ALBERT

Description: The mutational landscape of grey zone lymphoma (GZL) has not yet been established and differences to related entities are largely unknown. Here, we studied coding sequence mutations of 50 EBV-negative GZL and 20 polymorphic EBV-positive DLBCL NOS (poly-EBV-L) in comparison to classical Hodgkin lymphoma (cHL), primary mediastinal large B cell lymphoma (PMBCL), and diffuse large B cell lymphoma (DLBCL). Exomes of 21 GZL and 7 poly-EBV-L cases along with paired normals were analyzed as a discovery cohort followed by targeted sequencing of 217 genes in an extension cohort of 29 GZL and 13 poly-EBV-L cases. GZL cases with thymic niche involvement (anterior mediastinal mass) displayed a mutation profile closely resembling cHL and PMBCL, with SOCS1 (45%), B2M (45%), TNFAIP3 (35%), GNA13 (35%), LRRN3 (32%) and NFKBIA (29%) being the most recurrently mutated genes. In contrast, GZL cases without thymic niche involvement (N=18) had a significantly distinct pattern, enriched in mutations related to apoptosis defects (TP53 (39%), BCL2 (28%), BIRC6 (22%)) and depleted in GNA13, XPO1or NFKB signaling pathway mutations (TNFAIP3, NFKBIE, IKBKB, NFKBIA). They also presented more BCL2/BCL6 rearrangements as opposed to thymic GZL. Poly-EBV-L cases presented a distinct mutational profile including STAT3 mutations and a significantly lower coding-mutation load in comparison to EBV-negative GZL. Our study highlights characteristic mutational patterns in GZL associated with presentation in the thymic niche suggesting a common cell of origin with disease evolution overlapping with related anterior mediastinal lymphomas.

Description: Introduction Mantle-cell lymphoma (MCL) is of poor prognosis, with a median survival of about 5 years. Besides the t(11;14) translocation, several secondary genetic abnormalities have been shown to correlate with prognosis. However, most studies have analysed patients with heterogeneous treatment, mostly with anthracyclin-based regimens. In 2004, the European MCL Network started the randomized MCL Younger trial comparing R-CHOP followed by high-dose radiochemotherapy and autologous stem cell transplantation (ASCT) versus alternating R-CHOP/R-DHAP followed by a high-dose cytarabine conditioning regimen and ASCT in previously untreated MCL stage II-IV patients up to the age of 65y. The R-CHOP/R-DHAP arm showed improved time to treatment failure (TTF) and, potentially, overall survival (OS) (Hermine et al., ASH 2010, ASH 2012). Our aim was to revisit the prognostic value of some gene copy number alterations (GCNA) in this randomized trial and to determine whether high-dose cytarabine could counteract some of those factors. Methods The inclusion criteria for this biological study were: confirmed histological diagnosis of MCL, the availability of diagnostic tumor DNA and complete clinical data. When no frozen biopsy was available, peripheral samples with more than 50% tumor cells were considered eligible for GCNA analysis. CDKN1B, CDK2, and MDM2 were analyzed using quantitative multiplex PCR of short fluorescent fragments (QMPSF) (Jardin et al., BJH 2009), 6q25-q26, CDK4, and the 13q14 locus were analyzed by multiplex ligation-dependent probe amplification (MLPA) (MRC-Holland CLL kit), and MYC, CDKN2A, ATM, RB1 and TP53 were assessed by both methods. The analyses of the prognostic value of GCNA was adjusted for clinical prognostic factors summarized in the quantitative MIPI score (age, performance status, LDH, and WBC). The rate of proliferating tumor cells (Ki-67 index) was centrally assessed by the reference pathologists of the European MCL Pathology Panel according to published guidelines (Klapper et al., J Hematopathol 2009). Outcome variables were TTF from treatment start to stable disease, progression, or death from any cause, and OS from trial registration to death from any cause. Results Of 135 patients fulfilling the inclusion criteria (median age 56 years), 49%, 26%, and 25% of patients were of low, intermediate, and high MIPI risk . The most frequent amplification involved MYC (18%), whereas the most frequent deletion involved the 13q14 locus (36%), including RB1 in 26%. As expected, CDKN2A and TP53 deletions were frequently found (25% and 22%, respectively). ATM alterations mostly consist of deletion (25%), but amplification was found in 3 of 129patients. The frequencies of GCNA did not differ according to the type of sample analyzed i.e. tumor biopsies (n=79) vs. high tumor load peripheral blood or bone marrow samples (n=56). The Ki-67 index was higher in patients with CDKN2A or RB1 deletion compared to patients without, but was not different between patients with