positive for BCL2 in 17 patients (44.7%), CMYC in 23 patients (60.5%), and p53 in 33 patients (86.8%), which was significantly higher than in the MTX+/EBV+ BLPD group (P < 0.05), and were positive for CD30 in 29 patients (76.3%), compared with two in non-GC subtype DLBCL (6.7%) (P < 0.0001). Significantly more EBV+ DLBCL patients (n = 16, 42.1%) had programmed cell death-ligand 1 (PD-L1)+ tumour cells than patients with non-GC subtype DLBCL (n = 5, 16.7%; P = 0.024), and PD-L1+ tumour cells were more common in advanced stages than in early stages (P = 0.048). Twenty-five EBV+ DLBCL patients (69.4%) had few reactive PD1+ tumour-infiltrating lymphocytes (TILs), compared with 12 patients with MTX+/EBV+ BLPDs (37.5%) (P = 0.008). In the EBV+ DLBCL group, CD30, BCL2, CMYC, and p53 expression was not related to patient prognosis. Poor outcomes were associated with PD-L1+ tumour cells (P = 0.001) and low-reacting PD1+ TILs (P = 0.02), while their combination conferred a worse outcome (P < 0.0001). Immune evasion by PD-L1+ tumour cells and exhaustion of PD1+ TILs may occur in EBV+ DLBCL patients, and PD-L1/PD1 interactions may influence tumour progression and poor prognosis.

The Genetic Landscape in Elderly DLBCL Aged > 75 Years in the Australasian Leukaemia & Lymphoma Group NHL29 Iric Trial Identifies New Targetable Mutations

Background: Approximately 40% of patients with diffuse large B-cell lymphoma (DLBCL) are &amp;gt;70 years old and have poor clinical outcomes attributable to treatment-related factors or to disease biology. Genotyping data in elderly DLBCL patients is limited because of lack of representation in clinical trials. R-mini-CHOP is better tolerated than R-CHOP in elderly DLBCL but with reduced efficacy. The addition of ibrutinib to R-CHOP has been shown to be effective in younger pts aged &amp;lt; 60 years but is associated with poor tolerability and outcomes in older patients. The ALLG Ibrutinib with R-mini-CHOP (IRiC) study, a prospective multicentre single-arm phase II study in elderly (≥ 75 years) DLBCL patients provided an opportunity to genotype this uncommon cohort. We therefore aimed to map the genetic landscape of mutations in elderly DLBCL and compare them to a non-trial younger cohort. Methods: Mutations in genes commonly associated with DLBCL were assessed in 55 IRIC study patients with a median age of 81 years (75-91 years) and a gender ratio of 1.0 (27 M/28 F). A cohort of 51 non-trial patients withde novoDLBCL treated with anthracycline-based regimens was also genotyped. The median age of the control group was 65 years (29-91 years) with a gender ratio of 1.2:1 (28 M/23 F). The cell of origin (COO) measured using gene expression profiling on 39/55 trial patients (non-GC=13, GC= 22, unclassified= 4), and Hans algorithm on 45/51 non-trial patients (non-GC=14, GC=31) was comparable (p=0.571). Outcome data was available at a median follow-up of 18 and 40 months for the trial and non-trial cohorts respectively. We extracted genomic DNA from and performed next generation sequencing on diagnostic formalin-fixed paraffin-embedded or fresh frozen tissue samples using a customized capture library (SureSelectXT Target Enrichment System, Aqilent Technologies) covering genes involved in lymphomagenesis. The purified libraries were sequenced on the Illumina NextSeq500 platform at AGRF (Australian Genome Research Facility, Australia). Mutations in the following genes were compared across the two cohorts: ARID1A, BCL2, BTG1, BTG2, CARD11, CCND3, DTX1, EP300, ETS1, EZH2, FOXO1, GNA13, HIST1H1C, IKBKB, IRF8, KDM2B, KLHL6, MYC, MYD88, NOTCH1, NOTCH2, PIK3CD, PIM1, PRDM1, PTEN, PTPN21, SGK1, SPEN, STAT3, TET2, TNFAIP3, TNFRSF11A, TNFRSF14, TP53 and TRAF5. Statistical analysis for nominal data was done using the chi-square test and for ordinal data using the Kruskal-Wallis test (p &amp;lt; 0.05= significant). Kaplan-Meier curves were calculated for patients with and without each mutation and the curves compared using a log-rank approach. Results: Patients were divided into 2 groups, IRiC trial cohort aged &amp;gt;75 years (n=55) + non-trial elderly patients &amp;gt;75 years (n=9) =elderly cohort(n=64) and non-trialnon-elderly cohortof patients &amp;lt; 75 years (n=42). As expected, elderly patients were more likely to have high-risk disease with higher IPI of ≥ 3 (n=42, n=17, p=0.009). There was no significant difference in gender or COO. The frequency of mutations in the elderly (n=64) was compared to the non-elderly cohort (n=42). NOTCH2 was the most common mutation irrespective of age (34 [53%]; 16 [38%], p=0.129). Notably, we found that mutations in MYC (8 [12.5%]; 0, p= 0.021), PTEN (17 [26.5%]; 4 [9%], p=0.045) and TET2 (28 [43.7%]); 7 [16.6%], p=0.004) were more frequent in the elderly. As expected, MYD88 and CD79B mutations were more frequently associated with non-GC subtype (p=0.001). No other associations with COO were identified. No clear prognostic individual genes or gene clusters could be identified in the trial or the elderly cohort. Ibrutinib-responsive (MYD88 [L265P n=7] and CD79B [n=11]) and ibrutinib-resistant mutations (CARD11 [n=6] or PIM1 [n=12]) did not show clear associations with response rate, overall survival or progression-free survival. Conclusions: Our study found that the mutational profile of elderly DLBCL patients aged ≥ 75 years is enriched for targetable mutations in MYC, PTEN and TET2 compared to those &amp;lt; 75 years. PTEN and TET2 are tumour suppressors and MYC is an oncogene with an important regulatory role in cell growth and proliferation. We hypothesize that hypo-methylating agents targeting TET2, BET inhibitors in MYC mutated tumours and PI3K inhibitors to target PTEN deficient lymphoma may help improve clinical outcomes in elderly DLBCL. No clear prognostic markers were identified in this small cohort. Disclosures Trotman: Celgene:Research Funding;BeiGene:Research Funding;Takeda:Research Funding;PCYC:Research Funding;F. Hoffmann-La Roche:Research Funding.Verner:Janssen Cilag Pty Ltd.:Research Funding.Gandhi:Celgene:Research Funding;Bristol-Myers Squibb:Research Funding;Mater Research:Current Employment;Janssen-Cilag:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Roche:Other: Travel, accommodation, expenses ;Genentech:Honoraria;Gilead Sciences:Honoraria;Amgen:Honoraria;Merck Sharp &amp; Dohme:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.Gandhi:Integrated Sciences:Current Employment.Talaulikar:Takeda:Research Funding;Amgen:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Janssen:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau;Roche:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

