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Minimal residual disease (MRD) analysis is a known predictive tool in mantle cell lymphoma (MCL). We describe MRD results from the Fondazione Italiana Linfomi phase 3 MCL0208 prospective clinical trial assessing lenalidomide (LEN) maintenance vs observation after autologous stem cell transplantation (ASCT) in the first prospective comprehensive analysis of different techniques, molecular markers, and tissues (peripheral blood [PB] and bone marrow [BM]), taken at well-defined time points. Among the 300 patients enrolled, a molecular marker was identified in 250 (83%), allowing us to analyze 234 patients and 4351 analytical findings from 10 time points. ASCT induced high rates of molecular remission (91% in PB and 83% in BM, by quantitative real-time polymerase chain reaction [RQ-PCR]). Nevertheless, the number of patients with persistent clinical and molecular remission decreased over time in both arms (up to 30% after 36 months). MRD predicted early progression and long-term outcome, particularly from 6 months after ASCT (6-month time to progression [TTP] hazard ratio [HR], 3.83; P < .001). In single-timepoint analysis, BM outperformed PB, and RQ-PCR was more reliable, while nested PCR appeared applicable to a larger number of patients (234 vs 176). To improve MRD performance, we developed a time-varying kinetic model based on regularly updated MRD results and the MIPI (Mantle Cell Lymphoma International Prognostic Index), showing an area under the ROC (Receiver Operating Characteristic) curve (AUROC) of up to 0.87 using BM. Most notably, PB reached an AUROC of up to 0.81; with kinetic analysis, it was comparable to BM in performance. MRD is a powerful predictor over the entire natural history of MCL and is suitable for models with a continuous adaptation of patient risk. The study can be found in EudraCT N. 2009-012807-25 (https://eudract.ema.europa.eu/).

Rituximab (R) is increasingly incorporated in reduced intensity conditioning (RIC) regimens for allogeneic hematopoietic cell transplantation (alloHCT) in patients with B-cell malignancies, not only to improve disease control, but also to prevent graft-versus-host disease (GVHD). There are no randomized prospective data to validate this practice, although single center data and the CIBMTR analysis have shown promising results. We aimed at validation of these findings in a large registry study. We conducted a retrospective analysis using the EBMT registry of 3,803 adult patients with B-cell malignancies undergoing alloHCT (2001-2013) with either rituximab (R-RIC-9%) or non-rituximab (RIC-91%) reduced intensity regimens respectively. Median age and median follow up were 55 years (range 19.1-77.3) and 43.2 months (range 0.3-179.8), respectively. There was no difference in transplant outcomes (R-RIC vs RIC), including 1-year overall survival (69.9% vs 70.7%), 1-year disease-free survival (64.4% vs 62.2%), 1-year non-relapse mortality (21% vs 22%), and day-100 incidence of acute GVHD 2-4° (12% vs 12%). In summary, we found that addition of rituximab in RIC regimens for B-cell malignancies had no significant impact on major transplant outcome variables. Of note, data on chronic GVHD was not available, limiting the conclusions that can be drawn from the present study. ispartof: FRONTIERS IN IMMUNOLOGY vol:11 ispartof: location:Switzerland status: published

The treatment of chronic lymphocytic leukemia (CLL) has been radically changed in the last years thanks to the targeted therapies, including kinase (i.e. ibrutinib) and BCL2 (i.e. venetoclax) inhibitors. Venetoclax (VEN) in particular is able to obtain undetectable minimal residual disease (uMRD), though only in a proportion of patients (pts) when given as single agent, thus warranting the need of different strategies in those not achieving uMRD. We designed a phase 2 multicenter Italian study where ibrutinib (IBR) is added to VEN based on a MRD-driven strategy aiming at obtaining uMRD and discontinuing both treatments in pts who did not achieve uMRD with VEN mono. Study treatment started with VEN (ramp up to 400 mg/day as per current label) for 12 months. MRD status in peripheral blood (PB) and bone marrow (BM) was evaluated using the 6-color flow cytometry assay recommended by ERIC (CD5/CD81/CD79b/CD19/CD43/CD20). Pts with uMRD in both PB and BM at C12D1 discontinued VEN at C12D28 and entered the follow-up phase. Pts with detectable MRD in PB and/or BM added IBR 420 mg/day starting from C13D1 and continued both drugs up to maximum C24D28, uMRD, progression or unacceptable toxicity (whichever occurs first). After C24D28, pts with detectable MRD and still in response continued IBR alone. The primary endpoint was uMRD4 ( Thirty-eight pts (recruited from Nov 2017 to Jul 2018) fulfilled eligibility and started VEN. Baseline characteristics included: median number of prior therapies 1 (range 1-4) (60.6% previously treated with FCR or FC); del(17p) in 8/33 (24%); TP53 mutations in 10/30 (33%), and unmutated IGHV in 24/30 (80%). At the data cut-off, 35/38 evaluable pts still in the study have reached C24D1, 1 pt discontinued treatment due to myelodisplasia (considered unrelated to study treatment) before C12D1 and 1 pt progressed on VEN monotherapy shortly before that timepoint, 1 evaluation is still missing due to COVID-19 restrictions. At C12D1, uMRD4 in PB was achieved in 19/38 (50%) pts (Figure 1), 17/19 (89.5%) had uMRD4 confirmed in BM. Overall response rate with VEN single-agent was 36/38 (94.7%), 9 CR and 27 PR. As per protocol, the 17 pts (45%) with uMRD4 in PB and BM at C12D1 discontinued VEN at C12D28. Nineteen responsive cases with detectable MRD at C12D1 added IBR to VEN starting from C13D1. The combination of IBR and VEN led to an improved reduction of the depth of MRD in all but 3 pts with 16/19 (84%) achieving uMRD4 in both PB and BM between C16D1 (first MRD assessment after starting IBR) and C24D1, thus stopping both therapies as per protocol. After a median follow-up of 25.4 months (range 6.1-33.5) from treatment initiation, no clinical progression was observed among those discontinuing treatment in uMRD, while MRD4 relapse occurred in 21/33. Median time to MRD4 relapse in those who achieved uMRD at any timepoint and discontinued treatment was 4 months (range 2-13). Twelve pts (6 treated with VEN only) remain uMRD after stopping treatment, with a median observation of 13 months (range 3+-18+) since confirmed uMRD4. Safety data were analyzed in the intention-to-treat cohort (39 pts). No cases of clinical tumor lysis syndrome (TLS) and/or biochemical TLS were reported in the 39 pts exposed to VEN. Adverse events (AEs) were mild, with no treatment discontinuations or dose reductions. Five Serious AEs (Table 1) and 130 AEs (Table 2) occurred in 28 patients, without any SUSARs. All 5 SAEs were deemed unrelated to study drug(s) and 4/5 have resolved without sequelae. In conclusion, we here present the updated results of our study including the combination phase of VEN with IBR. This sequential MRD-guided approach was feasible and led to deeper responses in about 85% of pts not achieving uMRD4 after VEN alone. With this tailored and time-limited strategy 33 out of 38 pts (87%) obtained uMRD4 in PB and BM either after VEN monotherapy or the IBR-VEN combination, indicating we may reach identical depth of response with a personalized intensification and avoid unnecessary drug exposure. Time to clinical progression and response to VEN retreatment in this cohort remain to be established as well as the biological characteristics of those pts with persistent MRD despite the combined treatment. Updated results with further sequential MRD and clinical monitoring after treatment discontinuation will be presented at the meeting. Disclosures Scarfo: Gilead: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Farina:Abbvie: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Gaidano:Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astrazeneca: Membership on an entity's Board of Directors or advisory committees; Sunesys: Membership on an entity's Board of Directors or advisory committees. Reda:Janssen: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees. Coscia:Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Shire: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Karyopharm Therapeutics: Research Funding. Laurenti:Roche: Honoraria; Gilead: Honoraria; Janssen: Honoraria; AbbVie: Honoraria. Varettoni:Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Other: Travel/accommodations/expenses; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel/accommodations/expenses. Ghia:Lilly: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Adaptive, Dynamo: Consultancy, Honoraria; MEI: Consultancy, Honoraria; Celgene/Juno: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; BeiGene: Consultancy, Honoraria; Acerta/AstraZeneca: Consultancy, Honoraria; ArQule: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Novartis: Research Funding.

Background and Aims. Prediction of treatment efficacy is an active and growing field of pharmacology. In the Fondazione Italiana Linfomi (FIL) MCL0208 phase III trial (NCT02354313), a 24 months lenalidomide maintenance (LM, 15 mg days 1-21 every 28 days) after high-dose immuno-chemotherapy followed by autologous transplantation (ASCT) in 300 frontline mantle cell lymphoma (MCL) patients showed substantial clinical activity in terms of Progression-Free Survival (PFS) vs observation (OBS). However, this benefit seemed not uniform across patient series. To deeper investigate the differential pattern of response to lenalidomide, a wide analysis of the host pharmacogenomics (PG) background was planned, in order to dissect whether specific germline polymorphisms of transmembrane transporters, metabolic enzymes or cell surface receptors (ABCB1, ABCG2, VEGFA, FCGR2A, NCF4, GSTP1, CRBN) might predict the drug efficacy. Actually, several single nucleotide polymorphisms (SNPs) of ABCB1 exert an effect on substrate affinity of lenalidomide for the transmembrane transporter. Moreover, VEGFA is involved in the anti-angiogenic activity of lenalidomide and might eventually upregulate ABCB1 expression, too. Patients and methods. Genotypes for SNPs were obtained through allele-specific (ASO) probes on germline DNA from peripheral blood. Minor allele frequencies (MAFs) were obtained and the Hardy-Weinberg equilibrium (HWE) was checked. Genotypes were used to infer individual haplotypes by Arlequin and Haploview softwares. Minimal residual disease (MRD) was assessed with ASO primers on either IGH or BCL-1/IGH rearrangements by RQ-PCR in bone marrow samples. TP53 disruption was identified by NGS targeting resequencing and copy number variation analysis. Clinical-biological correlations were screened by automated machine learning methods and validated by both Kaplan-Meier at univariate level and Cox models for multivariate analysis (MV). A logistic regression was implemented to investigate correlations between polymorphisms and MRD kinetics. Results. 278 out of 300 patients (93%) were fully genotyped. The MAF values of the SNPs were very similar to published data and the HWE was confirmed. Most notably, ABCB1 c.2677G>T/A(W) and VEGFA c.2055A>C were significantly associated to outcome and are thus described in this abstract. In the case of ABCB1, the three loci were in strong linkage disequilibrium (p Disclosures Ferrero: Servier: Speakers Bureau; Gilead: Research Funding, Speakers Bureau; EUSA Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Boccomini:SC Ematologia, ASOU Città della Salute e della Scienza di Torino, Turin, Italy: Current Employment. Maria:Roche: Consultancy, Other: travel, accomodations, expenses; Abbvie: Consultancy, Other: travel, accomodations, expenses; BMS: Consultancy; MSD: Consultancy; Janssen: Consultancy, Other: travel, accomodations, expenses; Gilead: Consultancy, Other: travel, accomodations, expenses, Research Funding. Ferreri:Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Morphosys: Research Funding; Hutchinson: Research Funding; BMS: Research Funding. Palumbo:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Galimberti:Novartis: Speakers Bureau; Incyte: Honoraria. OffLabel Disclosure: Lenalidomide maintenance in mantle cell lymphoma