or without TP53 deletion. Only TP53 gene status was associated with MCL cytology, with more frequent deletion in blastoid forms (4/8) than in classic MCL (11/81, 14%). In univariable analyses, deletions of CDKN2A, 13q14, RB1, CDKN1B, and TP53 were associated with shorter TTF and OS, whereas GCNA of 6q25-q26, MYC, ATM, CDK2, CDK4, and MDM2 were not prognostic. In multivariable analyses, adjusting for MIPI score, CDKN2A and TP53 deletions showed independent prognostic impact with hazard ratios of 2.4 (p=0.001) and 2.3 (p=0.004) for TTF and 2.3 (p=0.007) and 2.4 (p=0.007) for OS. This effect was observed in both treatment arms (Figure 1). In addition, there was an interacting effect of CDKN2A (p16) deletion and TP53 deletion on TTF (p=0.004). Conclusions The introduction of high-dose cytarabine in first-line treatment of younger MCL patients did not erase the adverse prognostic value of TP53 and CDKN2A deletions observed with previous regimens. Moreover, our study identified a small patient group of very bad prognosis which could benefit of more aggressive regimens or new targeted drugs combination. Figure 1: TTF (left) and OS (right) according to CDKN2A/TP53 deletion status in patients of the R-CHOP/R-DHAP study arm; nom=not deleted, del=deleted Figure 1:. TTF (left) and OS (right) according to CDKN2A/TP53 deletion status in patients of the R-CHOP/R-DHAP study arm; nom=not deleted, del=deleted Figure 2 Figure 2. Disclosures Feugier: Roche: Honoraria. Haioun:Roche, Celgene, Takeda, Pfizer, Janssen,: Honoraria.

Description: Abstract 1617 Background: Romidepsin is a selective class 1 histone deacetylase inhibitor approved by the FDA for patients with cutaneous T-cell lymphoma and PTCL who have received at least 1 prior therapy. In recurrent/refractory PTCL, it has been evaluated as a single agent in 2 phase II studies with overall response rates of 25–38% (Piekarz, Blood 2011;117:5827; Coiffier, J Clin Oncol 2012;30:631). Toxicity was mainly hematologic and digestive. The aim of the present study was to evaluate the safety, tolerability and efficacy of different doses of romidepsin in association with CHOP in patients with previously untreated PTCL. Methods: Patients with biopsy-proven PTCL were planned to receive 8 cycles of CHOP (cyclophosphamide 750 mg/m2 day 1, doxorubicin 50 mg/m2 day 1, vincristine 1,4 mg/m2 day 1, prednisone 40 mg/m2 days 1 – 5) in association with varying doses of romidepsin. Based on pharmacokinetic data and results of previous phase II studies, the starting dose of 10 mg/m2 on days 1 & 8 was chosen. The dose-variation scheme follows a traditional “3+3” design. Dose-limiting toxicity (DLT) were considered during the first 2 cycles. Results: Eighteen patients (11 male, 7 female, aged 31 to 78) have been included and are analyzable for toxicity during the first two cycles. Diagnoses were: PTCL, not otherwise specified (n=10), angioimmunoblastic TCL (n=4), other PTCL (n=4). ECOG performance status was good (0–1) in all but one patient; 17/18 had stage III-IV disease; LDH levels were elevated in 11/18. The age-adjusted IPI score was 0 (n=1), 1 (n=14), 2 (n=3). Significant, albeit tolerable haematological toxicity having been observed in the first two cohorts, the definition of DLT was modified during the course of the study. The study diagram is shown in the figure. Accrual of the phase Ib part of the study is now completed and the phase II part is ongoing with a dose of 12 mg/m2 D1&8. Serious adverse events of interest included: One episode of acute pulmonary edema after course 1 in 1 patient, acute coronary syndrome (n=1), deep venous thrombosis (n=1) and cardiac arrhythmia (n=1). Among 14 evaluable patients, 3 progressed during treatment or shortly after end of treatment; and 11 responded (partial response 3/14, complete response 8/14) for an overall response rate of 78%. The 4 other patients have not yet reached the 8 cycles. Conclusion: Romidepsin can be combined with CHOP at the price of foreseeable hematological toxicity. Some cardiovascular events have been observed but the relationship with romidepsin is questionable. The dose of 12 mg/m2 on days 1& 8 is currently evaluated in the phase 2 part of the study. Response rates seem promising, but longer follow-up is needed. Updated results will be presented at the meeting. Disclosures: Ribrag: Servier: Membership on an entity's Board of Directors or advisory committees, Research Funding; astrazeneca: Membership on an entity's Board of Directors or advisory committees; takeda: Membership on an entity's Board of Directors or advisory committees; bayer: Research Funding; sanofi: Research Funding. Coiffier:Celgene: Consultancy.