MYD88 L265P mutation detected by digital PCR as a prognostic factor in patients with diffuse large B-cell lymphoma in rituximab era

The central nervous system (CNS) relapse in patients with diffuse large B cell lymphoma (DLBCL) is fatal as there are no effective rescue treatments. To test if the presence of the MYD88 L265P mutation is a prognostic factor for secondary CNS relapse, we carried out the digital PCR analysis of 134 samples from patients with DLBCL at diagnosis. The MYD88 L265P mutations were detected in 22 (16.4%) patients, particularly in those with a non-GC subtype, CD5-positive, high absolute monocyte count, extra-nodal lymphoma, and B symptoms. Nine patients showed low signal in digital PCR but were deemed positive for the MYD88 L265P mutation by the nested allele-specific PCR. The remaining 103 patients were negative according to the results of both the PCR analyses. With a median follow-up period of 64 months, the carriers of MYD88 L265P mutation exhibited inferior CNS relapse-free survival at 5 years (53.2% versus 96% and 100%, respectively, P < 0.001) with a significant effect of the mutation demonstrated by the multivariate analysis (hazard ratio 5.1; 95% CI 1.2-22.9, P = 0.02). This suggests that the MYD88 L265P mutation plays a critical role in the progression of DLBCL to CNS.

Cell of Origin and Treatment Impact on the Outcome of Monomorphic Post-Transplant Lymphoproliferative Disorder-Diffuse Large B-Cell Lymphoma Subtype