BACKGROUND Allogeneic stem cell transplantation (allo-HSCT) is a treatment option for high-risk multiple myeloma (MM), especially in patients who relapse early following auto-HSCT. Though there is a proven graft versus myeloma effect, relapse remains common. Daratumumab (Dara) is a humanized monoclonal anti-CD38 antibody approved for both newly diagnosed and relapsed MM. Its mechanisms of action include direct anti-MM activity (CDC, ADCC, ADCP, apoptosis induction) and indirect anti-MM activity depleting CD38+ immunosuppressive regulatory cellsand promoting T-cell expansion and activation. The combination of its mechanism of action and lack of toxicity makes Dara a good candidate for use in the post-allo-HSCT setting. However, its immune effects (decrease in CD38-positive immune suppressor cells, including Tregs, NK cells, regulatory B cells, and myeloid-derived suppressor cells) may interfere with post-allo anti-MM effects. Nikolaenko et al (Clin Lymph Myeloma Leuk 2020) reported that aGVHD developed in five (15%) of 34 patients given Dara (mostly in combination) as treatment for post-allo relapse and the median PFS was 4.5 months. METHODS We performed a retrospective study to evaluate the safety and efficacy of Dara post-allo-HSCT). Patients with MM having received at least one Dara infusion at any time after allo-HSCT were included. Key exclusion criteria were plasma cell leukemia and AL amyloidosis. RESULTS A total of 121 patients who received Dara after a first allo-HSCT were identified in the EBMT database. The year of allo-HSCT ranged from 2004 to 2019, median 2014. Allo-HSCT was performed at a median (range) of 34 (6-172) months after the diagnosis of myeloma. The stem cell source was PB in 89%, 37% were matched related donor and 39% matched unrelated donor. Conditioning was reduced intensity in 72% and myeloablative in 28%. Disease status at allo-HSCT was CR in 9%, VGPR in 35 %, PR in 43%, SD/MR in 7% and progression in 6%. The median age (range) at the first Dara infusion was 55 (32-71) yrs with a male to female distribution of 70/51. Dara was administered either alone (n=70) or in combination with other anti-myeloma directed therapy (n=51). The first dose of Dara was given at a median (range) of 30 (1-173) months post-allo-HSCT. Fifteen patients started Dara in the first 6 months after allo-HSCT, 50% of patients in the first 2.5 years, 22% in 2.5 to 5 years, and 28% more than five years after allo-HSCT. Among patients with available data, 45% had at least one serious infection: bacteremia 22% (including 15% ³ grade 3), septic shock 5% (all ³ grade 3), pneumonia 31% (including 21% ³ grade 3), urine infections 7%, CMV reactivation 7% and EBV reactivation 6%. In the first 100 days after starting Dara, aGVHD worsened in 2% (0-4%). The incidence of cGvHD within two years was 5% (1-9%). Dara had been stopped due to adverse events in 10% (95% CI 5-16%) by 24 months. At the same timepoint, 70% (60-79%) of patients had stopped because of progression. The best response to Dara was sCR/CR in 11%, VGPR in 12%, PR in 25%, SD/MR in 20% and progression in 33%. The best response was obtained at a median of 81 days (min-max 7-851 days) after starting Dara. The proportion of at least stable disease was higher when DLI treatment (n=37) was given pre-Dara. The median follow-up from the first dose of Dara was 26.8 months (95% CI 22.3 to 31.1). After starting Dara, the median PFS was 6.5 months, the median TTNT 19.3 months and median OS 21.6 months. Extra-medullary progression post-Dara was observed in 43% of patients for whom there was available data. Bone plasmacytomas were reported in 63%, soft tissues in 33% and both in 4% of cases. In total 13% of patients received a median of two DLI after starting Dara. 47% of patients received other anti-myeloma medications after Dara and 26% received radiotherapy. CONCLUSIONS The use of Dara post-allo-HSCT resulted in stable disease or better in 67% of patients. As reported previously, infections appeared to be common. Compared to the recently published data from Nikolaenko et al, there were fewer cases of aGVHD post-Dara in this retrospective analysis. The PFS were similar in both studies (4.5 vs. 6.5 months) as well as OS (17,4 v 21,6 months). A high proportion of 43% extra-medullary disease progression was observed in the current study which was not reported in the only similar study. Based on these data, Dara treatment for relapsing patients after allo-HCT creates no safety concerns and provides acceptable efficacy Disclosures Vincent: Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Congress support; takeda: Membership on an entity's Board of Directors or advisory committees, Other: Congress support; janssen: Membership on an entity's Board of Directors or advisory committees, Other: Congress support. Minnema:Kite, a Gilead Company: Speakers Bureau; Celgene: Other: travel support, Research Funding; Amgen: Consultancy; Servier: Consultancy. Teipel:janssen: Honoraria. Haenel:Amgen, Novartis, Roche, Celgene, Takeda, Bayer: Honoraria. Forcade:JAZZ: Other: Travel grant for congress; NEOVII: Other: Travel grant for congress; Gilead: Speakers Bureau; Sanofi: Other: Travel grant for congress; Novartis: Other: Travel grant for congress. Schönland:Janssen, Prothena, Takeda: Honoraria, Other: travel support to meetings, Research Funding. Yakoub-Agha:Celgene: Honoraria; Novartis: Honoraria; Gilead/Kite: Honoraria, Other: travel support; Janssen: Honoraria; Jazz Pharmaceuticals: Honoraria. Beksac:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen&janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Deva: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

The European Society for Blood and Marrow Transplantation Chronic Malignancies Working Party held a preceptorship meeting in Turin, Italy on 25-26 September 2014, to discuss the role of stem cell transplantation (SCT) in the treatment of multiple myeloma and other plasma cell disorders. Scientists and clinicians working in the field gathered to discuss a variety of topics including the results of recent clinical trials, basic research, the concept of minimal residual disease, and immune modulation. As individual presentations revealed, important advances have occurred in our understanding of the pathophysiology of myeloma and the role that SCT, along with other forms of immunotherapy, plays in treating it. Each presentation stimulated discussion and exchange of ideas among the attendants. We decided to summarize and, importantly, to update the meeting proceedings in this review to share stimulating discussions and ideas on potentially novel treatment strategies among clinicians.

Background and aims The amount of clinical and biological data stored within clinical trials is growing exponentially. Data warehousing (DW) is useful for systematic global evaluation of information collected in trials: the highly translational FIL(Fondazione Italiana Linfomi)-MCL0208 trial has been used to test DW to improve data quality and to discover putative associations [Zaccaria, ASH 17]. In this study we developed an engineered prognostic model, focusing on easily accessible clinical variables. For this purpose, we exploited hierarchical clustering with the aim of seeking hidden patterns of interest in large datasets. Hence, these tools allowed to develop a novel prognostic model: the engineered MIPI index (e-MIPI). Herein we present the first results, on baseline clinical characteristics:clustering analysis and definition of a signature of predictive variablesconstruction of the e-MIPI to detect patients' risk of relapsecomparison with known prognostic indexes for MCLvalidation of the signature on independent subset of patients. Methods Data were retrieved from electronic case report forms of the phase III, multicenter FIL-MCL0208 trial (NCT02354313) for younger MCL patients [Cortelazzo, EHA 15]. The study enrolled 300 subjects, with median followup of 51 months. In this work we employed baseline clinical data and May '18 as survival outcomes cut-off. For the present analysis, we started from 32 baseline features: 7 were not eligible due to number of missing values (MVs ≥40). Features with Clustering analysis was performed to discriminate different groups of patients. Thus, we applied a recursive feature reduction, according to regression modeling, to extrapolate a restricted signature predictive of both progression free survival (PFS) and overall survival (OS). Survival analyses were done according to e-MIPI classes via both multivariate Cox and Kaplan-Maier modeling. Therefore, the e-MIPI classification was compared to known prognostic models [Hoster, Blood 08]. Finally, the signature was tested on the validation set: if any variable of the e-MIPI was missing (MVs=36, 29 and 15 for albumin - alb, Ki67 and flowcytometric peripheral blood invasion - flowpb) data mining (K-nn) technique was employed for imputation. Clustering and statistical analyses were implemented via MATLAB© and SPSS©. Results Training set: the clustering analysis allowed to define 3 groups of subjects: C1 (n=71), C2 (n=77) and C3 (n=37), showing significantly different PFS and OS. Thus, the e-MIPI index was modeled based on a signature of 9 significant features (fig 1): histologic bone marrow infiltration (bminf), flowpb, Ki67, B symptoms, platelets (plts), ldh, white blood cells (wbc), hemoglobin (hb) and alb levels. The re-clustering of the training set according to the e-MIPI confirmed the original patients clustering with 83% of accuracy. Figure 2A depicts the PFS curves stratified for the e-MIPI: C1, C2 and C3 groups have been renamed as low (L), intermediate (I) and high (H) e-MIPI risk classes, respectively. Each comparison reached the statistical significancy: I vs L, p=0.010; H vs I, p=0.023, outperforming in our series both the MIPI-St (H vs I risk, p=0.801) and MIPI-Bio (I vs L risk, p=0.665, fig. 2B) classifications. Validation set: the e-MIPI allowed to discriminate 3 groups of subjects C1 (n=32), C2 (n=59) and C3 (n=24). Actually, the e-MIPI on the validation set (fig. 2C) confirmed the results of the training set, overall improving the MIPI-St stratification (H vs I, p=0.059 ⇒ p=0.049), even if without reaching the statistical significancy on the I vs L comparison (p=0.24 ⇒ p=0.15), due to the limited number of events in this series. Discussion e-Mipi is a new first prognostic index derived from hierarchical clustering. Our results indicate that this approach might allow to model engineered prognostic indexes based on comprehensive analysis of large datasets. Even if promising, it needs validation through its application to independent series of MCL patients. Additional efforts aiming at integrating biological variables in the model are ongoing. Disclosures Gaidano: Amgen: Consultancy, Honoraria; Morphosys: Honoraria; Janssen: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Roche: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria. Ladetto:Celgene: Honoraria; Sandoz: Honoraria; Jannsen: Honoraria; Roche: Honoraria; Abbvie: Honoraria; Acerta: Honoraria.

The immunoglobulin heavy-chain variable region (IGHV) mutational status is a strong determinant of remission duration in chronic lymphocytic leukemia (CLL). The aim of this work was to compare the multidrug resistance (MDR) signature of IGHV mutated and unmutated CLL cells, identifying biochemical and molecular targets potentially amenable to therapeutic intervention. We found that the mevalonate pathway-dependent Ras/ERK1–2 and RhoA/RhoA kinase signaling cascades, and the downstream HIF-1α/P-glycoprotein axis were more active in IGHV unmutated than in mutated cells, leading to a constitutive protection from doxorubicin-induced cytotoxicity. The constitutive MDR phenotype of IGHV unmutated cells was partially dependent on B cell receptor signaling, as shown by the inhibitory effect exerted by ibrutinib. Stromal cells further protected IGHV unmutated cells from doxorubicin by upregulating Ras/ERK1–2, RhoA/RhoA kinase, Akt, HIF-1α and P-glycoprotein activities. Mevalonate pathway inhibition with simvastatin abrogated these signaling pathways and reversed the resistance of IGHV unmutated cells to doxorubicin, also counteracting the protective effect exerted by stromal cells. Similar results were obtained via the targeted inhibition of the downstream molecules ERK1–2, RhoA kinase and HIF-1α. Therefore, targeting the mevalonate pathway and its downstream signaling cascades is a promising strategy to circumvent the MDR signature of IGHV unmutated CLL cells.

In this past decade, new therapeutic approaches based on the use of rituximab, high-dose cytosine-arabinoside, and autologous stem cell transplantation (ASCT) have changed the paradigm of mantle cell lymphoma (MCL) treatment, significantly improving the quality and duration of response and

Background Tumor regression after antiviral therapy (AT) is in favor of an etiological role of hepatitis C virus (HCV) in non-Hodgkin's B-cell lymphomas (NHL). Patients and methods We carried out a cohort study of 704 consecutive HIV-negative, HCV-positive patients with indolent NHL diagnosed and treated from 1993 to 2009 in 39 centers of the Fondazione Italiana Linfomi; 134 patients were managed with AT for lymphoma control. Results For entire cohort, 5-year overall survival (OS) was 78% [95% confidence interval (CI): 74%–82%] and 5-year progression-free survival (PFS) was 48% (95% CI: 44%–53%). In multivariate analysis, the use of AT during the patients’ life had positive impact on OS. Forty-four of the 100 patients treated with first-line AT achieved a complete remission (CR) and 33 a partial response (PR). HCV-RNA clearance was achieved in 80 patients and was related to lymphoma response. At a median follow-up of 3.6 years, 5-year PFS was 63% (95% CI: 50%–73%). CR + PR rate was 85% with AT as second-line treatment. Conclusion AT produces HCV-RNA clearance and consequent tumor regression in most patients with HCV-related indolent NHL. AT used at any time is associated with improved OS. Consequently, AT can be considered an option for patients with indolent lymphomas who do not need immediate cytoreductive treatment.

Background: Mantle cell lymphoma (MCL) is a distinct subtype of lymphoma with a wide variation of clinical course. Based on randomized trials of our network, current standard of care is a cytarabine-containing immunochemotherapy induction (Hermine, Lancet 2016) followed by autologous stem cell transplantation (SCT; Zöllner, ICML 2019) and rituximab maintenance for 3 years (Le Gouill, NEJM 2018). In relapsed MCL the BTK inhibitor ibrutinib achieves high response rates and ongoing remissions (Wang, NEJM 2013; Dreyling, Lancet 2016). This approach achieved especially longer remission durations in earlier treatment lines (Rule, Hamatologica 2019). We aim to clarify whether ibrutinib added to induction and as maintenance with or without autologous stem cell transplantation might improve outcome. Study design and methods: In this international, randomized three-arm phase III trial (EudraCT-no. 2014-001363-12) young, fit patients ( up to 65 years) with histologically confirmed, untreated mantle cell lymphoma advanced stage II-IV qualify for 1:1:1 randomization after written informed consent according to ICH/EU GCP. In the control arm A, patients receive an alternating R-CHOP/R-DHAP induction followed by myeloablative consolidation (either BEAM or THAM: TBI, high dose Ara-C and melphalan). In arm A+I Ibrutinib is added to the R-CHOP cycles (560 mg day 1-19) and applied as maintenance (continuous dosing) for 2 years. In arm I the same induction and maintenance is applied but high dose consolidation and autologous SCT is skipped. A rituximab maintenance (single doses every 2 months up to 3 years) may be added in all study arms according to national clinical routine. The primary study aim is to show superiority of one of three study arms as future standard of care based on the comparison of the investigator-assessed failure-free survival (FFS), i.e. to investigate if the addition of ibrutinib improves the efficacy of standard 1st line treatment, and can even challenge the use of high-dose chemotherapy with autologous SCT. Secondary study aims include the efficacy of the three treatment arms and the safety and tolerability of ibrutinib during induction immuno-chemotherapy and maintenance. Accordingly, overall and complete response rates, progression-free and overall survival will be determined as well as adverse events during induction immuno-chemotherapy and follow-up including the cumulative incidence rates of SPMs. In addition, minimal residual disease is regularly determined based on patient-specific PCR assay according to the standardized Biomed-2 procedure. Results: As of July 30th, 511 of up to 870 patients have been randomized from 12 different European countries. In a meanwhile completed safety run-in of the initial 50 patients, feasibility of the two experimental arms was confirmed with no major differences in hematological and other toxicities and no major delays during induction. Disclosures Dreyling: Acerta: Other: Scientific advisory board; Novartis: Other: Scientific advisory board; Mundipharma: Other: Scientific advisory board, Research Funding; Janssen: Other: Scientific advisory board, Research Funding, Speakers Bureau; Gilead: Other: Scientific advisory board, Speakers Bureau; Celgene: Other: Scientific advisory board, Research Funding, Speakers Bureau; Bayer: Other: Scientific advisory board, Speakers Bureau; Sandoz: Other: Scientific advisory board; Roche: Other: Scientific advisory board, Research Funding, Speakers Bureau. Ladetto:Roche: Honoraria; AbbVie: Honoraria; J&J: Honoraria; Celgene: Honoraria; Pfizer: Honoraria, Speakers Bureau; Acerta: Honoraria, Speakers Bureau; ADC Therapeutics: Honoraria. Doorduijn:Roche: Honoraria, Research Funding. Gine:Janssen: Other: Travel expenses, Research Funding; Gilead: Other: Travel expenses, Research Funding; Roche: Other: Travel expenses, Research Funding. Jerkeman:Janssen: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; Acerta: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Roche: Honoraria, Research Funding. Mey:Janssen-Cilag: Consultancy; Roche: Consultancy, Research Funding. Hutchings:Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Celgene: Research Funding; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Research Funding. Kolstad:Merck: Research Funding; Nordic Nanovector: Membership on an entity's Board of Directors or advisory committees, Research Funding. Trneny:Roche: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Gilead sciences: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria. Gomes da Silva:AbbVie: Consultancy, Other: Travel support; Roche: Consultancy, Other: Travel support; Janssen-Cilag: Consultancy, Other: Travel support; Celgene: Consultancy; Gilead Siences: Other: Travel support, Research Funding. Klapper:Roche, Takeda, Amgen, Regeneron: Honoraria, Research Funding. Unterhalt:F. Hoffmann-La Roche: Research Funding. Hoster:Janssen: Research Funding; Roche Pharma AG: Other: Travel Support.