Description: Abstract 2632 Hans algorithm using immunohistochemistry correlates well with gene expression data in Diffuse large B-cell lymphomas (DLBCL) (Meyer PN, 2011) and has demonstrated in some studies clear survival differences in favor of germinal-centre (GC) vs non-germinal centre (n-GC) B-cell among DLBCL treated with R-CHOP. We undertook an immunohistochemical study among patients aged 18 to 59 years with aaIPI 1 included in the GELA trial LNH 03-2B that compared R-ACVBP intensified immunochemotherapy to standard R-CHOP. This trial demonstrated an improvement of EFS, PFS and overall survival (OS) of patients treated with R-ACVBP (C Recher et al, in press). Our goal was to evaluate survival of patients with GC and n-GC DLBCL according to treatment regimens. We analyzed by immunohistochemistry the expression of CD10, BCL6 and MUM1 and classified patients as GC or n-GC according to the Hans algorithm. Among the 380 patients enrolled in this study, 229 patients were available for Hans algorithm classification. There was no differences considering clinical characteristics of these 229 patients (age, sex, B symptoms, PS, Stage, LDH, number of extranodal sites, bulky mass, bone marrow involvement) compared to the whole LNH03-2B population. 175 DLBCL cases were present on a tissue microarray (TMA) and 54 other cases were analyzed using unstained slides. 101 patients were classified as GC and 128 as n-GC. 107 patients were treated by R-ACVBP and 122 by R-CHOP. EFS, PFS and OS were not different between the GC and n-GC profile among the whole population (P=.82, P=.90, P=.68, respectively). There was no statistical difference in EFS, PFS and OS between R-ACVBP and R-CHOP in GC patients (P=.78; P=.84, P=.33, respectively). Interestingly, EFS, PFS and OS were significantly much longer among n-GC patients treated by R-ACVBP compared to R-CHOP (P=.02; P=.007, P=.007, respectively). Results were similar considering only TMA population (P=.02, P=.001, P=.001, respectively). This subgroup analysis suggests that the survival benefit related to R-ACVBP over R-CHOP in the LNH 03-2B is in large part linked to a survival improvement in the n-GC population. This algorithm, easy to apply on routine paraffin-embedded tissue, might be useful in the future to select patients that can primarily benefit from this intensive regimen. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 90 Background: rituximab had dramatically improved the prognosis of patients with Diffuse Large B-cell Lymphoma (DLBCL) in combination with chemotherapy. Many biological and clinical studies suggested considerable inter-individual variability in term of anti-CD20 monoclonal antibody (mAb) activity with tumor and host-related influencing factors. Among host-related factors, the presence of functional polymorphisms in FcG receptors genes as FCGR3A-158V/F influences the affinity for IgG1 and consequently the antibody dependant cellular cytotoxicity (ADCC) with therapeutic mAbs such as rituximab. The clinical consequence reported to date consists in a better response rate to rituximab monotherapy for FCGR3A-158V homozygous patients treated for follicular lymphoma compared FCGR3A-158F carriers. In DLBCL and in the context of combination with chemotherapy, the role of FCGR3A and FCGR2A SNPs on treatment response and patient's outcome is not clear with few prospective studies. The aim of this study is to determine the impact of FCGR3A and FCGR2A SNPs on response and outcome of newly diagnosed DLBCL patients included in the prospective trials of the GELA (LNH2003 program). Patients and Methods: 1564 patients from France, Switzerland and Belgium were included in the 5 prospective multicentric trials of the LNH2003 program of the GELA designed for DLBCL patients who were stratified in different subgroups based on age and International Prognostic Index (IPI) score. A sample of