Introduction : Cell of origin (COO) determination of diffuse large B-cell lymphoma (DLBCL) is important, as it has prognostic and therapeutic relevance. Patients with germinal center (GC) like DLBCL have more favorable outcomes than those with non-GC DLBCL, when treated with standard immunochemotherapy. In monomorphic post-transplant lymphoproliferative disorder (PTLD), DLBCL subtype, the biologic significance of COO is not well established. The aims of this study were to evaluate the impact of the COO on clinical presentation, outcome and response to different treatment regimens. Methods : We conducted a retrospective review of all monomorphic PTLD of the DLBCL subtype diagnosed and treated at Columbia University from 2000-2018. COO classification into GC and non-GC subtype was determined by immunohistochemistry using the Hans algorithm. In situ hybridization for Epstein-Barr encoded small RNAs (EBER) was performed to evaluate for EBV infection of the neoplastic lymphocytes. Outcomes according to therapeutic regimens were assessed using the revised response criteria for malignant lymphoma (2007). Overall survival (OS) and progression free survival (PFS) were estimated by the Kaplan-Meier method and compared by the log rank test. Results : Cell of origin: Biopsy material for COO subtyping was available for 49 monomorphic PTLD-DLBCL diagnosed during the study period. By immunohistochemistry 20/49 cases (40.8%) were GC and 29/49 cases (59.2%) were non-GC. Median age of presentation was 52 years (range 3-72) and 55 years (range 3-75), for the GC and non-GC respectively. Median time from transplant to PTLD onset was 3 years, range 7 months-25 years vs. 6 years, range 2 months-24 years for GC vs non-GC respectively. There was no significant difference in the incidence of EBV positivity, immunosuppressive therapy, organ transplanted, stage, LDH, ECOG and IPI between the 2 groups. Of note, extranodal involvement, specifically of the gastrointestinal tract was extremely common in both subtypes (16/20 [80%] in GC and 25/29 [86%] in non-GC). While acknowledging the heterogeneity of therapies administered, a trend suggesting better prognosis for the GC type was noted, although not statistically significant. The median PFS was 151.0 months for GC vs 17.0 months in non-GC (p= 0.1095), while the median OS was 151.0 months for GC vs 36.7 months for non-GC (p=0.1006) (Figure 1A, 1B). Impact of Treatment: Of the 49 cases, 44 were adults (age≥18). The two most common first line therapies administered were R-EPOCH (25) and R-CHOP (9). Ten patients received 6 other therapies including Rituximab monotherapy (3), CHOP (2), palliative care (2), RCEOP (1), EPOCH (1), and radiation (1). When focusing on patients who received R-CHOP or R-EPOCH as initial therapy, no significant differences in age, stage, LDH, extranodal disease, ECOG, IPI, immunosuppressive therapy and COO was identified between the 2 groups. The complete response (CR) rate for R-CHOP was 6/9 (66.6%) vs. 21/25 (84%) for R-EPOCH (p= 0.2701). Primary refractory disease was present in a third of the patients receiving R-CHOP vs. (4/25) 16% of the patients treated with R-EPOCH (p=0.2701). Treatment related mortality was low in both groups (1/9 (0.1%) vs 1/25 (0.04%) patients died during first line therapy with RCHOP vs REPOCH respectively). No difference was seen in terms of PFS and OS in the 2 groups. Median PFS and OS for RCHOP was 80.0 and 83.9 months respectively, the medians for R EPOCH were not reached (log-rank test p= 0.5430, 0.2855 for PFS and OS, respectively) (Figure 1C-1D). When the OS and PFS curves for RCHOP and REPOCH were analyzed based on COO, again no difference was noted. Conclusions : Non-GC subtype is more common than GC in monomorphic PTLD DLBCL. Clinical characteristics, EBV infection and time of onset post transplant is not different in the 2 subtypes. There is a trend suggesting better PFS and OS of PTLD DLBCL GC subtype, although not statistically significant, mirroring the outcome of GC vs non-GC COO in DLBCL of immunocompetent patients. With regard to therapy, R-EPOCH did not improve OS or PFS when compared to R-CHOP, but did not result in increased toxicity or treatment related mortality, which in our series was extraordinarily low for both therapies (&lt;=0.1%). Given the retrospective nature of our analysis, further studies of a larger cohort of patients is ongoing to validate these observations. Disclosures Sawas: Seattle Genetics, Gilead, Daiichi Sanko: Consultancy; Affimed: Research Funding. Lue:Kymera Therapeutics: Honoraria; Astex Pharmaceuticals: Honoraria. Marchi:Spectrum Pharmaceuticals, Verastem Oncology: Research Funding. Radeski:Corvus Pharmaceuticals: Research Funding. O'Connor:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Mundipharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Other: Travel Support, Research Funding; ADCT Therapeutics, Affimed, Agensys, Merck, Seattle Genetics, Spectrum, Trillium, and Verastem Oncology.: Research Funding.

Phase I Trial of Carfilzomib + R-CHOP (CarR-CHOP) for Frontline Treatment of Patients with Diffuse Large B-Cell Lymphoma (DLBCL)

Phase I Trial of Carfilzomib + R-CHOP (CarR-CHOP) for Frontline Treatment of Patients with Diffuse Large B-Cell Lymphoma (DLBCL)

Machine Learning Provides an Accurate Classification of Diffuse Large B-Cell Lymphoma from Immunohistochemical Data

Background: The classification of diffuse large B-cell lymphomas into Germinal Center (GCB) and non-GC subtypes defines disease subgroups which are different both in terms of gene expression and prognosis. Given their clinical significance, several classification algorithms have been designed, some by making use of widely availability immunohistochemical techniques. Despite their high concordance with gene expression profiles (GEP) and prognostic value, these algorithms were based on technical and biological assumptions that could be improved in terms of performance for classification. Methods: In order to overcome this limitation, a new algorithm was obtained by analyzing a previously published dataset of 475 patients by using an automatic classification tree method. Results: The resulting algorithm classifies correctly 91.6% of the cases when compared to GEP, displaying a Receiver-Operator Characteristic (ROC) area under the curve of 0.934. Noteworthy features of this algorithm include the capability to classify GEP-unclassifiable cases and a significant prognostic value, both in terms of overall survival (60 months for non-GC vs not reached for GCB, P = 0.007) and progression-free survival (61.9 months vs not reached, P = 0.017). Conclusion: By using a machine learning classification method that avoids most pre-assumptions, the novel algorithm obtained is accurate and maintains relevant features for clinical implementation.

Smoothened Stabilizes and Protects TRAF6 from Proteosomal Degradation: A Novel Non-Canonical Role of Smoothened with Implications in Lymphoma Biology