Introduction: Most patients with newly diagnosed FL treated with rituximab (R) alone or R + chemotherapy will experience prolonged progression-free survival and overall survival (OS), but it remains unclear what factors have the greatest influence on FL-associated and other causes of death in this patient population. We utilized individual patient data from 13 first-line randomized clinical trials from the FLASH database to perform a comprehensive multistate survival analysis to examine and quantify the relationships between clinical characteristics, treatment response, and early, intermediate, and late FL outcomes. Methods: The multistate survival analysis model defined states for "Alive after beginning Induction Treatment (TX)", "Alive after beginning Maintenance TX", "Death due to FL", and "Death from Other Causes" (Figure 1). We used the Aalen-Johansen estimator, a generalization of the Kaplan-Meier estimator, to calculate the likelihood of being in each model state and estimate the course of FL over time. Making no assumptions on the probability distributions and capable of coping with censored observations, the Aalen-Johansen estimator is a convenient and reliable nonparametric estimator for clinical data. Results: Among 7,465 FL patients with median age 56 (range 18-90) years, 49.2% were female; 28.7% Stage I-III, 71.3% Stage IV, and FLIPI was 0-1 (20.0%), 2 (36.8%), ≥ 3 (43.2%). Following initiation of induction treatment, 2-, 5- and 10-year death rates were 1.7%, 3.8%, and 5.8% due to FL, and 0.7%, 2.1%, and 4.8% from other causes (Figure 2). Death rates at 2, 5, and 10 years due to FL and other causes for subgroups based on clinical characteristics and treatment response are shown in Table 1. Notably, patients > 70 years and patients with FLIPI ≥ 3 had worse outcomes and patients achieving CR at 18, 24, and 30 months experienced improved outcomes. Conclusion: This is the largest study using data from randomized trials to quantify the impact of clinical factors on early, intermediate and late mortality by cause of death. We demonstrated that age > 70 years and FLIPI ≥ 3 were linked to increased FL-associated death and response to TX distinguished patients with favorable and poor outcomes. Future analyses should quantify the impact of predictors on the rate/time of FL outcomes in multivariable models. Disclosures Salles: Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Amgen: Honoraria, Other: Educational events; BMS: Honoraria; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis, Servier, AbbVie, Karyopharm, Kite, MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Epizyme: Consultancy, Honoraria; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events. Hoster:Janssen: Research Funding; Roche Pharma AG: Other: Travel Support. Hiddemann:Bayer: Research Funding; Gilead: Consultancy, Honoraria; Vector Therapeutics: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria. Herold:Roche: Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Gilead: Honoraria; Celgene: Honoraria. Morschhauser:Servier: Consultancy; Gilead: Consultancy; Janssen: Honoraria; Roche/Genentech: Consultancy; BMS: Honoraria; Celgene: Honoraria. Rummel:Roche Pharma AG: Honoraria, Research Funding; Celgene: Honoraria; Janssen: Honoraria; Sandoz: Honoraria. Kimby:AbbVie,: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Jansen: Membership on an entity's Board of Directors or advisory committees; Gilead: Other: educational lectures. Vitolo:Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche: Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Gyan:Pfizer: Honoraria. Ladetto:Celgene: Honoraria; Roche: Honoraria; Janssen: Honoraria; Abbvie: Honoraria; Acerta: Honoraria; Sandoz: Honoraria. Nielsen:F. Hoffmann-La Roche Ltd: Employment, Equity Ownership. Flowers:AstraZeneca: Consultancy; BeiGene: Consultancy, Research Funding; Eastern Cooperative Oncology Group: Research Funding; Burroughs Wellcome Fund: Research Funding; AbbVie: Consultancy, Research Funding; Optimum Rx: Consultancy; V Foundation: Research Funding; Pharmacyclics/Janssen: Consultancy, Research Funding; Bayer: Consultancy; Gilead: Consultancy, Research Funding; TG Therapeutics: Research Funding; Denovo Biopharma: Consultancy; Acerta: Research Funding; National Cancer Institute: Research Funding; Millenium/Takeda: Research Funding; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Spectrum: Consultancy

Introduction: Management of elderly patients with Diffuse Large B-Cell Lymphoma (DLBCL) is challenging. A simplified Comprehensive Geriatric Assessment (sCGA) based on ADL (Activity of Daily Living), IADL (Instrumental ADL) and CIRS-G (Comorbidity Index Rating Scale for Geriatrics) scales has demonstrated to be better than clinical judgement to stratify patients' outcome but has never been included in initial assessment. To further assess the impact of sCGA on patients' outcome, we conducted a prospective observational study on a large series of elderly patients with DLBCL. Methods: Patients were enrolled if 65 year old or older, with an untreated de novo DLBCL. sCGA was available at a web based platform that classified patients as FIT, UNFIT, and FRAIL, as shown in Table 1. Treatment choice was left at physician discretion. According to anthracycline dose, therapy was classified as curative (≥70% of full anthracycline dose), intermediate ( Results: From December 2013 to December 2017, 1353 patients have been registered by 37 centres and 1207 were eligible. Median age was 76 years (65-94), 68% had stage III-IV, and 55% had an International Prognostic Index(IPI) ≥3; 500 (42%), 304 (25%), and 403 (33%) were classified as FIT, UNFIT and FRAIL, respectively. Data on treatment were available in 1164 patients: rituximab was used in 96% of patients; treatment was curative in 89%, 53%, and 36% of FIT, UNFIT, and FRAIL patients, respectively; intermediate in 10%, 39%, and 31%, palliative in 0%, 8%, and 33% of patients. The OS was available in 1158 out 1164 cases. With a median follow up of 30 months (1-59) 3y-OS was 64% (95% CI 61% to 67%). According to sCGA the OS was significantly different among the 3 geriatric groups. Correlation with OS was improved when sCGA was integrated with age < or ≥ 80 years to define 3 groups of patients (Table 2): FIT and UNFIT younger than 80 years (sCGA Group 1; 55%, 3 yr OS 75%), UNFIT ≥ 80 years and FRAIL younger than 80 years (sCGA Group 2: 28%, 3yr OS 58%), FRAIL ≥ 80 years (sCGA Group 3: 17%; 3yr OS 43%). Univariable and multivariable analysis for OS was conducted using the 3 sCGA groups and other clinical and laboratory features. The 3 sCGA groups were shown as independent prognostic factors with IPI and with anemia (Hb < 12 g/dl). We used results of multivariable analysis to build a categorical prognostic index assigning different weights to prognostic features based on their Hazard Ratio (HR) (Table 3). The Elderly Prognostic Index (EPI) was defined as the score obtained from the sum of the weights and allowed to define 3 risk groups: Low Risk (LR: score 0-1; 23% of patients); Intermediate Risk (IR; score 2-4; 48%); High Risk (HiR; score 5-7; 29%). The 3 EPI risk groups had a different 3 year OS of 87%(95%CI 81-91), 69%(95%CI 63-73), and 42% (95%CI 36-49); HR for IR vs LR 2.57 (1.72, 3.84); HiR vs LR 6.21(4.17 -9.25), HiR vs IR 2.42 (1.91-3.05) (Figure1). Regarding treatment modality, curative, intermediate and palliative therapies were adopted in 89%, 10%, and 1% of the LR group; 70%, 24%, 7% of the IR group, and 37%, 35%, 28% of the HiR group. The model was internally validated by means of 1000 procedures confirming good performance (slope shrinkage 0.935 and c-Harrell 0.675 in validation sample compared with 0.682 in training sample). The EPI was also tested in an external validation data set that was identified from the pivotal study of sCGA in DLBCL (N=172 patients, Tucci A. et al, Leuk Lymph, 2015) (Figure 1). Conclusion: Using data from this large prospective observational study on elderly DLBCL patients we were able to build a new prognostic index that allows to identify 3 risk groups with significant differences in terms of 3 years OS. The EPI is the first index that integrates geriatric assessment with clinical features and contributes to improving management and clinical research in elderly patients with DLBCL. Disclosures Spina: Servier: Membership on an entity's Board of Directors or advisory committees, Other: lecture fee; Sandoz: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Membership on an entity's Board of Directors or advisory committees, Other; Roche: Other: lecture fee; Teva: Membership on an entity's Board of Directors or advisory committees, Other: lecture fee; GILEAD: Membership on an entity's Board of Directors or advisory committees, Other: lecture fee; Celgene: Other: lecture fee; BMS: Other: lecture fee; Sanofi Genzyme: Other: lecture fee; CTI: Membership on an entity's Board of Directors or advisory committees, Other: lecture fee; Menarini: Membership on an entity's Board of Directors or advisory committees, Other: lecture fee, Research Funding; Takeda: Other: lecture fee; Janssen-Cilag: Membership on an entity's Board of Directors or advisory committees, Other: lecture fee; Pfizer: Membership on an entity's Board of Directors or advisory committees. Merli:Janssen: Honoraria; Takeda: Honoraria, Other: Travel Expenses; Gilead: Honoraria; Mundipharma: Honoraria; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Research Funding; Sandoz: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses. Cavallo:Takeda: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Ladetto:Roche: Honoraria; AbbVie: Honoraria; J&J: Honoraria; Celgene: Honoraria; ADC Therapeutics: Honoraria; Acerta: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau. Chiappella:Celgene: Other: advisory board, Speakers Bureau; Janssen: Other: advisory board, Speakers Bureau; Servier: Other: advisory board, Speakers Bureau; Roche: Speakers Bureau; Teva: Speakers Bureau. Nassi:Takeda: Consultancy; Janssen: Consultancy; Merck: Consultancy. Ferrero:Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Speakers Bureau; Servier: Speakers Bureau; EUSA Pharma: Membership on an entity's Board of Directors or advisory committees. Luminari:ROCHE: Membership on an entity's Board of Directors or advisory committees; CELGENE: Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; GILEAD: Other: Lecturer; TAKEDA: Other: Travel Grant.

Introduction Limited stage follicular lymphoma (FL) is usually managed with involved field radiotherapy (IFRT), although different approaches are currently carried out, ranging from watch and wait to combined treatment. RT on involved lymph nodes allows eradication of the disease only in 40-50% of patients. Anti-CD20 monoclonal antibodies (MoAb), widely used in advanced stage FL, are likely to be effective in reducing the relapse risk, although no scientific evidence of their role has been provided. The aim of this multicenter phase II prospective study was to evaluate the role of MRD in identifying patients unlikely to be cured by RT, for whom an immunotherapy-based consolidation could improve outcome. Methods 110 patients with stage I/II FL were enrolled. IFRT was administered to all patients at a dose of 24 Gy. Peripheral blood (PB) and bone marrow (BM) samples were centralized to the Italian FIL (Federazione Italiani Linfomi) MRD Network of EuroMRD-certified laboratories: the presence of a BCL2/IGH rearrangement was investigated at baseline in all patients by nested PCR (NEST) and RQ-PCR (RQ), the latter according to the EuroMRD guidelines. In patients BCL2/IGH+ at baseline by both NEST and RQ in BM and/or PB, MRD was analyzed in both tissues after IFRT and every 6 months over a three-year follow-up period. Patients with positive MRD by both NEST and RQ in BM and/or PB after IFRT or who became positive during the follow-up were treated with 8 weekly doses of the anti-CD20 MoAb ofatumumab. The primary objective of the study was to define the efficacy of immunotherapy in obtaining the disappearance of BCL2/IGH rearranged cells. Results Preliminary data are available for 107 patients, 57 males, 50 females. Median age was 55 years (29-83). 17% had G1 FL, 32% G2, 40% G3A, 11% NOS. The FLIPI score was 0 in 59% of patients, 1 in 35%, 2 in 6%. 69% of patients had inguinal site involvement. Despite a negative BM biopsy, at baseline 30% of patients (n=32) had a BCL2/IGH rearrangement (30 MBR, 1 MBR and mcr, 1 mcr) in the BM and/or PB; the concordance between compartments was 90%, with 10% of negative PB showing a positive BM. No significant differences were observed in relapse probability between patients with or without a molecular marker. All patients were submitted to IFRT and all obtained a clinical response, which was complete in 79 of the 101 evaluated patients (78%) and partial in 22 (22%). MRD evaluation after treatment revealed the persistence of BCL2/IGH rearranged cells in the PB and/or BM in 60% of patients. According to the design of the protocol, MRD-positive patients, either after IFRT (n=18) or in case of conversion to a positive signal during the follow-up (n=7), received 8 weekly administration of ofatumumab. A conversion to MRD negativity, evaluated in 23 treated patients, was obtained in 20 (87% - CI 65.1-97.1). This result was significantly superior to the expected 50%. One death occurred after IFRT, due to ischemic stroke. Adverse events likely correlated to ofatumumab occurred in 7/25 treated patients, consisting of infusion reactions in 5, leading to a permanent interruption of immunotherapy in 3. After a median follow-up of 18 months, all patients who achieved a MRD negativity with ofatumumab underwent a regular molecular follow-up and are still MRD-negative. Overall, clinical relapse or progression were observed in 17 patients: 13 (18%) among the 73 "no marker" patients; 2 relapses (16%) were observed among the 12 MRD-negative patients after IFRT and 2 relapses were observed among the 23 patients treated with the anti-CD20 MoAb (8.7%), 1 having achieved a MRD negativity and 1 not. No significant differences in event-free survival have so far been observed between the three groups. Conclusions The MRD data of this phase II trial for early stage FL indicate that RT alone is often insufficient to eradicate the disease, being capable of inducing a negative MRD only in 40% of evaluable cases, with a long-lasting effect only in half of them. The primary objective of this study - MRD negativity after immunotherapy - was achieved, obtaining the disappearance of BCL2/IGH rearranged cells in the majority of patients treated with ofatumumab. The strategy of an immunotherapy consolidation after IFRT in MRD-positive patients allowed to increase molecular responses. A longer follow-up and further studies on larger patient populations will allow to conclusively define the impact of this MRD-driven strategy also on clinical outcome. Disclosures Pulsoni: Roche: Consultancy, Speakers Bureau; Takeda: Consultancy; Pfizer: Consultancy; Sandoz: Consultancy; Gilead: Speakers Bureau; Merk: Consultancy; Bristol Meyer Squibb: Speakers Bureau. Ferrero:Servier: Speakers Bureau; EUSA Pharma: Membership on an entity's Board of Directors or advisory committees; Gilead: Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Luminari:ROCHE: Other: Role as Advisor ; CELGENE: Other: Role as Advisor & Travel Grant; TAKEDA: Other: Travel Grant; GILEAD: Other: Lecturer . Liberati:Amgen: Membership on an entity's Board of Directors or advisory committees, Other: Clinical trial support; Celgene: Honoraria, Other: Clinical trial support; Bristol-Myers Squibb: Honoraria; Takeda: Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy; Janssen: Honoraria; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Clinical trial support; Roche: Other: Clinical trial support; Novartis: Other: Clinical trial support. Ferreri:Roche: Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Kite: Consultancy. Nassi:Takeda: Consultancy; Janssen: Consultancy; Merck: Consultancy. Corradini:Roche: Honoraria; Novartis: Honoraria; kite: Honoraria; KiowaKirin: Honoraria; Janssen: Honoraria; Gilead: Honoraria; Daiichi Sankyo: Honoraria; Celgene: Honoraria; Amgen: Honoraria; Abbvie: Honoraria; Servier: Honoraria; Sanofi: Honoraria; Takeda: Honoraria. Mannina:Janssen: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees. Arcaini:Celgene: Speakers Bureau; Gilead Sciences: Research Funding; Bayer, Celgene, Gilead Sciences, Roche, Sandoz, Janssen-Cilag, VERASTEM: Consultancy; Celgene, Roche, Janssen-Cilag, Gilead: Other: Travel expenses. Galimberti:Roche: Speakers Bureau; Celgene: Speakers Bureau; Novartis: Speakers Bureau. Ladetto:AbbVie: Honoraria; Roche: Honoraria; ADC Therapeutics: Honoraria; Acerta: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau; J&J: Honoraria; Celgene: Honoraria. Foà:Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Shire: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; Celltrion: Membership on an entity's Board of Directors or advisory committees; Amgen Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Shire: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. OffLabel Disclosure: The anti-CD20 MoAb Ofatumomab is employed to eradicate Minimal Residual Disease in early stage Follicular Lymphoma(FL). The drug is registered for Chronic Lymphocytic Leukemia, not for FL.