peripheral blood lymphocytes was collected before treatment from 760 patients who signed a specific consent form for this genetic study. After pathologic review and exclusion of patients not receiving rituximab (48 patients), 554 DLBCL patients were available for this study. SNPs were genotyped using a TaqMan® based assay. Results: The median age of the 554 patients was 61 years (range, 18–93 years), 57% of them were male and 50% of patients presented at diagnosis a 2–3 age-adjusted IPI score. Chemotherapy regimen consisted in a combination of rituximab with CHOP-21 (110 patients, 20%), CHOP-14 (181 patients, 33%), low dose CHOP for patients older than 80 years (60 patients, 11%), or ACVBP regimen (203 patients, 36%). At the end of treatment, complete response (CR) or unconfirmed CR was observed in 75% of patients. After a median follow-up of 38 months, the 3-year progression free survival (PFS) and overall survival (OS) was 70.2% and 75.7%, respectively. The distribution of the VV, VF and FF FCGR3A alleles was 14.8%, 46.4%, 38.8%, and 27.8%, 48.6%, 23.6% for HH, HR and RR FCGR2A alleles, respectively, and were therefore consistent with Hardy-Weinberg equilibrium. Initial clinical characteristics of patients (age, sex, Performance Status, stage, B-symptoms, number of extra-nodal sites, LDH level, IPI) were not different according to the two FCGR SNPs. CR/CRu after induction therapy was observed in 61%, 66%, 61% for VV, VF and FF carriers (P = .46) and 60%, 64%, 64% for HH, HR and RR carriers (P =.70), respectively. No difference of response after consolidation treatment was observed between each genotype of FCGR3A and FCGR2A SNPs. The 3-year PFS was 65.3%, 71.4%, 70.5% for FCGR3A VV, VF and FF carriers (P = .43) and 69.2%, 67.6%, 76.6% for FCGR2A HH, HR, RR carriers (P =.09), respectively. The 3-year OS was also not different between the three genotypes of each FCGR SNPs. Conclusions: To our knowledge, this is the largest prospective multicentric study that investigates the role of FCGR2A and FCGR3A SNPs on treatment response and outcome in a large series representing the whole spectrum of DLBCL patients. Based on these results, modification of rituximab schedule according to the FCGR3A and FCGR2A genotypes does not appear worth investigating. Others host-related factors influencing the efficiency of immunotherapy need to be investigate. Disclosures: No relevant conflicts of interest to declare.

Description: BACKGROUND: the combination of rituximab (RTX) and lenalidomide (LEN) has been shown to be synergistic in pre-clinical models and in patients (pts) with previously untreated and relapsed follicular lymphoma (FL). Furthermore, LEN demonstrated single agent efficacy in pts with mantle cell lymphoma (MCL) and diffuse large B cell lymphoma (DLBCL). We hypothesized that the combination of obinutuzumab (GA), a glycoengineered type II anti-CD20 antibody, with LEN (GALEN) might be even more efficient while retaining a similarly manageable safety profile. In 2012, we started a phase Ib/II study to assess the safety and efficacy of this combination (ClinicalTrials.gov: NCT01582776) in pts with relapsed/refractory lymphoma. Phase IB defined the recommended dose (RD) of LEN as being 20mg in combination with GA. Here, we report the results of the Phase II part assessing efficacy and safety of GALEN therapy during a 6 months induction followed, for responders, by a reduced LEN maintenance GALEN regimen (in a cohort of relapsed/refractory aggressive NHL (DLBCL or MCL) pts. METHODS: pts with a histologically confirmed DLBCL (de novo or transformed low-grade NHL) or MCL were eligible if they had a ECOG PS of ²2, a life expectancy 〉3 months (mo) and had previously received ³1 prior therapy including at least one RTX-containing regimen. Induction treatment consisted of LEN 20 mg given orally once daily on days 1-21 of a 28-day cycle for the first cycle