Tumor necrosis factor receptor-associated factor 6 (TRAF6), an (K63) E3-ligase, plays a crucial role in many biological processes and its activity is relevant in the biology of multiple cancers including diffuse large B cell lymphoma (DLBCL). Although molecules that trigger TRAF6 activation have been defined, those that stabilize TRAF6 levels and/or enhance TRAF6 function remain largely unclear. Previously, we found that activation of smoothened (SMO) with recombinant Hedgehog (Hh) ligand increased the binding between SMO with TRAF6, as well as TRAF6 protein levels (Blood 2013; 121:4718-28). In addition, transient overexpression of SMO resulted in increased K63-Ub of both TRAF6 and NEMO indicating stabilization of these proteins resulting in NF-kB activation. This is relevant, as more recently we found that TRAF6 amplifies pAKT signaling in DLBCL and that TRAF6 is the dominant E3 ligase for the K63-Ub of AKT in DLBCL. Moreover, TRAF6 recruitment to the cell membrane, and stabilization of its ubiquitination profile are facilitated by SMO. SMO is a member of the Frizzled-class G-protein-coupled receptor (GPCRs) and is traditionally known for its role as signal transducer in canonical Hedgehog (Hh) signaling. These observations prompted us to investigate whether the ability of SMO to increase TRAF6 levels is limited to ligand induced signaling, whether it contributes to chemoresistance in DLBCL cells, and whether SMO directly participates in controlling TRAF6 levels.To confirm the regulatory role of SMO in the TRAF6/AKT axis in DLBCL cells (HBL1 and HT) and further outline the nature of the underlying regulation, we measured the impact of activation of the Hh pathway with recombinant Shh ligand on TRAF6 levels, with and without SMO knockdown or recombinant SMO overexpression. Canonical Hh signaling results in the activation of the GLI1 transcription factor and the subsequent elevation of GLI1 mRNA levels is an established indicator of activation of the Hh pathway. However, neither SMO activation nor the knockdown of GLI1 had a significant impact on TRAF6 mRNA levels. These findings indicate that TRAF6 is not transcriptionally regulated by SMO signaling through GLI1 (canonical Hh signaling). In contrast, overexpression of SMO or siRNA knockdown of SMO resulted in an increase or decrease of TRAF6 protein levels, respectively. Consistent with the decrease of AKT activation (pAKT T308 and S473) after TRAF6 knockdown, the increase in TRAF6 levels that follows SMO overexpression resulted in an increase in the levels of AKT phosphorylation. Altogether, these observations suggest a post-translational regulation of TRAF6 by SMO. Indeed, stable knockdown of SMO dramatically reduces the half-life of TRAF6 in both HBL1 and HT cells in the presence of cyclohexamide. Furthermore, overexpression of SMO increases K63-Ub of both TRAF6 and AKT. In contrast, the SMO induced decrease in K48-Ub occurred only for TRAF6 but not for AKT. These data link the SMO-stimulated activation of TRAF6 to the enhancement of AKT signaling and protection of TRAF6 from proteasomal degradation. Mechanistically, we found that SMO, through its C-terminal tail, stabilizes TRAF6 and protects TRAF6 from proteosomal degradation, an effect mediated by ubiquitin-specific protease-8 (USP8). Importantly, this functional link between SMO and TRAF6 is reflected in DLBCL patient samples where high expression of both molecules correlates with poor prognosis.Resistance to DXR is a serious challenge in the treatment of DLBCL, and activated AKT is known to contribute to DXR resistance in multiple cancers including DLBCL. We evaluated whether SMO and TRAF6 support resistance to DXR in DLBCL cell lines. We exposed HT and HBL1 cells as well as their counterparts with stable knockdown of TRAF6 or SMO to DXR for 96hrs. Cell viability after exposure to DXR was determined by an Annexin V and PI staining assay. Silencing SMO or TRAF6 dramatically decreased cell survival after treatment with DXR.In summary, we report that SMO is needed to facilitate and maintain TRAF6-dependent elevated pAKT levels in DLBCL cell lines of germinal (GC) and non-GC subtypes, and that the SMO/TRAF6 axis contributes to DXR resistance in DLBCL. Our study reveals a novel and potential central cell survival signaling mechanism in which SMO stabilizes and protects TRAF6 from proteosomal degradation. DisclosuresLossos:Affimed: Research Funding.

CXCL-8/IL8 Produced by Diffuse Large B-cell Lymphomas Recruits Neutrophils Expressing a Proliferation-Inducing Ligand APRIL.

Tumor-infiltrating neutrophils have been implicated in malignant development and progression, but mechanisms are ill defined. Neutrophils produce a proliferation-inducing ligand APRIL/TNFSF13, a factor that promotes development of tumors from diverse origins, including diffuse large B-cell lymphoma (DLBCL). High APRIL expression in DLBCL correlates with reduced patient survival, but the pathway(s) dictating APRIL expression are not known. Here, we show that all blood neutrophils constitutively secrete APRIL, and inflammation-associated stimuli, such as TNF, further upregulate APRIL. In a significant fraction of DLBCL patients, tumor cells constitutively produced the ELC-CXC chemokine CXCL-8 (IL8), enabling them to recruit APRIL-producing blood neutrophils. CXCL-8 production in DLBCL was unrelated to the cell of origin, as APRIL-producing neutrophils infiltrated CXCL-8+ DLBCL from both germinal center (GC) and non-GC subtypes. Rather, CXCL-8 production implied events affecting DNA methylation and acetylation. Overall, our results showed that chemokine-mediated recruitment of neutrophils secreting the tumor-promoting factor APRIL mediates DLBCL progression. Cancer Res; 77(5); 1097-107. ©2016 AACR.