Introduction: The only curative treatment for myelofibrosis (MF) remains allogenic haematopoietic cell transplantation (allo-HCT) although the risks of non-relapse mortality (NRM), relapse and graft rejection need to be taken into consideration. Therapeutic approaches following relapse after allo-HCT include symptom-directed management, chemotherapy, JAK2 inhibitors, adoptive immunotherapeutic approaches with donor lymphocyte infusion (DLI) and, in a minority, a second allo-HCT. Frequently, due to the advanced age of the recipient, early relapses, and numerous complications, 2nd allo-HCT can only be considered in a limited number of patients. Few studies evaluating the role of 2nd allo-HCT in MF following 1st relapse or primary/secondary graft rejection have been published to date. Methods and results: Patient selection was performed by identifying adult patients who underwent 2nd allo-HCT for MF between 2010-2017: 216 patients were analyzed; 64% were male, 78% had primary MF (PMF) and 22% secondary MF (sMF). Median age at the time of 2nd allo-HCT was 57 years, and median time from 1st allo-HCT was 8 months. Of this cohort, 56% of patients received a 2nd allo-HCT for relapse, 31% for graft failure and the reason was missing in 13%. A greater proportion was transplanted within 1 year from 1st allo-HCT (61 %) whilst 39% had 2nd allo-HCT > 1 year. A reduced Karnofsky performance status (KPS12 months, p=0.02). The 2-year relapse-free-survival (RFS) for the entire cohort was 44%. Only time elapsed from the 1st allo-HCT to 2nd was significantly associated with 2-year RFS (41% for ≤12 months, 49% for >12 months, p=0.05). Of note, the 2-year OS and RFS were comparable following use of the same or a different donor. The 2-year cumulative incidence of relapse and NRM were 22 and 34%, respectively. The time interval from 1st to 2nd allo-HCT appeared to be highly significant for NRM with patients transplanted ≤12 months having a higher 2-year NRM compared to those transplanted >12 months (40 vs 24%, respectively, p=0.008). A trend for higher NRM was the reason for 2nd allo-HCT: patients transplanted for graft rejection had a 2-year NRM of 45% compared to 31% for those with relapse (p=0.06). Conclusions: This analysis supports the utilization of a 2nd allo-HCT for patients with MF who have presented with graft failure or relapse following a 1st allo-HCT. In univariate analysis, overall outcome appears worse in patients being transplanted after graft failure as well as for those transplanted within 1 year after 1st allo-HCT, due to increased NRM. Of note, the use of either the original or a different donor are associated with similar outcomes. Further work is required to elucidate other risk factors, GVHD rates and to define the optimal conditioning regimen in this setting. Table. Disclosures Robin: Novartis Neovii: Research Funding. Kröger:Sanofi-Aventis: Honoraria; Riemser: Research Funding; Novartis: Honoraria, Research Funding; Neovii: Honoraria, Research Funding; Medac: Honoraria; JAZZ: Honoraria; DKMS: Research Funding; Celgene: Honoraria, Research Funding. Angelucci:Celgene: Honoraria, Other: Participation in DMC; BlueBirdBio: Other: Local advisory board; Jazz Pharmaceuticals: Other: Local advisory board; Roche: Other: Local advisory board; Vertex Pharmaceuticals Incorp., and CRISPR Therapeutics: Other: Participation in DMC; Novatis: Honoraria, Other: Chair Steering Committee TELESTO protocol. Dreger:AbbVie, AstraZeneca, Gilead, Janssen, Novartis, Riemser, Roche: Consultancy; AbbVie, Gilead, Novartis, Riemser, Roche: Speakers Bureau; MSD: Membership on an entity's Board of Directors or advisory committees, Other: Sponsoring of Symposia; Neovii, Riemser: Research Funding. Platzbecker:Celgene: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria. Rambaldi:Novartis: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau; Italfarmaco: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Omeros: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Mayer:AOP Orphan Pharmaceuticals AG: Research Funding. Ladetto:ADC Therapeutics: Honoraria; Pfizer: Honoraria, Speakers Bureau; Celgene: Honoraria; J&J: Honoraria; Roche: Honoraria; AbbVie: Honoraria; Acerta: Honoraria, Speakers Bureau. Hernandez Boluda:Incyte: Other: Travel expenses paid. McLornan:Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Novartis: Honoraria. Chalandon:Incyte Biosciences: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria.

Aggressive double- and triple-hit (DH/TH) diffuse large B-cell lymphomas (DLBCLs) feature activation of Hsp90 stress pathways. Herein, we show that Hsp90 controls posttranscriptional dynamics of key messenger RNA (mRNA) species including those encoding BCL6, MYC, and BCL2. Using a proteomics approach, we found that Hsp90 binds to and maintains activity of eIF4E. eIF4E drives nuclear export and translation of BCL6, MYC, and BCL2 mRNA. eIF4E RNA-immunoprecipitation sequencing in DLBCL suggests that nuclear eIF4E controls an extended program that includes B-cell receptor signaling, cellular metabolism, and epigenetic regulation. Accordingly, eIF4E was required for survival of DLBCL including the most aggressive subtypes, DH/TH lymphomas. Indeed, eIF4E inhibition induces tumor regression in cell line and patient-derived tumorgrafts of TH-DLBCL, even in the presence of elevated Hsp90 activity. Targeting Hsp90 is typically limited by counterregulatory elevation of Hsp70B, which induces resistance to Hsp90 inhibitors. Surprisingly, we identify Hsp70 mRNA as an eIF4E target. In this way, eIF4E inhibition can overcome drug resistance to Hsp90 inhibitors. Accordingly, rational combinatorial inhibition of eIF4E and Hsp90 inhibitors resulted in cooperative antilymphoma activity in DH/TH DLBCL in vitro and in vivo.

Early identification of patients at high risk of relapse is a major goal of current translational research in oncohematology. Minimal residual disease (MRD) detection by polymerase chain reaction-based methods is currently part of the routine clinical management of patients with acute lymphoblastic leukemia. However, the current knowledge indicates that it is also a useful prognostic tool in several mature lymphoproliferative disorders. Its utility is currently well established in follicular lymphoma, mantle cell lymphoma, and multiple myeloma. In some of these entities, clinical trials employing MRD as a decision-making tool are currently ongoing. In the present review, we will discuss the 'state of the art' of MRD evaluation in these three neoplasms with the ultimate aim of providing critical take-home messages for clinicians working in the field. Moreover, we will outline the role of MRD detection in the design of future clinical trials.

Tumor cells in chronic lymphocytic leukemia (CLL) are more prone to apoptosis when cultured ex vivo, because they lack prosurvival signals furnished in vivo via B-cell receptor (BCR)-dependent and -independent pathways. This study compared the susceptibility of unmutated (UM) and mutated (M) CLL B cells to spontaneous apoptosis and prosurvival signals. UM CLL B cells showed a significantly higher rate of spontaneous apoptosis than M CLL B cells. Nuclear factor-kB (NF-kB) was rapidly inactivated, and B-cell leukemia/lymphoma 2 (Bcl-2) expression progressively down-regulated in the UM CLL B cells. CD40-Ligand, interleukin-4 and stromal cells significantly improved their viability and partially recovered Bcl-2, but not NF-kB expression. Peripheral blood mononuclear cells also offered protection of UM CLL B cells, and recovered both NF-kB and Bcl-2 expression. T cells, rather than nurse-like cells, were responsible for protecting UM CLL B cells by means of cell-to-cell contact and soluble factors. Despite their more aggressive features, UM CLL B cells are more susceptible to spontaneous apoptosis and depend from environmental prosurvival signals. This vulnerability of UM CLL B cells can be exploited as a selective target of therapeutic interventions.