and on days 2-22 of a 28-day cycle from cycles 2 to 6. Intravenous infusions of GA were given at a flat dose of 1000mg on days 8, 15, and 22 of cycle 1 and at D1 of cycles 2 to 6 (total of 8 infusions). Responding pts then received 12 cycles of LEN at 10 mg daily on days 2-22 every 28 days for a total of 18 cycles and GA 1000mg every 8 weeks for 12 additional cycles until progression or unacceptable toxicity. All pts were required to take daily aspirin (100 mg) for deep vein thrombosis (DVT) prophylaxis during study period. Pts who were unable to tolerate aspirin and had a prior history of DVT or were at high risk for a DVT received low molecular weight heparin therapy or warfarin (coumadin) treatment. The primary study endpoint was overall response rate (ORR) by investigator assessment at the end of induction according to 1999 IWG criteria. Secondary endpoints included ORR and complete response (CR) according to IWG 2007, best ORR, duration of response, progression-free survival, overall survival (OS) and safety. RESULTS: ninety-one pts (DLBCL [n=77 including 18 transformed], MCL [n=13], and other [n=1]) were enrolled between June 2014 and March 2015 at 22 LYSA centers in France and Belgium. At baseline, median age was 70 (range, 48-84) years with 64.7% men, ECOG PS of 1 (47.1%) or 2 (18.8%), 83.5% Ann Arbor stage III-IV and 66.3% with elevated LDH. Median number of prior systemic therapies was 2 (range, 1-9) including haematopoietic stem cell transplantation in 17pts (20%); 61% were refractory to a RTX-containing regimen and 53% refractory to last prior therapy. Three pts were withdrawn before receiving any treatment due to major protocol violation, concurrent illness or ulceration of the tumor in the stomach and 3 pts received one of both study drugs, leaving 85 pts assessable for efficacy. Cut-off date was March 25th 2016. With amedianfollow-up of 14.5 mo,39pts (45.8%) completed induction (32 DLBCL and 7 MCL) and 20 (23.5%) are still ongoing in maintenance (16 DLBCL, 4 MCL). At the time of the cut-off, 44pts (51.8%) had died mainly due to lymphoma (88.6%). Response at the end of induction, best ORR during induction and OS are summarized in the table. Table Analysis of other secondary endpoints and correlation with cell of origin is ongoing. The most common treatment emergent AEs during induction (all grades 〉10%pts/ % grade 3/4) were neutropenia (51.1/31.8), infections (45.5/12.5), constipation (30.7/0.0), cough (21.6/1.1), diarrhea (17.0/3.4), nausea (17.0/0) anemia (15.9/10.2), thrombocytopenia (15.9/10.2), muscle spasms (13.6/0.0), fatigue (12.5/1.1) and dyspnea (11.4/4.5). Febrile neutropenia occurred in 4.5% pts. There was onlyone secondprimary malignancy (basal carcinoma). CONCLUSION: oral LEN plus GA infusion is effective in relapsed or refractory DLBCL and MCL pts with no unexpected toxicity. Longer follow-up and additional translational studies are needed to identify the subset of pts most benefiting of this regimen. Correlative studies will be presented at the meeting. Table Table. Disclosures Morschhauser: celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; servier: Consultancy, Honoraria; gilead: Consultancy, Honoraria; janssen: Honoraria. Cartron:Roche: Consultancy, Honoraria; Celgene: Honoraria; Gilead: Honoraria; Jansen: Honoraria. Salles:Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Gilead: Honoraria, Research Funding; Mundipharma: Honoraria; Novartis: Consultancy, Honoraria; Roche/Genentech: Consultancy, Honoraria, Research Funding. Maerevoet:ARGN-X: Membership on an entity's Board of Directors or advisory committees; roche: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. Bonnet:ROCHE: Membership on an entity's Board of Directors or advisory committees; SERVIER: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; JANSSEN: Membership on an entity's Board of Directors or advisory committees.