A Multi-Institutional Outcomes Analysis of Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma Treated with Ibrutinib

Background: Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with distinct survival differences according to molecular subtype with superior outcomes in patients with the germinal center B cell-like (GC) subtype as compared to those with the activated B cell-like (ABC) subtype. Efficacy data for single-agent ibrutinib in patients with relapsed/refractory (r/r) DLBCL are limited to a single clinical trial of 80 patients. In that study, higher response rates were observed for r/r ABC-DLBCL compared to GC-DLBCL (37% vs. 5%), when assigned by gene expression profiling (GEP). The response rate of those with unknown/unclassifiable DLBCL was 22%. Despite biologic rationale for selective cytotoxicity of ibrutinib for ABC-DLBCL, it is not clear that such preferential activity will be observed when subtyping based on immunohistochemical (IHC) staining is used, as the correlation with subtype determined by GEP and IHC is imperfect. Furthermore, GEP is time consuming and expensive so IHC is used in clinical practice to differentiate GC from non-GC, the latter of which includes both ABC and unclassifiable DLBCL. We retrospectively analyzed outcomes of patients with r/r DLBCL treated with ibrutinib at a number of large academic medical centers.Methods: We reviewed medical records of all patients with DLBCL treated with ibrutinib at five U.S. tertiary-care cancer centers from 2013 to 2016. We included patients with de novo DLBCL as well as those transformed from indolent lymphoma if the ibrutinib was given for the DLBCL histology. Patients were excluded if they received ibrutinib for ≤ 14 days. Molecular subtype (GC vs non-GC) was determined by local pathology findings and/or the investigator’s application of the Hans algorithm. Categorical variables were compared between groups using the Chi-square test. Outcomes were calculated from the date of initiation of ibrutinib. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method and compared using the log-rank test.Results: Thirty five patients met inclusion criteria (27 de novo and 8 transformed DLBCL). The median age at diagnosis was 61 years (range 38-88) with 66% men.By Hans IHC criteria, there were 21 cases of non-GC, 9 GC and 5 were unknown.The median number of treatments prior to ibrutinib was 3 (range 1-8). 30% of patients had undergone prior autologous stem cell transplant. Characteristics including age, gender, transformed versus de novo, relapsed versus refractory, number of prior therapies, and prior use of transplant did not significantly differ between subgroups. The overall response rate (ORR) to ibrutinib was 29% with 4 patients achieving a complete response (CR) and 6 achieving a partial response (PR). When evaluated by subtype assigned by IHC, GC-DLBCL patients had an ORR of 44% and non-GC-DLBCL patients had an ORR of 19%. There was no significant difference in the rates of CR, PR, stable disease, or progressive disease between the subtypes (p=0.185) or between de novo ortransformed disease (P = 0.114). The median progression-free survival (PFS) was comparable for patients with the GC, non-GC, and unknown subtype (3.9, 2.2, and 4.1 months, respectively, P = 0.382, Figure). The median overall survival (OS) was longer for patients with the GC subtype (10.5 months) compared to 5.5 months for patients with the non-GC subtype, and 9.7 months for those with unknown subtype but this difference was not statistically significant (P=0.564).Figure: Progression Free Survival of r/r DLBCL Patients Treated with Ibrutinib, based on Hans Algorithm SubtypeConclusions: Responserates to single agent ibrutinib in the GC and non-GC subtypes of r/r DLBCL do not appear different when using Hans algorithm to assign subtypes. PFS and OS were modest in both groups and not statistically different. In conclusion, until GEP or other molecular technologies such as Nanostring are in more widespread use for routine subtyping of DLBCL, caution is advised when selecting patients for subtype-specific therapy, as clinical outcomes for patients receiving ibrutinib may not differ by cell of origin as determined by IHC. [Display omitted] DisclosuresReddy:celgene: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees; GILEAD: Membership on an entity's Board of Directors or advisory committees; INFINITY: Membership on an entity's Board of Directors or advisory committees. Shadman:Pharmacyclics: Honoraria, Research Funding. Smith:Spectrum: Honoraria; Celgene: Honoraria; Abbvie: Research Funding; Genentech: Honoraria.