Background and Aims. Minimal residual disease (MRD) detection by PCR-based methods is a relevant outcome predictor in MCL, however it is not clear which might represent the most effective methodology (nested vs real-time quantitative PCR, RQ-PCR), the most informative tissue source (bone marrow, BM, vs peripheral blood, PB), the best timing of analysis (midterm vs post-therapy) and the added value of performing multiple MRD determinations. To address these issues a systematic MRD detection program was performed in the Fondazione Italiana Linfomi (FIL) MCL0208 trial (NCT02354313), a prospective, randomized phase III trial comparing lenalidomide maintenance vs observation after an intensive citarabine containing chemo-immunotherapy (R-HDS) program followed by ASCT in 300 frontline MCL patients Disclosures Vitolo: Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sandoz: Speakers Bureau; Gilead: Speakers Bureau; Takeda: Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Background. Ara-c based chemo-immunotherapy followed by autologous stem cell transplantation (ASCT) is the most effective approach in young mantle cell lymphoma (MCL) patients, though few if any patients are cured. Recent data indicate that subsequent Rituximab maintenance (RM) prolongs PFS and OS (Le Gouill NEJM 2017). Lenalidomide is an oral agent effective in MCL, considered suitable for prolonged maintenance programs, but has never been tested in this setting. The FIL MCL0208 trial (NCT02354313) is a prospective, international randomized, phase III trial, comparing Lenalidomide maintenance (LM) vs observation (OBS) after an intensive Ara-c containing chemo-immunotherapy (R-HDS) program, followed by ASCT in previously untreated MCL patients. Patients and Methods. Adult patients aged 18-65 years, with advanced stage MCL without clinically significant comorbidities were enrolled. Patients received 3 R-CHOP-21, followed by R-HDS i.e. R-high-dose Cyclophosphamide (R-HD-CTX) (4g/m2), 2 cycles of R-high-dose Ara-C (R-HDAC) (2g/m2 q12x3 d). CD34+ cells were collected after the first course of R-HDAC. The conditioning regimen for ASCT was BEAM. After ASCT, responding patients were randomized between LM (15 mg days 1-21 every 28 days) for 24 months or observation. Primary endpoint analysis was scheduled at the occurrence of the 60th PFS event in the randomized population, which occurred on June 20th, 2017 and data were analyzed for the present abstract on March 3rd 2018. Results. Three-hundred three patients were enrolled from May 2008 to August 2015 by 48 Italian and 1 Portuguese Center. Three patients were excluded after central histological review. Median age was 57 years (IQR 51-62), M/F ratio 3.6/1. Ninety-two percent of patients had stage IV, 33% bulky disease (>5 cm), 33% elevated LDH, and 75% BM infiltration. Ki67 ≥30% was observed in 32%, MIPI was low (L) in 54%, intermediate in 31% and high (H) in 15% of patients. MIPI-c was L in 49%, low-intermediate (LI) in 29%, high-intermediate (HI) in 14%, H in 9%. Nine percent had blastoid variant. Fifty-two (17%) patients interrupted treatment before randomization (8 toxic deaths, 1 death for car accident, 24 progressions and 19 toxicity/refusals). On an ITT basis, the R-HDS + ASCT program induced 78% of CR, 7% of PRs, 10% of PD, 3% of toxic deaths (TRM) and 2% NA. Median follow-up (mFU) from inclusion was 51 months. Three years PFS and OS for the enrolled population were 67% and 84%, respectively. Of 248 patients who received ASCT, 205 were randomized either to LM (n=104) or OBS (n=101) and 43 (17%) were not because of: lack of response (8), refusal/PI decision/delay (8), unresolved infections (3) and inadequate hematopoietic recovery (24). Feasibility and efficacy were assessed on an ITT basis while toxicity was analyzed on subjects receiving at least one Lenalidomide dose. In the LM arm, 53 out of 104 patients did not start or complete the planned maintenance because of death (2), AE (26), PD (7), still ongoing (2), other causes (16). In the OBS arm 32 patients did not complete the observation phase because of death (1), AE (1), PD (20), still ongoing (10), other causes (1). Overall 28% of patients received less than 25% of the planned Lenalidomide dose. Despite suboptimal exposure to study drug, with a mFU from randomization of 35 months, 22 PFS events were recorded in the LM cohort vs 38 in the OBS arm, resulting in a 3y-PFS of 80% (95% CI; 70%-87%) in the LM arm vs. 64% in the OBS arm (95% CI; 53%-73%), stratified HR 0.51; 95% CI 0.30-0.87; p=0.013 (Fig 1A). OS was superimposable in the two arms: 93% vs 86%, stratified HR 0.96, 95% CI 0.44-2.11, p= 0.91 (Fig1B). Two deaths were observed in the LM arm due to pneumonia and thrombotic thrombocytopenic purpura and one in the OBS arm due to pneumonia. Grade 3-4 hematological toxicity was seen in 63% of patients in LM vs 11% in the OBS arm with 59% vs 10% of patients experiencing granulocytopenia. Non-hematological grade 3 toxicity was comparable in the two arms except grade 3-4 infections (11% vs. 4%; Fisher's p=0.10). Second cancers occurred in 7 patients in the LM and 3 in the OBS arm (Fisher's p=0.20). Conclusions. Results from the MCL0208 trial indicate that LM has a clinically meaningful anti-lymphoma activity in MCL. However, the applicability of LM has some limitations in the context of patients undergoing intensified chemoimmunotherapy. Overall these data support the use of a maintenance regimen after ASCT in young MCL patients. Disclosures Ladetto: Roche: Honoraria; Celgene: Honoraria; Acerta: Honoraria; Jannsen: Honoraria; Abbvie: Honoraria; Sandoz: Honoraria. Di Rocco:Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Rossi:Novartis: Honoraria; Jazz: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Amgen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Janssen: Membership on an entity's Board of Directors or advisory committees, Travel expenses; Roche: Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria; Mundipharma: Honoraria; Sandoz: Honoraria; Seattle Genetics: Research Funding; Alexion: Other: Travel expenses. Chiappella:Janssen: Membership on an entity's Board of Directors or advisory committees, Other: lecture fees; Roche: Other: lecture fees; Teva: Other: lecture fees; Nanostring: Other: lecture fees; Amgen: Other: lecture fees; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: lecture fees. Rusconi:Celgene: Research Funding. Gomes da Silva:Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: lecture fees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: lecture fees, Institution's payment for consultancy, Travelling support; Celgene: Other: Travelling support; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: lecture fees; Roche: Other: Institution's payment for consultancy, Travelling support; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: lecture fees, Research Funding. Vitolo:Takeda: Speakers Bureau; Sandoz: Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Gilead: Speakers Bureau. Martelli:Sandoz: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; F. Hoffman-La Roche: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Introduction. The majority of SMZLs display an indolent course, however the disease is still incurable and a significant proportion of patients (~25-30%) experience poor outcomes surviving 5 years, and for whom tumor material collected before initiation of medical therapy was available. Mutation analysis was performed by CAPP-seq targeted deep next generation sequencing of tumor genomic DNA. A stringent bioinformatic pipeline was applied to suppress the background noise allowing to call variants with a sensitivity of 5x10-2 in FFPE derived DNA. Copy number variations (CNVs) were identified by using the sequencing reads-based GATK4-CNV algorithm. IGHV rearrangements were obtained by using LymphoTrack® IGH FR1 Assay Panel kit. Molecular clusters were identified by an iterative algorithm that maximizes genetic distinctiveness of subgroups by reassigning patients between clusters that are created a priori based on the co-occurrence of genetic lesions. Relative survival, defined as the ratio between actuarial survival observed in the SMZL cohort and expected survival of the general population matched to patients by geographical origin, sex, age and calendar year of diagnosis, was calculated using the Ederer II method. Results. The analysis included 303 patients with a SMZL diagnosis confirmed on spleen histology. The sample size allowed to identify 30% differences in survival for molecular subgroups comprising at least 5% of cases with a statistical power between 80-100%. Median follow-up was 9.2 years. At 10 years, 85% of patients were alive, consistent with the known indolent behavior of this lymphoma. Genes recurrently affected by non-synonymous somatic mutations in >10% of SMZL included KLF2 (24%), NOTCH2 (19%), KMT2D (15%), TNFAIP3 (13%), EP300 and TP53 (10%). Deletion 7q was documented in 25% of cases and IGHV1-2*04 usage in 32%. By cluster analysis, three major molecular subgroups were identified, each of them characterized by a NOTCH pathway mutated gene (Fig. 1A). The first cluster was defined by NOTCH2 and/or KLF2 mutations and was enriched in TNFAIP3 mutations and IGHV1-2*04 gene usage (Fig. 1A). The second cluster was defined by SPEN mutations, and was enriched in KMT2D and other epigenetic gene mutations (Fig. 1A). The third cluster was enriched in NOTCH1 mutations (Fig. 1A). By relative survival analysis, the NOTCH2/KLF2 cluster showed a lower survival compared to the matched general population, indicating a significant impact of the disease on patients' expected survival (Fig. 1B). Conclusions. The large sample size and inclusion of SMZL confirmed by spleen histopathology review allowed for precise estimation of the prevalence of KLF2 and NOTCH2 mutations in this lymphoma. Three molecular clusters were identified in SMZL, each of them containing a NOTCH pathway gene, supporting the relevance of NOTCH signaling in the pathogenesis of SMZL. Patients belonging to the NOTCH2/KLF2 cluster had a lower relative survival compared to the matched general population. Disclosures Traverse-Glehen: Astra Zeneca: Other: Travel; Takeda: Research Funding. Gomes da Silva:Roche: Other: Institution's payment for consultancy, Travelling support; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: lecture fees; Celgene: Other: Travelling support; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: lecture fees, Institution's payment for consultancy, Travelling support; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: lecture fees; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: lecture fees, Research Funding. Ladetto:Celgene: Honoraria; Jannsen: Honoraria; Acerta: Honoraria; Abbvie: Honoraria; Sandoz: Honoraria; Roche: Honoraria. Rambaldi:Pfizer: Consultancy; Novartis: Consultancy; Omeros: Consultancy; Italfarmaco: Consultancy; Amgen Inc.: Consultancy; Roche: Consultancy; Celgene: Consultancy. Vitolo:Takeda: Speakers Bureau; Sandoz: Speakers Bureau; Gilead: Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Zinzani:MSD: Honoraria, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SERVIER: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; Verastem: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: 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; Astra Zeneca: Speakers Bureau. Gaidano:Roche: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Morphosys: Honoraria; Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Salles:Servier: Honoraria; Abbvie: Honoraria; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria; Amgen: Honoraria; BMS: Honoraria, Other: Advisory Board; Celgene: Honoraria, Other: Advisory Board, Research Funding; Acerta: Honoraria; Janssen: Honoraria, Other: Advisory Board; Merck: Honoraria; Pfizer: Honoraria; Morphosys: Honoraria; Gilead: Honoraria, Other: Advisory Board; Epizyme: Honoraria; Servier: Honoraria, Other: Advisory Board; Takeda: Honoraria. Zucca:Celltrion: Consultancy; AstraZeneca: Consultancy.

Background and aims. In CLL, TL has been associated to outcome. However a larger patient sample and an analysis on a blinded validation series are required to fully establish the independent prognostic value of TL and to define its impact on prognostic subgroups defined according to established predictors. These issues have been addressed on a CLL learning cohort and validated on an independent blinded cohort, overall accounting for 401 CLL patients. Also, we have tested TL as a risk factor of Richter’s Syndrome (RS), an extremely severe event that most of the currently available biomarkers fail to predict. Methods. The learning series (LS) included 191 patients from the university of Torino (UT), while the blinded validation series (BVS) included 210 patients from University of Eastern Piedmont (UEP). TL was assessed on PBMC collected at diagnosis by Southern blotting and no biological or clinical feature of BVS patients was available to the laboratory performing the analysis. Detailed clinical history, clinical parameters at diagnosis as well as VH-mutational status, cytogenetics, CD38 expression and Zap-70 were available for the vast majority of patients and employed together with TL as covariates for multivariate survival analysis. Results. The two series showed no differences for any clinical and biological features except age that was slightly higher in the BVS series. Also TL distribution was similar in the two series (median TL 6024 and 5959 bp respectively). By applying ROC analysis and Youden’s index to the LS we identified a cut-off point of 5000bp segregating 26% (104/401) of patients in the high-risk subgroup. TL was a powerful and independent outcome predictor for both TFS (24.6 vs 73 months p65 years, p65 years (p=.004), Binet stage B-C (p Conclusions. These results demonstrate that TL is a powerful independent predictor of multiple outcome events in CLL and contributes to refine the prognostic assessment of CLL when utilized in combination with other prognostic markers. We thus recommend a more widespread use of this biomarker in CLL. Figure Figure

Objective. The aim of this study was to evaluate whether reappearance of polymerase chain reaction (PCR) positivity for the Bcl-2/IgH translocation following a phase of molecular remission in autografted follicular lymphoma (FL) patients is always associated with reappearance of the original neoplastic clone. Patients and methods. The molecular follow-up of 119 autografted Bcl-2/IgH positive patients was evaluated by nested PCR. In case of molecular recurrence, direct sequencing of involved rearrangements has been performed both at diagnosis and at the time of recurrence. The two sequences then were compared in terms of breakpoints, N insertions, and JH usage. Results. Seventy-five patients achieving molecular remission were identified in our patient sample (63%). Of these patients, eight (10.6%) experienced molecular recurrence. Direct sequencing of the Bcl-2/IgH translocation performed at diagnosis and recurrence showed identical rearrangements in six subjects and unrelated rearrangements in two. As opposed to most true molecular relapses, unrelated rearrangements always occurred several years after transplantation. To date, the two subjects carrying unrelated rearrangements show no signs of active lymphoproliferative disease. Conclusions. This report is the first evidence that Bcl-2/IgH rearrangements unrelated to the original tumor clone can lead to false-positive results during the molecular follow-up of autografted FL patients. Based on these results, we recommend confirmation by direct sequencing, at least for patients experiencing molecular relapse 2 or more years after the end of treatment. This will be particularly important for patients enrolled in clinical trials that schedule additional treatment in case of molecular evidence of persistent disease activity.

Single-center experiences have shown that intensified treatments with autologous transplantation are a promising therapeutic strategy for patients with high-risk follicle-center lymphoma (FCL) at diagnosis, whereas data from prospective multicenter trials are still lacking. This paper describes the results of a prospective multicenter study of an intensified purging-free high-dose sequential (i-HDS) chemotherapy schedule with peripheral blood progenitor cell (PBPC) autografting. The main feature of this program is harvesting stem cells after intensified chemotherapeutic debulking, with no ex vivo manipulation of PBPCs. Ninety-two previously untreated patients aged 60 or younger with advanced-stage FCL were enrolled by 20 Italian centers and evaluated on an intention-to-treat basis. i-HDS proved feasible with limited toxicity (87% patients completed the planned treatment schedule). i-HDS led to a complete remission rate of 88%. The projected overall survival and disease-free survival (DFS) were, respectively, 84% and 67% at 4 years. Centralized molecular analysis showed that polymerase chain reaction-negative harvests could be collected in 47% of cases. Following autograft, 65% of molecularly evaluable patients achieved clinical and molecular remission. The projected DFS at 4 years of this subgroup is 85%. This result emphasizes the importance of achieving maximal tumor reduction in these patients. In conclusion, our data show that highly effective intensified treatments can now be routinely offered to young patients with poor-risk FCL even at small institutions, with no need for sophisticated and expensive cell manipulation procedures.

Several infectious agents appear to provide a proliferative signal -- “antigen-drive” – that could be implicated in the pathogenesis of various type of Non-Hodgkin Lymphoma (NHL). A classical model of infection-driven lymphoprolipherative disorder is Helicobacter pylori-induced gastric MALT lymphoma, where antibiotic therapy allows eradication of both the infectious agent and the clonal B-cell expansion; following the footsteps of these example, several retrospective studies have found a correlation with other pathogens and B-cell Lymphomas, adding new important informations about pathogenesis and laying the groundwork for chemotherapy-free treatments.Although no clear association with infectious agents has yet been identified for Follicular Lymphoma (FL), a growing number of biological and clinical observations suggests that interaction with physiological and pathological microbial populations might play a role also in this subtype of lymphoma: in the last years epidemiological studies investigating the association of known risk factors and FL found a potential correlation with viral or bacterial infections; moreover recent findings about the stimulation of FL clones support the importance of microbial exposure to lymphomagenesis and disease progression.In the following review we make an attempt to find tangible evidences in favor of a role of either physiological and pathological exogenous microbial species in the pathogenesis of FL, and try to integrate the findings coming from epidemiological, biological and interventional studies to define future novel treatment and prevention strategies for FL.