Description: Background. R-CHOP is the standard first-line treatment for elderly patients with diffuse large B-cell lymphoma (DLBCL). However 30% of patients will relapse and 70% of relapsed patients will die within 2 years of diagnosis. The REMARC study (clinicalTrials.gov NCT01122472) is an international, multicenter, double-blind, randomized, placebo controlled, phase III trial that assessed the benefit of lenalidomide (LEN) maintenance after response to R-CHOP in patients aged 60 to 80 years with untreated DLBCL, FL3b or transformed lymphoma. Patients achieving CR or PR at the end of 6 or 8 cycles of R-CHOP21 or R-CHOP14 were stratified by CR/PR status and country and randomized 1:1 to receive 2 years of LEN maintenance (25 mg/day for 21 of every 28 days) or placebo (PBO). The primary endpoint of the study was progression-free survival (PFS). Secondary endpoints were safety, PR to CR conversion rate, and overall survival (OS). Diagnosis was retrospectively centrally reviewed. In patients with adequate samples, GCB/nonGCB profile was assessed by the Hans algorithm and GCB/ABC/unclassified profile was assessed using NanoString gene expression profiling technology. Methods. From 05/2009 to 05/2014, 784 patients were enrolled either before R-CHOP (n= 437) or after completion of 6 or 8 cycles of R-CHOP (n= 347). At the end of R-CHOP therapy, 650 patients were randomized to maintenance, either in CR (n= 495) or in PR (n= 152). Central review found that 3 patients were randomized in SD or PD, all in LEN arm. At time of diagnosis, median age was 68 y (range 58-80), 43.5% were older than 70 y, and 56% were male. aaIPI was low in 38.5% and high in 57.5% of patients (missing data 4%). COO analyses are ongoing for both Hans algorithm and NanoString technology. Results. With a median follow-up of 40 months, median PFS (according to independent centralized radiology review) was not reached in the LEN group versus 68 months in the PBO group (hazard ratio favoring the LEN group, 0.708 (95% CI 0.537-0.932; p=0.0135))(See Figure). In the LEN group, 18 patients (21%) converted from PR to CR during maintenance compared to 13 patients (14%) in the PBO group. Immature overall survival data did not show any benefit for LEN arm, a lack of difference not attributable to an excess of lymphoma relapse, secondary cancer or safety problems in LEN arm. Deaths generally occurred off study drug (median time from last dose of study drug to death was 277 days (range 20, 1291) in LEN arm and 334 (41, 1594) in control arm. During maintenance, the most common observed grade 3 or 4 AEs were neutropenia (56% vs. 22%), rash (5% vs. 1%), infections (8% vs. 6%), and thrombocytopenia (2.5% vs. 0.6%) in LEN and PBO arms, respectively. Dose adjustments were necessary in 72% of the LEN patients and 42% of PBO patients. 59% of patients stopped LEN and 40% stopped PBO for toxicity (p

Description: Abstract 1598 Tumor bulk assessed by maximum tumor diameter was previously found to influence the outcome of young patients with low risk (aaIPI 0–1) DLBCL (Pfreundschuh et al Lancet Oncol, 2011; 12: 1013), but the prognostic impact of bulk and more generally tumor volume in high-risk DLBCL remains to be explored. Conversely, maximum SUV reduction calculated between baseline PET and PET performed after 4 cycles of immunochemotherapy (ΔSUVmax0–4) was recently shown to predict outcome in this population (Casasnovas et al Blood 2011; 118: 37). In this study, we assessed the metabolic tumor volume (MTV) and the tumor bulk at baseline in 121 patients 10 cm assessed on CT scan was considered as bulky. Median follow-up was 28 months. Median baseline MTV was 303 cc (17–1488). Baseline MTV (≥625 cc vs 10 cm was not predictive of outcome. As previously published ΔSUVmax0–4 (〉 70% vs ≤70%) found to predict 2y-PFS (88% vs 40%; p

Description: Abstract 2687 Classical Hodgkin lymphomas (cHL) are B lympho-proliferative disorders that can be cured in 80% of cases. The goal of current research is to identify, at diagnosis, the 20% patients, who are likely to relapse or be refractory to treatment. As cHL have an extensive micro-environment implicated in tumour growth, the prognostic value (disease-free survival) of 2 important subsets of lymphoid cells (CD45RO+ effector memory T cells and FOXP3+ regulatory T cells) of the micro-environment has been evaluated using Tissue Micro Array (TMA). Patients (n=96) treated and followed for cHL between 1998 and 2005 were included in this study. Six TMA with 3 spots per case, were built (3 formalin and 3 Bouin fixative). Immunostaining with anti-CD45RO (Dako, UCHL1, 1/400) and anti-FOXP3 (Abcam, 236A/E7 1/100) antibodies was performed on the Benchmark Ultra (Ventana). After scanning of the slides, the staining was quantified automatically using a function (pixel count) of Scanscope software (Aperio). ROC curves were used in order to calculate the best threshold for each marker, depending on the number and intensity of pixels. Survival curves were built according to