Preclinical Evaluation of Ibrutinib for Central Nervous System Lymphoma

IntroductionPrimary CNS lymphoma (PCNSL) is a diffuse large B-cell lymphoma (DLBCL), predominantly of non-germinal center (non-GC) subtype. Currently available treatments remain disappointed with a non-optimal complete remission rate and a high relapse rate. As such, novel therapeutic agents are urgently needed. Constitutive activation of the NF-kB pathway via mutations in B cell receptor (BCR) (CD79B) and mutation of MYD 88 and TBL1XR1 pathways plays an important role in PCNSL. Ibrutinib, an inhibitor of BCR signaling, has been found to have significant therapeutic activity in relapsed or refractory non-CNS non-GC DLBCL that display similar NFKB mutational patterns. We have performed a CNS pharmacokinetic (PK) study of Ibrutinib and evaluated its therapeutic activity against CNS lymphoma (CNSL) in murine models.MethodsCNS PK study in mice - The first study was done in a CNSL model created by intracerebral implantation of luciferase-transfected lymphoma cells (MC116) in nude mice in comparison to healthy nude mice without lymphoma cell implantation (N=5 per group). Once the tumor activity was confirmed by bioluminescence imaging in CNSL group, all the mice were treated with ibrutinib 12 or 30 mg/kg/day by oral gavage (OG) for 5 days. Blood and brain were collected 2 hours after the last dose. Ibrutinib was measured by ultra performance liquid chromatography with tandem mass spectrometry.Cerebro-spinal fluid (CSF) PK study in Sprague-Dawley (SD) rats - Ibrutinib 50 mg/kg single dose was given by OG (N=6). Microdialysates of CSF were collected from a ventricle of the brain and a carotid artery via microdialysis catheters every hour for 13 hours post-treatment. Drug concentrations were determined by capillary electrophoresis with laser detection.Preclinical therapeutic evaluation - A murine CNS lymphoma model was created by intracerebral injection of the OCI-Ly10 non-GC DLBCL cells, which were confirmed to have CD79 A and MYD 88 mutations and show high sensitivity to Ibrutinib in vitro. Animals were sacrificed if they showed severe clinical signs or symptoms or >20% weight loss. Ibrutinib 30 mg/kg was administered by OG daily starting at day 7 post-implantation and until the last sacrifice in the control group treated with vehicle. Therapeutic efficacy was determined by Kaplan-Meier survival analysis using date of sacrifice as endpoint.ResultsCNS PK study in mice - 1) Ibrutinib levels in plasma, normal brain tissue and brain-tumor were analyzed. Ibrutinib was not detected in healthy control mice treated with vehicle. In healthy mice treated with ibrutinib (12 mg/kg and 30 mg/kg), Ibrutinib mean plasmatic levels were 9.31 (±3.56) ng/mL and 42.2 (±20.9) ng/mL respectively. At 12 mg/kg dose level, ibrutinib was detectable but not quantifiable in brain tissue. After treatment with 30 mg/kg,iIbrutinib mean levels were 0.0077 (±0.0053) and 0.0071 (±0.00483) ng/g tissue in right and left cerebral hemispheres respectively. In CNSL mice treated with ibrutinib (12 mg/kg and 30 mg/kg), Ibrutinib mean plasmatic levels were 12.03 (±9.04) ng/mL and 42.64 (±42.04) ng/mL respectively, brain ibrutinib levels were 0.008 (±0.005) and 0.007 (±0.003) ng/g tissue for tumor-bearing right hemisphere and non-tumor bearing left hemisphere respectively for 30 mg/kg, while brain ibrutinib level was detectable but not quantifiable at 12mg/kg.CSF PK study in SD rats - CSF penetration of ibrutinib was determined to be ~5.2 % as calculated by area under the curve (AUC) ratio of CSF and blood samples. Cmax in CSF is ~0.35 uM, which is significantly higher than published EC50 concentrations for DLBCL cell lines.Preclinical therapeutic evaluation -Ibrutinib showed an excellent therapeutic activity with significant prolongation of survival (p=0.0137) (fig 1). At a median follow-up of 112 days, the median survival in treated CNSL group is 56 days compared to 33 days in the control group. At the end of the follow-up 33% of animals in treated CNSL group are still alive without treatment.ConclusionIbrutinib achieves high concentrations in brain and CSF in murine CNS PK models with promising single-agent preclinical therapeutic activity against CNS lymphoma in a murine model. Further studies to develop combination regimen are ongoing. [Display omitted] DisclosuresSoussain:Roche: Research Funding; Celgene: Research Funding; Pharmacyclics: Research Funding.

Rituximab-Lenalidomide (REVRI) in Relapse or Refractory Primary Central Nervous System (PCNSL) or Vitreo Retinal Lymphoma (PVRL): Results of a "Proof of Concept" Phase II Study of the French LOC Network