Background: The combination of rituximab (R, 375 mg/m2 intravenously [IV], day 1), bendamustine (B, 70 mg/m2IV, days 2 and 3), and cytarabine (800 mg/m2, IV on days 2 to 4) was highly active in patients with mantle-cell lymphoma (MCL) in a phase 2 study [R-BAC; Visco et al, JCO 2013]. This regimen was well tolerated, but hematologic toxicity was quite relevant, especially in terms of transient grade 3 to 4 thrombocytopenia (76% of cycles). Aiming at reducing hematologic toxicity, the Fondazione Italiana Linfomi (FIL) designed a phase 2 trial adopting the R-BAC schedule, but lowering cytarabine dose to 500 mg/m2 (RBAC500). Materials and Methods: Patients with newly diagnosed MCL, aged 61 to 80 years, not eligible for autologous transplant and fit according to the comprehensive geriatric assessment, were enrolled. Patients presenting with non-nodal leukemic disease were excluded. The primary endpoints were complete remission rate (CR) measured by FDG-PET according to Cheson criteria 2007, and safety. Secondary endpoints included rate of molecular response (MR) by nested-PCR using patient specific IGH or BCL1 based targets, progression-free (PFS) and overall survival (OS). The study was conducted according to the Bryant and Day two-stage design. Results: From May 2012 to February 2014, 57 patients with MCL from 29 centers were recruited and treated. Central pathology revision was performed in 87% of cases. Median age was 71 years (range 61-79), 75% were males, and 91% had Ann Arbor stage III/IV disease. Mantle Cell International Prognostic Index (MIPI) was low in 15%, intermediate in 40%, high in 45%, Ki-67 was ≥30% in 31%, and 9% had the blastoid cytological variant. Overall, 53 patients (91%) received at least 4 cycles, while 36 (63%) had 6 cycles (median 5.3 cycles per patient). Fifteen patients (26%) discontinued treatment before reaching cycle 6 because of toxicity/adverse events, that mainly consisted of prolonged hemato-toxicity between cycles. Only one patient discontinued due to progressive disease. Grade 3 or 4 neutropenia and thrombocytopenia were observed in 49% and 52% of administered cycles, respectively. Febrile neutropenia occurred in 6% of cycles. Extra-hematologic toxicity was mainly cardiac (5%). Overall response rate was 96%, and CR was 93%. The MR rate at the end of treatment was 76% on peripheral blood and 55% on bone marrow (BM) samples. With a median follow-up of 34 months (28-52), the 2-years PFS (± confidence interval) was 81%±5% and the OS 85%±4%. Elevated Ki-67 (≥30%), and the blastoid variant were the strongest independent predictors of adverse PFS. Patients with either of these two features (33%), had a significantly inferior PFS (41% vs 97% after 34 months) compared to patients with classical/pleomorphic variants and low proliferative index (p Conclusions: The R-BAC500 regimen can be safely administered as first line therapy to elderly patients with MCL. Hematologic toxicity is substantially reduced compared to our previous experience. With 93% of FDG-PET negative CR, and a 2-years PFS of 81% without maintenance therapy, the R-BAC500 regimen is a highly effective treatment for patients with MCL, and compares favourably with previously reported regimens in this patient population, including R-bendamustine. Figure 1 Figure 1. Disclosures Visco: Gilead: Speakers Bureau; Lundbeck: Consultancy; Mundipharma: Research Funding; Celgene: Speakers Bureau. Spina:Mundipharma: Membership on an entity's Board of Directors or advisory committees, Other: Speaker Fee; Teva Pharmaceuticals Industries: Membership on an entity's Board of Directors or advisory committees, Other: Speaker Fee. Di Rocco:Celgene: Honoraria. Carella:Millenium: Speakers Bureau; Genentech: Speakers Bureau. Vitolo:Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria; Gilead: Honoraria; Celgene: Honoraria.

Background. Mantle Cell Lymphoma (MCL)represents an aggressive lymphoma for which an effective treatment has still to be determined. The FIL-MCL0208 phase III trial (EudraCTNumber: 2009-012807-25) is exploring R-CHOP followed byi) high-dose cytarabine, autologous stem cell transplantation, and ii) randomization between lenalidomide maintenance vs observation (Cortelazzo et al, EHA 2015). We performed genome-wide DNA profiling to identify unbalanced copy number variations (CNVs) with a clinical significance in patients enrolled in the FIL-MCL0208 phase III trial. Patients and Methods. The study included untreated, advanced stage MCL patients ( Results. 161 patients were currently evaluable for CNVs and clinical outcome. Patients had an intermediate/high-risk MIPI and a Ki67 ³ 30% in 43% and 42% of the cases, respectively. Twenty-five recurrent unbalanced CNVs were defined (Table 1). By multiple test corrected univariate analysis, seven CNVs had a negative impact on PFS: +3, 7p gain, 9p loss (CDKN2A), 17p loss (TP53), 8p loss, and 2 losses at 22q (Table 1). MIPI (intermediate/high vs low risk), Ki67+ and the TP53/KMT2D model (Rossi et al, ASH 2015) were also statistically significant. Combining CNVs and mutations, TP53 was inactivated in 27/147 cases (18%): mutated/deleted in 7/147 (5%), deleted but not mutated in 14/147 (10%), and mutated but not deleted in 6/147 (4%). The negative prognostic impact was equal for all the 3 inactivation modalities, which were then considered as a single group for further analyses. ATM was inactive in 69/147 (47%): mutated/deleted in 24/147 (16.3%), deleted in 12/147 (8%), and mutated in 33/147 (22.4%). KMT2D (MLL2) was inactive in 18/147 (12%): mutated/deleted in 1/147 ( The lesions with a significant impact at univariate were included in a multivariate analysis alongside MIPI, KMT2D inactivation and Ki67+ as continuous variable. Only TP53 inactivation by deletion and/or mutation, 7p22.2-p12.1 gain and KMT2D inactivation maintained their independent prognostic significance. Conclusions. Genome wide DNA profiling in the FIL-MCL0208 phase III trial identified lesions, namely TP53 and KMT2D inactivation and gains at 7p, which maintain a poor outcome significance in young MCL patients even following high-dose cytarabine and autologous stem cell transplantation. Disclosures Rossi: Gilead: Honoraria, Research Funding; Abbvie: Honoraria; Janseen: Honoraria. Stelitano:Azienda Ospedaliera: Employment. Gaidano:Janssen: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Gilead: Consultancy, Honoraria, Speakers Bureau; Morphosys: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria.

Background: Limited data exist to describe the clinical features and outcomes for elderly pts with FL. The FLASH group performed a prospectively planned pooled analysis of IPD from first-line RCTs and examined associations between age ( 70 years), clinical characteristics and FL outcomes. Methods: We identified 18 randomized controlled multicenter clinical trials in the FLASH database which enrolled elderly pts (> 70 yrs). From these 18 studies, 5922 previously untreated FL pts were included for this analysis. Complete response (CR) at 24 and 30 months were defined as whether the pt achieved and remains in CR at 24 months and 30 months after initiation of induction treatment. PFS24 is defined as proportion of pts progression-free and alive at 24 months post-randomization. Time to progression (TTP) and overall survival (OS) were defined as time from randomization to the date of progression (censoring for death without progression) and date of death due to any cause, respectively. Progression-free survival (PFS) was defined as time from randomization to the date of progression or death, due to any cause, whichever comes first. Non-lymphoma death was defined as death without prior progression. Early disease outcomes, i.e. CR24, CR30, and PFS24 were primary outcomes; secondary outcomes were TTP, OS, and PFS. For time-to-event outcomes, Kaplan-Meier method and log-rank test were used for univariate estimation and comparison; stratified Cox proportional hazard modeling was used for multivariable analyses. Cumulative incidence methods were used to model PFS while treating disease progression as the primary event of interest and non-lymphoma death as a competing risk. For binary outcomes, multivariable logistic regression was used to estimate the association between age groups and outcomes. Variable adjusted in the regression models are FLIPI score without the age component, ECOG performance status (>= 2 vs < 2), and rituximab use. Results: Among 5922 previously untreated FL pts from 18 RCTs, 63% (n = 3728) were 70 yrs. Pts age > 70 (vs. = 2 (8.8% vs 5.0%, p = 0.0004), and elevated β2-microglobulin (68% vs 49%, p < 0.001), less often had > 4 lymph nodes involved (54% vs 65%, p < 0.001), and had similar FLIPI scores without age component (p = 0.17). There were no significant differences between groups in: Ann Arbor stage (94% vs 95% stage III/IV) or rituximab use (62% vs 58%). Median survival follow-up was 5.6 yrs. Pts > 70 yrs did not differ from pts 70 and 70 and 70 and 70 with no difference in disease progression (Figure). In regression models, adjusting for rituximab use, ECOG PS >= 2, and FLIPI score without the age component, age > 70 was a significant predictor of OS and PFS (due to higher incidence of non-lymphoma death), but not PFS24, CR24 or CR30 (Table). Conclusions: FL pts > 70 yrs treated on trials have similar early disease outcomes to younger patients. There is no disease-specific outcome difference between age groups. Age alone should not disqualify patients from standard treatments or RCTs. Disclosures Flowers: Genentech: Consultancy, Research Funding; NIH: Research Funding; Mayo Clinic: Research Funding; TG Therapeutics: Research Funding; Millenium/Takeda: Research Funding; ECOG: Research Funding; Acerta: Research Funding; Pharmacyclics, LLC, an AbbVie Company: Research Funding; Roche: Consultancy, Research Funding; AbbVie: Research Funding; Infinity: Research Funding; Gilead: Consultancy, Research Funding. Ou:Mayo Clinic: Employment. Shi:Mayo Clinic: Employment. Hochster:Genentech: Consultancy, Other: Consultancy fees for advisory boards for GI cancer and bevacizumab with amounts within Yale University de minims guidelines. Brice:Roche: Honoraria; Takeda Pharmaceuticals International Co.: Honoraria, Research Funding; Bristol Myers-Squibb: Honoraria; Gilead: Honoraria; Seattle Genetics: Research Funding. Hiddemann:Roche: Other: Grants; Roche: Membership on an entity's Board of Directors or advisory committees; Genentech: Other: Grants. Marcus:Takeda: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau. Kimby:Abbvie: Consultancy, Honoraria; Jansen: Consultancy, Honoraria; Celgene: Honoraria; Baxalta: Consultancy; Gilead: Honoraria. Herold:Gilead: Other: Personal fees from member advisory board; Celgene: Honoraria; Genentech: Other: Grants; Roche: Honoraria, Other: Grants. De Bedout:Celgene: Employment. Nielsen:Hoffmann-La Roche: Employment. Morschhauser:Roche: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Gilead Sciences: Consultancy, Honoraria; Janssen: Honoraria. Rummel:Mundipharma GmbH: Other: Personal fees, Research Funding; Roche Pharma AG: Other: Personal fees, Research Funding. Vitolo:Gilead: Other: Honoraria for lectures; Takeda: Other: Honoraria for lectures; Roche: Membership on an entity's Board of Directors or advisory committees, Other: Honoraria for lectures; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: Honoraria for lectures. Salles:Celgene: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Gilead: Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Roche/Genentech: Consultancy, Honoraria, Research Funding; Mundipharma: Honoraria. Sargent:Celgene: Research Funding.

Immunogenetic analysis of MM has proven instrumental in elucidating disease ontogeny e.g. by revealing the clonal relationship between switch variants expressed by the bone marrow plasma cells and myeloma progenitors in the marrow and blood; demonstrating the marked under-representation of the inherently autoreactive IGHV4-34 gene; and, identifying patterns of somatic hypermutation (SHM) indicative of post-germinal center derivation. Yet, limited information exists about the composition of the immunoglobulin (IG) gene repertoire in MM cases expressing different heavy chain isotype, in particular A versus G. This is relevant in light of studies showing an overall higher SHM impact in CD27+IgA+ compared to CD27+IgG+ normal memory B cells, perhaps reflecting a distinct location of the immune response, especially considering that IgA class switching mostly occurs in mucosa-associated lymphoid tissues. From a clinical perspective, it is also relevant to note that IgA patients exhibit a higher incidence of the t(4;14) translocation, shorter progression-free survival and worse median overall survival compared to IgG patients. Here, we explored potential differences in the immunoprofiles of IgA versus IgG MM focusing on IG gene repertoire and SHM characteristics. In total, 428 patients with a diagnosis of MM following the IMWG criteria from collaborating institutions in Greece, Italy and Spain (n=355) or retrieved from the LIGM-DB (n=73) were included in the study. Of these, 135 and 293 belonged to IgA and IgG MM groups, respectively. Amongst the evaluated productive IG rearrangements, IGHV3 subgroup genes predominated in both groups (IgA: 58.5%; IgG: 52.2%). However, at the individual gene level, major asymmetries were noted, since only 7 IGHV genes accounted for 41.6% of the IgA and 46.7% of the IgG cases, respectively. Of these, 3 genes were shared between IgA and IgG MM cases: IGHV3-30 (IgA: 11.9% - IgG: 13.3%), IGHV3-23 (IgA: 5.2% - IgG: 6.8%) and IGHV3-9 (IgA: 6.7% - IgG: 4.4%), whereas the remaining 4 of the 7 most frequent genes were specific for each group with significant (p Disclosures Terpos: Celgene: Honoraria; Novartis: Honoraria; Genesis: Consultancy, Honoraria, Other: Travel expenses; BMS: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: Travel expenses, Research Funding. Stamatopoulos:Gilead: Consultancy, Honoraria, Research Funding; Abbvie: Honoraria, Other: Travel expenses; Novartis: Honoraria, Research Funding; Janssen: Honoraria, Other: Travel expenses, Research Funding.

We assessed the prognostic value of minimal residual disease (MRD) within the ML17638 phase 3 trial from the Fondazione Italiana Linfomi, investigating the role of rituximab maintenance in elderly follicular lymphoma (FL) patients after a brief first-line chemoimmunotherapy. MRD for the bcl-2/IgH translocation was determined on bone marrow cells in a centralized laboratory belonging to the Euro-MRD consortium, using qualitative and quantitative polymerase chain reactions (PCRs). Of 234 enrolled patients, 227 (97%) were screened at diagnosis. A molecular marker (MM) was found in 51%. Patients with an MM were monitored at 8 subsequent times. Of the 675 expected follow-up samples, 83% were analyzed. Conversion to PCR negativity predicted better progression-free survival (PFS) at all post-treatment times (eg, end of therapy: 3-year PFS, 72% vs 39%; P < .007). MRD was predictive in both maintenance (83% vs 60%; P < .007) and observation (71% vs 50%; P < .001) groups. PCR positivity at the end of induction was an independent adverse predictor (hazard ratio, 3.1; 95% confidence interval, 1.36-7.07). MRD is a powerful independent outcome predictor in FL patients who receive rituximab-intensive programs, suggesting a need to investigate its value for decision-making. This trial was registered at www.clinicaltrial.gov as #NCT01144364.