these thresholds using the Kaplan Meier method and compared with the log-rank test. Then, a Cox model was used to estimate the risk of occurrence of an event in univariate and multivariate analyses. The demographic characteristics of patients and sub-types of HL were not different in the 〉 and 〉 groups. Median follow-up of patients was 69 months (1-135). In univariate analysis, low quantities of CD45RO+ cells was associated to a 40% 5-years progression free survival (PFS) compared to a 87% 5-years PFS for patients with high number of CD45RO+ cells (p=0.003), and low number of FOXP3+ cells was related to a 56% 5-years PFS compared to a 86% 5-years PFS for patients with high number of FOXP3+ cells (p=0.026). In multivariate analysis, taking into account the International Prognostic Score (IPS) and the expression of CD15 by neoplastic cells, the association of CD45RO and FOXP3 was the only independent prognostic factor identified (p

Description: Background CD20 is a cell surface antigen commonly expressed on B-cell lineage, but is absent on hematopoïetic stem cells and plasma cells. Therefore, it has been postulated that its targeting should not significantly affect immunoglobulin serum concentrations. However, due to rapid and prolonged B-cell depletion, rituximab-based therapy has been shown to impair humoral response. In addition, protective serologic response to influenza vaccination in lymphoma patients in the 6 months following rituximab-containing regimen has been found to be particularly low1. Because the vast majority of adults individuals have been previously vaccinated against tetanus, we decided to analyse the impact of prolonged rituximab-based therapy on the immune protection rate against tetanus toxin in patients, and conducted in this aim a sub-analysis in follicular lymphoma (FL) patients treated into the PRIMA study. Methods The PRIMA study is a multicentre, phase III, randomized study in patients with advanced FL evaluating the benefit of maintenance therapy with rituximab after induction of response with chemotherapy plus rituximab in comparison with no maintenance therapy, whose results have been previously published2. In a subset of patients, serum samples were prospectively collected and antitetanus toxin antibodies were measured at baseline, end of immunochemotherapy induction and end of maintenance period. Protective titer was defined as 〉 0.1 UI/mL according to standards. Statistical analysis aimed to determine if serum antitetanus antibodies titers significantly changed over time according to different phases of treatment, and if rituximab maintenance arm had a significant impact as compared to observation arm. Results Overall, 104 patients were evaluable for this subanalysis. Fifty-five percent were male. Median age was 57 (range, 27-80), 88.5% had Ann-Arbor stage III-IV disease. All patients had received R-CHOP induction. Among those patients, 56 were randomised into rituximab arm, 48 into observation arm. At baseline, median serum antitetanus antibodies titers in the overall population was 0.8 UI/mL (range, 0–8) and 89.4% of patients had protective titers. At the end of induction, among the 70 evaluable subjects, 90% had still a protective titer with a median of 0.7 UI/mL (range, 0-4), and at the end of maintenance period, among the 62 evaluable patients, 93% had still protective titer with a median of 0.8 (range, 0-3). When comparing the two arms, at the end of maintenance period, median serum antitetanus antibodies titer was 0.8 UI/mL in the rituximab arm, not significantly different from that in the observation arm (0.6 UI/mL) (p=0.17). At the end of the maintenance period, 100% of subjects had still protective titer in the rituximab arm versus 84.6% in the observation arm. Conclusion In this subanalysis of 104 FL treated patients issued from the PRIMA study, rituximab-based induction and maintenance therapy did not significantly affect the immunisation rate against tetanus toxin in previously immunized patients. These results are in contrast with the poor serologic response rate obtained following rituximab-based therapy, emphasizing that common serum vaccinal titers should be controlled, and vaccination updated, when possible, before treatment initiation and the first rituximab administration. References 1-Yri O, Torfoss D, Hungnes O, et al. Rituximab blocks protective serologic response to influenza A (H1N1) 2009 vaccination in lymphoma patients during or within 6 months after treatment. Blood 2011, 118 (6769 – 6771). 2-Salles G, Seymour J, Offner F, et al. Rituximab maintenance for 2 years in patient with high tumour burden follicular lymphoma responding to rituximab plus chemotherapy (PRIMA): a phase 3, randomised controlled trial. Lancet 2011, 377 (42-51). Disclosures Karlin: Sandoz: Consultancy; celgene: Consultancy, Honoraria; Janssen: Honoraria. Delmer:Roche: Honoraria. Brice:Seattle Genetics, Inc.: Research Funding; Takeda Pharmaceuticals International Co.: Honoraria, Research Funding; Roche: Honoraria.