BackgroundPrimary CNS lymphoma (PCNSL) is a diffuse large B-cell lymphoma (DLBCL), predominantly of non-germinal center (non-GC) subtype. Despite improvement of therapeutic results since the introduction of high-dose methotrexate (MTX) in first-line treatment, improvements of therapeutic results are needed in PCNSL, both in first-line treatment and at relapse. The roles of consolidation and maintenance therapy need to be addressed as well. The association of Rituximab and Lenalidomide has shown activity in non-CNS non-GC DLBCL, but its activity in PCNSL was unknown.MethodsIn this prospective, multicenter open-label phase II study, we enrolled patients over 18 with a refractory or relapse PCNSL or primary vitreo-retinal lymphoma (PVRL) of DLBCL type. The treatment consisted in an induction phase with 8 cycles of 28 days with R2 (Rituximab 375/m2 IV D1; Lenalidomide 20 mg/D D1-D21 for the first cycle then 25 mg/D D1-D21 for the subsequent cycle in the absence of hematologic toxicity), followed, in responder patients by a maintenance phase with 12 cycles of 28 days with Lenalidomide alone (10 mg/D, D1-D21). Corticosteroids were allowed during the first induction cycle in case of a threatening or symptomatic edema. Deep vein thrombosis prophylaxis was mandatory. Patient who received a complete month of treatment were evaluable for response. The primary end-point was the objective response rate (ORR) at the end of the induction phase, according to the international primary CNS lymphoma collaborative group (IPCG) criteria. The analysis was based of a Fleming's two-step design (P0 = 10 %; P1= 30%). A pilot exploration of circulating NK and T cells before and after treatment and correlation with therapeutic response was conducted. This study is registered with ClinicalTrials.gov, number NCT01956695ResultsBetween September 17, 2013 and September 29, 2015, fifty patients (median age: 69, range 46-86) were recruited from 10 centers. All the patients had previously received high-dose (HD) MTX. Median number of previous lines of chemotherapy was 2 (range, 1-4). Nine patients had previous received an HD chemotherapy followed by hematopoetic stem cell rescue. Initial diagnoses were PCNSL (n = 42) and PVRL (n = 8). At time of inclusion in the study, diagnoses were PCNSL (n = 41) and PVRL or isolated intra-ocular (IO) relapse of PCNSL (n=9). Seven patients had concomitant involvement of the cerebrospinal fluid (CSF). Patients were included either for a relapse after last treatment (80 %; median time to relapse = 5.5 months), or for a refractory disease (20 %). Thirty-four patients received concomitant corticosteroids during the first month of treatment. Forty-five patients were evaluable for response after the first cycle of treatment. Median number of induction cycles was 7 (range, 1-8). Grade 3 or 4 adverse events were reported in 11 patients (infection: n = 10, cutaneous rash: n =1). A second cancer (melanoma) occurred in one patient. Two patients withdrew their consent. During the induction phase, best observed responses were CR (n = 16), PR (n = 11), stable disease (n = 5) and progressive disease (n = 11) for an ORR of 63% (27/43). . At the end of the induction phase, 43 patients were evaluable for the primary objective. ORR was 39 % (17/43) including 13 CR (30%). A response has been observed in patients included for a PCNSL (n = 13, 32%) and for an IO relapse or PVRL (n = 4, 44%). Seventeen patients started the maintenance phase. With a median follow-up of 9 months (range, 1.1-15.4), median overall and progression-free survivals of the whole population were 15.3 months (95 % CI, 9.6 - non reached) and 8.1 months (95 % CI, 4.2 - non reached) respectively. Median duration of response in the responder patients was 8.9 months (95 % CI, 7.6- non reached). The results of the maintenance phase are pending. Results will be further updated.ConclusionThis phase II study demonstrates a significant activity of the rituximab-lenalidomide regimen in relapse or refractory PCNSL or PVRL. Updated results with a longer follow-up are awaited to better evaluate the PFS and the median duration of response. This regimen warrants to be added in the armamentarium drugs for PCNSL and further explored in combination with other chemotherapies in first-line treatment, as maintenance therapy, or as a chemo-free regimen for patients unfit for high-dose methotrexate.Funding: Celgne, Roche [Display omitted] DisclosuresGhesquieres:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche France: Research Funding; Mundipharma: Consultancy. Choquet:Celgene: Consultancy; Janssen: Consultancy. Morschhauser:Celgene: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Gilead Sciences: Consultancy, Honoraria; Janssen: Honoraria; Servier: Consultancy, Honoraria. Soussain:Roche: Research Funding; Pharmacyclics: Research Funding; Celgene: Research Funding.

Ibrutinib Monotherapy in Relapse or Refractory Primary CNS Lymphoma (PCNSL) and Primary Vitreo-Retinal Lymphoma (PVRL). Result of the Interim Analysis of the iLOC Phase II Study from the Lysa and the French LOC Network

RATIONALPrimary CNS lymphoma (PCNSL) is a diffuse large B-cell lymphoma (DLBCL), predominantly of non-germinal center (non-GC) subtype, carrying a pejorative prognosis. Constitutive activation of the NF-kB pathway via mutations in B cell receptor (BCR) pathway (CD79B) and mutation of MYD 88 and TBL1XR1 plays an important role in PCNSL. Ibrutinib, an inhibitor of BCR signaling, has been found to have significant therapeutic activity in relapsed or refractory non-CNS non-GC DLBCL.METHODSIn this prospective, multicenter, open-label phase II, we enrolled immuno-competent patients over 18 with a refractory or relapse of PCNSL or primary vitreo-retinal lymphoma (PVRL) of DLBCL type. The treatment consisted in ibrutinib monotherapy given orally at 560 mg daily until disease progression or unacceptable toxicity. Additional corticosteroids treatment was allowed during the first 4 weeks of treatment in case of a threatening or symptomatic edema. Therapeutic responses were assessed according to the international primary CNS lymphoma collaborative group (IPCG) criteria. The primary objective of the study was the disease control (DC) rate (CR + CRu + PR + SD) after two months of treatment. This study is a two-stage Simon’s design. Patients were evaluable for response if they received > 90 % of the expected dose during the first month of treatment. An interim analysis for futility was planned when 18 patients were evaluable for response. P0 and P1 hypotheses were < 10 % and > 30 % respectively. A total of 35 evaluable patients are required for the final analysis. Exploratory ancillary studies are planned and consist in dosage of ibrutinib in the cerebrospinal fluid after one cycle of treatment, and correlation of therapeutic response with mutational status of the disease. This study is registered with ClinicalTrials.gov, number NCT02542514.RESULTSBetweenSeptember 25, 2015 and June 30, 2016, 52 patients were recruited in 10 French centers of the French LOC network for PCNSL. The interim analysis was done on the first 18 patients evaluable for response (median age: 70 y, range 49-80). At initial diagnosis, diagnoses were PCNSL (n = 12) and PVRL (n = 6). Patients were included in the study for a relapse (n = 13) or a progressive disease (n = 5). At time of inclusion in the study, disease status was PCNSL (n = 11) and PVRL or isolated intra-ocular relapse of a PCNSL (n = 7). ECOG performance status was 0, 1 and 2 in 4, 10 and 4 patients respectively. All the patients had previously received high-dose methotrexate-based chemotherapy. Four patients had previously received high-dose chemotherapy followed by autologous stem cell transplantation. Patients had received 1, 2 or 3 prior treatments in 12, 5 and 1 cases respectively. Three patients had a concomitant meningeal involvement. Five patients received concomitant corticosteroids during the first month of treatment. At the time of analysis (median follow-up = 6.6 months), nine patients discontinued ibrutinib after a median duration of 3 months (range, 0.9 -6.4) because of a disease progressive(n = 8) or a concurrent illness (n=1). Median number of treatment cycles was 5 (range, 1-9). One patient experienced a pulmonary aspergillosis with a favorable outcome. No hemorrhagic complication was reported. Five patients died due to disease progression (n = 4), and concurrent illness (n = 1). After two months of treatment, a DC was achieved in 15/18 patients (83 %, IC 95 %, [59-96%]) (complete and unconfirmed complete response: n =3; partial response: n = 7; stable disease: n =5).CONCLUSIONIn this interim analysis, Ibrutinib monotherapy demonstrated a high DC rate of 83%, including 56% objective responses in patients with relapse/refractory PCNSL or PVRL. Regarding safety, Ibrutinib might be a risk factor for aspergillosis in this population of PCNSL patients, otherwise not exposed to fungal infection. A security warning was sent to all the investigators for a close monitoring of infections. The second cohort of patients has been recruited. Thirty-three patients are currently on study treatment. The final analysis of the iLOC study is awaited to confirm these encouraging results and better define the positioning of ibrutinib in the therapeutic strategy of PCNSL and PVR patients. DisclosuresChoquet:Janssen: Consultancy; Celgene: Consultancy. Ghesquieres:Mundipharma: Consultancy; Roche France: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees. Soussain:Celgene: Research Funding; Roche: Research Funding; Pharmacyclics: Research Funding.