Although modern treatment strategies are highly effective in many cases of progressive chronic lymphocytic leukemia (CLL), a challenging subgroup of patients show poor response to standard regimens...

Telomere shortening, a well-known marker of aging and cellular stress, occurs under several conditions in the hematopoietic compartment, including aplastic anemia and following iatrogenic noxae. We decided to verify whether pathological telomere erosion also arises in restored Philadelphia-negative (Ph-negative) hematopoiesis following successful treatment of chronic myeloid leukemia (CML). Eighty-one CML patients in complete cytogenetic remission were compared to 76 age-matched healthy subjects. Myeloid cells of CML patients had shorter telomeres than controls (6521 bp vs 7233 bp, p

The role of Vγ9Vδ2 T cells in chronic lymphocytic leukemia (CLL) is unexplored, although these cells have a natural inclination to react against B-cell malignancies. Proliferation induced by zoledronic acid was used as a surrogate of γδ TCR-dependent stimulation to functionally interrogate Vγ9Vδ2 T cells in 106 untreated CLL patients. This assay permitted the identification of responder and low-responder (LR) patients. The LR status was associated with greater baseline counts of Vγ9Vδ2 T cells and to the expansion of the effector memory and terminally differentiated effector memory subsets. The tumor immunoglobulin heavy chain variable region was more frequently unmutated in CLL cells of LR patients, and the mevalonate pathway, which generates Vγ9Vδ2 TCR ligands, was more active in unmutated CLL cells. In addition, greater numbers of circulating regulatory T cells were detected in LR patients. In multivariate analysis, the LR condition was an independent predictor of shorter time-to-first treatment. Accordingly, the time-to-first treatment was significantly shorter in patients with greater baseline numbers of total Vγ9Vδ2 T cells and effector memory and terminally differentiated effector memory subpopulations. These results unveil a clinically relevant in vivo relationship between the mevalonate pathway activity of CLL cells and dys-functional Vγ9Vδ2 T cells.

Abstract 3881 Background: The mutational status of tumor immunoglobulin heavy chain variable region (IGHV) is a reliable prognosticator in chronic lymphocytic leukemia (CLL): patients with unmutated (UM) IGHV have a worse prognosis than patients with mutated (M) IGHV. The tumor microenvironment actively supports the survival of CLL cells and confers a multidrug resistance (MDR) phenotype to CLL cells. MDR is due to the over-expression of membrane transporters, like P-glycoprotein (Pgp), which actively extrudes several anticancer drugs. Pgp is under the positive control of the transcription factor Hypoxia-Inducible-Factor-1-alfa (HIF-1α) which is activated by isoprenylated Ras/Rho-dependent downstream signaling pathways. Ras and Rho isoprenylation are regulated by the mevalonate (Mev) pathway activity suggesting that this pathway can be exploited as a metabolic checkpoint to regulate chemresistance. Aim: The aim of this study was twofold: 1) to investigate the correlation between chemoresistance and the activity of the Mev pathway and Ras/Rho-A downstream signaling pathways in purified M and UM CLL cells under basal conditions and after incubation with stromal cells; 2) to evaluate the chemosensitizing effects of agents specifically targeting the Mev pathway and downstream signaling pathways under the same culture conditions. Methods: M and UM CLL cells were cultured in the presence and in the absence of murine stromal cells (M210B4) and exposed to Zoledronic acid (ZA) (1 μmol/L), Simvastatine (Sim) (1 μmol/L), ERK1/2 kinase inhibitor PD98059 (10 μmol/L), HIF-1α inhibitor YC-1 (10 μmol/L) and Doxorubicine (Doxo) (1 μmol/L). The Mev pathway activity was measured by cells radiolabelling with [14C]-mevalonic acid and thin layer chromatography. Ras, ERK1/2 and Akt activity were detected by Western blot. Rho, Rho Kinase and HIF-1α activity were assessed by ELISA. Mdr1 expression was measured by Real Time-PCR. PgP activity was evaluated by measuring Doxo intracellular accumulation. Doxo cytotoxicity was assessed by annexin V and propidium iodide staining. Results: The Mev pathway is significantly more active in UM than in M CLL cells. This hypermetabolic activity translates into a higher activation of Ras/Akt and Rho/Rho kinase signaling pathways and higher expression of the phosphorylated active form of HIF-1α. HIF-1α activation positively regulates mdr1 gene expression in UM CLL cells leading to a more effective Doxo extrusion and therefore better survival upon Doxo exposure. M210B4 stromal cells further protect UM CLL cells from Doxo induced cell death by upregulating Mev pathway activity, HIF-1α/mdr1/PgP axis activation, and Doxo extrusion. Targeting the Mev pathway of UM cells with ZA and Mev reduces the basal activity of HIF-1α/mdr1/PgP axis and significantly increases Doxo retention and cytotoxicity. Similar effects are obtained with PD85 and YC1–10 which are specific inhibitors of the downstream molecules ERK-1/2 and HIF-1α, respectively. All these agents are able to overcome the protective effect exerted by stromal cells by significantly increasing PgP activity and Doxo-induced cell death. Conclusions: Our data demonstrate that the Ras- and Rho-dependent HIF-1α/mdr1/PgP axis is more active and associated with higher levels of MDR in UM compared with M CLL cells. Targeting the Mev pathway and/or downstream signalling pathways is a promising strategy to circumvent basal and stroma-mediated chemoresistance especially in UM CLL cells. Disclosures: Massaia: Novartis Farma S.p.A: Honoraria, Research Funding.

Background Characterization of the immunoglobulin gene repertoire has improved our understanding of the immunopathogenesis of lymphoid tumors. Early B-lymphocyte precursors of multiple myeloma are known to exist and might be susceptible to antigenic drive. Design and Methods To verify this hypothesis, we collected a database of 345 fully readable multiple myeloma immunoglobulin sequences. We characterized the immunoglobulin repertoire, analyzed the somatic hypermutation load, and investigated for stereotyped receptor clusters. Results Compared to the normal immunoglobulin repertoire, multiple myeloma displayed only modest differences involving only a few genes, showing that the myeloma immunoglobulin repertoire is the least skewed among mature B-cell tumors. Median somatic hypermutation load was 7.8%; median length of complementarity determining-region 3 was 15.5 amino acids. Clustering analysis showed the absence of myeloma specific clusters and no similarity with published chronic lymphocytic leukemia or lymphoma subsets. Conclusions Analysis of multiple myeloma immunoglobulin repertoire does not support a pathogenetic role for antigen selection in this tumor.

Role of interim-PET (I-PET) in diffuse large B-cell Lymphoma (DLBCL) is controversial. To determine predictive value of I-PET on progression-free survival (PFS), we enrolled 88 first-line DLBCL patients treated with 6-8 R-CHOP courses regardless of I-PET. PET/CT were performed at diagnosis, after 2 to 4 courses and at the end of therapy with central reviewing according to visual dichotomous criteria. Results are as follows: I-PET, 72% negative, 28% positive; final-PET (F-PET), 88% negative, 12% positive; clinical complete response 90%. Concordance between clinical response and F-PET negativity was 97% because of 2 false positive. With a median follow-up of 26.2 months, 2-year overall survival and PFS were 91% and 77%, respectively. Two-year PFS for I-PET and F-PET negative versus positive were as follows: I-PET 85% versus 72% (P = .0475); F-PET 83% versus 64% (P < .001). Because of a small number of events, 2 independent bivariate Cox models were tested for PFS. In model 1, F-PET contradicted I-PET (hazard ratio [HR] = 5.03, P = .015 vs 1.27, P = 691); in model 2, F-PET (HR = 4.54) and International propnostic Index score (HR = 5.36, P = .001) remained independent prognostic factors. In conclusion, positive I-PET is not predictive of a worse outcome in DLBCL; larger prospective studies and harmonization of I-PET reading criteria are needed.

Abstract 3653 Background. The rearrangement Bcl2/IgH is detectable by PCR in more than half of patients with follicular lymphoma. Different authors reported on the long-term prognostic impact of the persistence of this rearrangement (minimal residual disease or MRD). In this study, we report about MRD significance in 534 patients randomized to receive 8 doses of Rituximab associated with 8 cycles of CVP, or 6 cycles of CHOP or FM, and no maintenance in the context of the Fondazione Italiana Linfomi (FIL) multicenter phase-III “FOLL05” trial (NCT00774826). Patients and methods. For qualitative PCR analysis, samples were centralized. Quantitative assays were performed by the 4 laboratories of the “FIL MRD NETWORK”. Qualitative and quantitative PCR were performed according to the Euro-MRD guidelines. Results. At baseline, 424 out of the 504 patients enrolled were assessed for Bcl2/IgH and 223 (52,6%) were Bcl2/IgH positive (molecular marker=MM). No significant differences were detected between cases with and without molecular assessment at the enrollment or after therapy, and those with positive or negative MM for the main clinical and prognostic features, and for treatment allocation. At the first time-point (within 6 weeks after the end of therapy), 153 of the 223 cases PCR-positive at enrollment were re-assessed: 110 (69,6%) achieved PCR negativity. MRD was not significantly correlated to clinical features or quality of clinical response. Three-year PFS was better for patients achieving PCR negativity at the sixth week than those retained MM (69% vs 50%), but this difference was not statistically significant. On the contrary, PFS was significantly conditioned by the PCR status at 12 and 24 months (87 and 66 cases evaluable), with 3-year PFS of 66% for cases PCR-negative versus 41% for those PCR-positive at 12 months (p=0.015, see Figure 1), and 84% vs 50% (p=0.014) at 24 months. Moreover, the probability of being PCR-negative by 24 months was significantly lower for cases receiving R-CVP (18% vs 41% in the R-CHOP and 41% in the R-FM, p=0.035). PCR-negativity resulted in better PFS both in CR and in PR patients (3-year PSF=72% for cases CR/PCR- vs 32% for those CR/PCR+ vs 62% for those PR/PCR- and 25% for patients in PR/PCR+; p=0.001). When PCR negativity in patients with or without complete response and PCR negativity by 12 months were considered in a multivariate analysis together with performance status, FLIPI, response, and age, the PCR negativity retained its favorable impact on PFS (HR=-1.2, 95% CI:0.32–0.19, p=0.001). Finally, in 105 cases tumor burden at the diagnosis was assessed by quantitative PCR. The median value was 3 × 10−3 copies; cases displaying values 1 × 10−4 copies p=0.015). A significant MRD clearance was observed at the end of therapy: the mean value of Bcl2/IgH was 2 × 10−1 copies before therapy versus 5 × 10−3 at the first time-point. No differences in the entity of the MRD clearance were observed according to the arm of treatment. Conclusions. In conclusion, this study shows that R-CHOP and R-FM are more effective to clear MRD in follicular lymphoma compared to R-CVP. Moreover, the most prominent impact on PFS is exerted by the molecular status detected at least 6 months after the end of therapy. This observation is in line with the hypothesis of a quite slow, but long-term sustained, MRD clearance exerted by rituximab-based therapies. Finally, this study shows that patients with Disclosures: No relevant conflicts of interest to declare.

Abstract 3878 Introduction: In this study, a serological proteome analysis (SERPA) was applied for the first time to identify novel tumor-associated antigens (Ags) capable of eliciting humoral immune responses in patients with chronic lymphocytic leukemia (CLL). SERPA has been demonstrated to be a valuable method to identify tumor associated Ags in several human solid and hematological malignancies. The identification and characterization of circulating antibodies (Abs) and corresponding Ags in CLL can provide useful information to understand cell transformation, predict clinical outcome, and develop immune-based interventions. Methods: SERPA was performed in 21 untreated patients. Proteins extracted from purified CLL cells were separated by 2-D electrophoresis (2-DE) to obtain proteomic maps which were blotted with corresponding sera by Western Blot to reveal Ab-based reactivity with autologous proteins. To verify the CLL specificity of Abs recognition, 7 out of 21 maps were also probed with sera collected from 7 healthy donors (HD). For identification, Ag spots in WB were aligned with proteins in 2-DE maps. The protein spots corresponding to the assigned Ags were excised from the gel, trypsin digested and analyzed by peptide mass fingerprint by MALDITOF Mass Spectrometry (MS) with the software MASCOT. T cells from 6 CLL patients and 3 HD were stimulated with autologous ENOA-pulsed and control dendritic cells (DC) and evaluated by IFNγ ELISPOT assay. Ags surface expression was analyzed by flow cytometry. Statistical correlations were performed using t-test, Mann-Withney rank sum test and χ2-test. Results: Sixteen out of 21 CLL sera (76%) were immunoreactive and produced a total number of 45 Ag spots, whereas HD sera produced only 3 spots (p Statistical correlation analyses showed that immunoreactive CLL patients are characterized by an early stage of disease. Moreover, ENOA-reactive patients have a better preserved immune system because they have higher numbers of CD3+ (p=.02), CD3+/CD4+ (p=.03) and CD3+/CD8+ (p=.05) cells in the peripheral blood than ENOA-unreactive patients. We also investigated the possibility to induce ENOA-specific T-cell immune responses in 6 CLL patients. ENOA-pulsed DC induced IFNγ production in 4/6 patients (66%). The response was ENOA and CLL specific because: 1) it was not induced by unpulsed DC or DC pulsed with an irrelevant protein; 2) it was not induced when T cells from 3 HD were stimulated with autologous ENOA-pulsed DC. Interestingly, ENOA Abs were detectable by SERPA in 3 out of 4 (75%) patients with ENOA-induced T-cell responses, whereas they were undetectable in patients with unresponsive T cells. Correlations with the IGHV mutational status showed that all patients with ENOA-reactive T cells were M. Conclusions: These results indicate that ENOA is able to elicit specific humoral and cellular immune responses suggesting that this protein can be a promising biomarker and a potential target for immunotherapy in CLL. Disclosures: Massaia: Novartis Farma S.p.A: Honoraria, Research Funding.