Determining protein biomarkers for DLBCL using FFPE tissues from HIV negative and HIV positive patients.

DLBCL is the most common lymphoma subtype occurring in older populations as well as in younger HIV infected patients. The current treatment options for DLBCL are effective for most patients yet the relapse rate is high. While many biomarkers for DLBCL exist, they are not in clinical use due to low sensitivity and specificity. In addition, these biomarkers have not been studied in the HIV context. Therefore, the identification of new biomarkers for HIV negative and HIV positive DLBCL, may lead to a better understanding of the disease pathology and better therapeutic design. Protein biomarkers for DLBCL were determined using MALDI imaging mass spectrometry (IMS) and characterised using LC-MS. The expression of one of the biomarkers, heat shock protein (Hsp) 70, was confirmed on a separate cohort of samples using immunohistochemistry. The biomarkers identified in the study consisted of four protein clusters including glycolytic enzymes, ribosomal proteins, histones and collagen. These proteins could differentiate between control and tumour tissue, and the DLBCL immunohistochemical subtypes in both cohorts. The majority (41/52) of samples in the confirmation cohort were negative for Hsp70 expression. The HIV positive DLBCL cases had a higher percentage of cases expressing Hsp70 than their HIV negative counterparts. The non-GC subtype also frequently overexpressed Hsp70, confirming MALDI IMS data. The expression of Hsp70 did not correlate with survival in both the HIV negative and HIV positive cohort. This study identified potential biomarkers for HIV negative and HIV positive DLBCL from FFPE tissue sections. These may be used as diagnostic and prognostic markers complementary to current clinical management programmes for DLBCL.

CARMA1- and MyD88-dependent activation of Jun/ATF-type AP-1 complexes is a hallmark of ABC diffuse large B-cell lymphomas

AbstractA hallmark of the diffuse large B-cell lymphoma (DLBCL) of the activated B-cell (ABC) type, a molecular subtype characterized by adverse outcome, is constitutive activation of the transcription factor nuclear factor–κB (NF-κB), which controls expression of genes promoting cellular survival and proliferation. Much less, however, is known about the role of the transcription factor activator protein-1 (AP-1) in ABC DLBCL. Here, we show that AP-1, like NF-κB, was controlled by constitutive activation of the B-cell receptor signaling component caspase recruitment domain-containing membrane-associated guanylate kinase 1 (CARMA1) and/or the Toll-like receptor signaling component myeloid differentiation primary response gene 88 (MyD88) in ABC DLBCL cell lines. In contrast to germinal center (GC) B-cell (GCB) DLBCL, ABC DLBCL cell lines expressed high levels of the AP-1 family members c-Jun, JunB, and JunD, which formed heterodimeric complexes with the AP-1 family members activating transcription factor (ATF) 2, ATF3, and ATF7. Inhibition of these complexes by a dominant-negative approach led to impaired growth of a majority of ABC DLBCL cell lines. Individual silencing of c-Jun, ATF2, or ATF3 decreased cellular survival and revealed c-Jun/ATF2-dependent control of ATF3 expression. As a consequence, ATF3 expression was much higher in ABC vs GCB DLBCL cell lines. Samples derived from DLBCL patients showed a clear trend toward high and nuclear ATF3 expression in nodal DLBCL of the non-GC or ABC subtype. These findings identify the activation of AP-1 complexes of the Jun/ATF-type as an important element controlling the growth of ABC DLBCL.