Introduction: we previously reported (Vitolo U, JCO 2013) the results of a randomized study with brief first-line chemoimmunotherapy followed by rituximab maintenance vs observation. With a median follow-up of 42 months, 3-year Progression Free Survival (PFS) and Overall Survival (OS) were 66% and 89%, respectively. The addition of Rituximab maintenance gave a benefit to the patients: 2-year PFS was 81% for rituximab maintenance versus 69% for observation with a HR of 0.63 (95% CI: 0.38-1.05, p=0.079), although not statistically significant. Moreover we also found that achievement of Minimal Residual Disease (MRD) negativity predicted a better PFS: 3-year PFS 72% vs 39%, HR 3.1 (Ladetto M, Blood 2013). Overall these data showed the good efficacy of this brief chemoimmunotherapy regimen in elderly FL patients. Aim of this analysis was to report long-term outcome and long-term toxicities of this regimen. Methods: From January 2004 to December 2007, 242 treatment-naive patients aged 60-75 years with FL Grade I, II and IIIa were enrolled by 33 FIL centres. Patients had to have advanced (high tumor burden stage II or stage III-IV) disease requiring treatment: 4 monthly courses of R-FND (standard doses of Rituximab, Fludarabine, Mitoxantrone, Dexamethasone) every 28 days followed by 4 weekly Rituximab infusions as consolidation. Responders patients [complete remission (CR) + unconfirmed CR + partial remission (PR)] were randomized to brief rituximab maintenance (Arm A), once every 2 months for a total of 4 doses, or observation (Arm B). MRD for the bcl-2/IgH translocation was determined on bone marrow cells in a centralized laboratory belonging to Euro-MRD consortium, using qualitative and quantitative PCR. Results: a total of 234 patients began chemoimmunotherapy: after induction and consolidation treatment overall response rate was 86%, with 69% CR. Of these, 210 completed the planned treatment and 202 responders were randomized. Up to date, median follow-up were 96 months from enrollment and 87 months from randomization; additional follow-up data were available for 127/146 (87%) not relapsed/progressed patients. Five- and 7-year PFS for the whole population were 57% and 51%, respectively; 5- and 7-year OS for the whole population were 85% and 80%, respectively. From enrollment, an advantage in term of PFS and also OS was observed in FLIPI low risk patients: 7-year PFS was 67% for low risk versus 38% for intermediate-high risk patients (p Conclusions: the present long-term results of this trial with a prolonged follow-up of 7 years confirm that a good outcome is achievable in elderly FL patients with a short-term chemoimmunotherapy (R-FND + Rituximab consolidation) with a 7-year PFS of 51% and low toxicity. In addition these results did not show clear evidence in favor of a shortened Rituximab maintenance after R-fludarabine containing chemotherapy. Conversely, the achievement of PCR negativity maintains predictive value for a better outcome. Figure 1. Figure 1. Disclosures Off Label Use: Rituximab maintenance was not licensed in first-line treatment for follicular lymphoma at that time in Italy; Rituximab was provided free by Roche.

Background. Recently, the somatic MYD88L265P mutation has been found as the hallmark of Waldenström Macroglobulinemia (WM), being detectable in nearly 90% of cases, as well as in up to 50% of IgM MGUS, rarely in other non-Hodgkin lymphomas and never in multiple myeloma (MM). Beyond its potential diagnostic role, this mutation has been associated with tumor growth and therapy resistance. Moreover, MYD88L265P might represent an ideal marker for minimal residual disease (MRD) monitoring in a disease whose therapeutic scenario has been rapidly changing, with many new available and highly effective drugs (nucleoside analogues, proteasome and BTK-inhibitors). However, the current MYD88L265P allele-specific quantitative PCR (ASqPCR) diagnostic tool lacks sensitivity (1.00E-03) and thus is not suitable for MRD. Moreover, is not useful to test peripheral blood (PB), that harbors low concentrations of circulating tumor cells (especially after immunochemotherapy), neither to assess cell-free DNA (cfDNA), usually present at very low amount in plasma. Therefore, our study aims: 1) to assess whether a highly sensitive tool as droplet digital PCR (ddPCR) might be helpful in MYD88L265P screening; 2) to evaluate whether MYD88L265P might be a suitable marker for MRD monitoring in WM. Methods. Bone marrow (BM) and PB samples were collected at diagnosis and during follow-up from a local series of patients affected by WM, IgM MGUS and IgG-secreting lymphoplasmacytic lymphoma (LPL), as well as samples from healthy subjects and MM were used as negative controls. Genomic (gDNA) and cell-free DNA (cfDNA) were extracted as recommended (Qiagen). MYD88L265P was assessed on 100 ng of gDNA by ASqPCR as previously described [Xu 2013] and by ddPCR, using a custom dual labelled probe assay (Bio-Rad). When available, 50 ng of cfDNA were tested for MYD88L265P, only by ddPCR. ddPCR was performed on 20 µl of reaction at 55°C for 40 cycles, run on QX100 droplet reader and analyzed by QuantaSoft v1.6.6 (Bio-Rad). MYD88L265P ASqPCR level was estimated as described [Treon 2012]. ΔCT Results. Once the ddPCR assay was optimized, the sensitivity of MYD88L265P ddPCR was compared to ASqPCR on a ten-fold serial dilution standard curves built with a 70% MYD88L265P mutated WM sample, previously identified by Sanger sequencing [Treon 2012]. Whereas ASqPCR confirmed the reported sensitivity of 1.00E−03, ddPCR reached a sensitivity of 5.00E−05. Thereafter, overall 105 samples (48 BM, 57 PB, 52 diagnosis and 53 follow up) from 58 patients (49 WM, 5 IgM MGUS and 4 LPL) as well as 20 controls (15 healthy subjects and 5 MM) were tested by both methods. 32/33 (97%) diagnostic BM scored positive for MYD88L265P by both ddPCR and ASqPCR (being the only one negative a WM), while ddPCR, was able to detect more mutated cases, than ASqPCR, among diagnostic PB samples: 15/19 (79%) vs 9/19 (47%) (Table1). Moreover, to investigate whether the MYD88L265P ddPCR tool could be used for MRD detection we compared it to the standardized IGH-based MRD. An IGH-based MRD marker was found in 40/53 (75%) patients (37 WM and 3 LPL). Five Patients, so far analyzed, with baseline and follow up samples (18 BM, 5 PB) showed highly superimposable results between the two methods. Finally, pivotal results on cfDNA from 10 patients showed higher median levels of MYD88L265P mutation in plasma if compared to PB. Conclusions. We developed a new tool for diagnosis and MRD monitoring in WM, showing that: 1) ddPCR is a highly sensitive tool for MYD88L265P detection, especially useful in low infiltrated samples, like PB; 2) MYD88L265P can be effectively and easily used for MRD monitoring in WM, achieving similar results to standardized IGH-based MRD; 3) cfDNA recovered from plasma might be an attractive alternative for MYD88L265P detection, deserving further investigation. Methodological validation against IgH-based MRD detection and Flow cytometry and correlations with clinical impact are currently ongoing on external samples series. Table 1.PATIENTSWM (45)LPL (2)IgM MGUS (5)TISSUEBMPBBMPBBMPBSAMPLES31141114MYD88L265P ddPCR/ASqPCR30/3011/71/10/01/14/2 TABLE 1. MYD88L265P mutation detection in diagnostic samples: ddPCR vs ASqPCR Disclosures Boccadoro: Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Onyx Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Background. Recent studies have described the landscape of recurrently mutated genes in mantle cell lymphoma (MCL), including genes involved in DNA damage response/cell cycle (ATM, TP53, CCND1), epigenetic regulation (KMT2D also known as MLL2, WHSC1), and cell signaling (BIRC3, TRAF2, NOTCH1). However, with the exception of TP53 abnormalities, little is known about the clinical relevance of recurrent mutations in MCL. Thus, we performed deep sequencing analysis of a MCL gene panel in the prospective series of patients enrolled in the ongoing FIL-MCL0208 phase III trial (EudraCTNumber: 2009-012807-25). Patients and Methods. The study included untreated, advanced stage 70% of cases. The gene panel was analyzed in tumor DNA from baseline bone marrow CD19+ purified MCL cells and, for comparative purposes to filter out polymorphisms, in the paired normal genomic DNA (available in 55% of cases) using a TruSeq Custom Amplicon target enrichment system followed by deep next generation sequencing (Illumina, median depth of coverage 2356x). Variants represented in >10% of the alleles were called with VarScan2 with the somatic function when the paired germline DNA was available. For patients lacking germline DNA, a bioinformatic pipeline including a number of stringent filters was applied to protect against the misclassification of polymorphisms as somatic variants. Primary endpoint of the analysis was progression free survival (PFS). Results. Out of the enrolled patients, 151 are currently evaluable for mutations and clinical outcome (median age: 57 years, range 35-66; males 75%). Among prognostic factors, the MIPI was intermediate or high-risk in 49% of patients, the Ki67 ≥30% in 39%, and blastoid histology occurred in 8%. At the first planned interim analysis, median follow-up of alive patients was 26 months. At 2-years, 79% of patients were progression free and 91% alive (Cortelazzo et al EHA 2015). Overall, at least one mutation was detected in 106/151 cases (70%), including mutations of ATM in 42% of cases, CCND1 in 14%, WHSC1 in 13%, KMT2D in 12%, TP53 in 7%, NOTCH1 in 6%, BIRC3 in 5% and TRAF2 in 1% (Figure 1A). By univariate analysis, mutations of TP53 (2-years PFS 48% vs 82%; p Conclusions. Though limited by the short follow-up, our data show that: i) the combination of two genetic biomarkers (i.e. TP53 and KMT2D mutations) allows to predict the benefit that young MCL patients can gain from a cytarabine-based high dose sequential chemotherapy followed by autologous stem cell transplantation; ii) intensive chemotherapy does not overcome the negative prognostic impact of TP53 mutations; and iii) KMT2D mutations may represent a novel genetic biomarker in MCL patients. Figure 1. Figure 1. Disclosures Santoro: Celgene: Research Funding.

Introduction. Relapsed and primary refractory peripheral T-cell lymphomas (PTCL) show a dismal outcome, with a 5-year overall survival of only 30%. There is no standard salvage chemotherapy for these patients. Gemcitabine was proved to be an effective monotherapy, yelding 60-70% overall response rates in patients with advanced heavily pre-treated disease. Romidepsin, a histone deacetylase inhibitor recently approved by Food and Drug Administration, has demonstrate an overall response rate (ORR) of 30% and a complete response (CR) rate of 16%. We have recently designed a multicentric trial to investigate the role of the combination of gemcitabine plus romidepsin (GEMRO regimen) in relapsed or refractory PTCL, looking for a potential synergistic effect of the two drugs. Methods. Twenty relapsed/refractory PTCL patients were included in a multicentric, prospective phase II trial which contemplated an induction with romidepsin 12 mg/m2 intravenously (i.v.) on days 1, 8, 15, and gemcitabine, 800 mg/m2 i.v. on day 1 and 15, for 6 cycles, each cycle to be repeated every 28 days. After the induction phase, patient who obtained at least a partial remission (PR) proceeded onto romidepsin maintenance at the dose of 14 mg/m2 i.v. until disease progression. The primary endpoint was to evaluate the efficacy of GEMRO regimen after the induction phase, as assessed by complete response (CR) rate; safety assessment was regarded as a secondary objective. The trial was registered under EudraCT (2012-001404-38). Results. Twenty patients have been recruited for this study. At present time, all patients underwent the induction phase and are evaluable for response and toxicity. The median age of patients was 55 years (range, 24-77). According to histology, 10 patients had PTCL not otherwise specified, 9 had an angioimmunoblastic T-cell lymphoma, 1 had a kinase negative anaplastic large cell lymphoma. The median number of prior therapies was 2 (range, 1-4); 7/20 (35%) patients had failed a prior stem cell transplant. Nineteen out of 20 (95%) patients presented with advanced stage. At the end of induction phase, the ORR was 31% including 2 CRs and 3 PRs. One of the 2 CR patients discontinued the treatment after 4 cycles due to cardiac toxicity, however maintaining a continuous CR with a follow up of 2 years. The other CR patient is still on treatment in maintenance phase. Grade ≥3 adverse events were represented by thrombocytopenia (60%), neutropenia (50%), and anemia (20%). Conclusions. To date, data failed to show a superiority of the GEMRO combination regimen over single agent romidepsin as salvage therapy for refractory or relapsed PTCL patients. More mature data and an adequate follow-up will be required to better understand the role of this combination regimen. Disclosures Zinzani: Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; J&J: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Background. The aggressive clinical behavior of mantle cell lymphoma (MCL) is attributed to specific genetic and molecular mechanisms involved in its pathogenesis, mainly the t(11;14)(q13;q32) traslocation and cyclin D1 (CCND1) overexpression. Nevertheless, evidence of a certain degree of clinical/biological heterogeneity has been disclosed by gene expression profile (GEP) and (immuno)genetic/immunohistochemistry studies. Aim. To use a GEP approach to identify MCL subsets with peculiar clinical/biological features in the context of MCL patients treated homogeneously with an autologous transplantation-based program. Methods. The study was based on a cohort of 42 MCL cases enrolled in the Fondazione Italiana Linfomi (FIL)-MCL-0208 randomized Italian clinical trial. Purified clonal CD19+ MCL cells were obtained by high-speed cell sorting of peripheral blood MCL samples. GEP experiments were performed in 30 cases, with Agilent platform. Bioinformatics analyses were performed by Gene Springs and Gene Set Enrichment Analysis (GSEA) software. Gene signature validations were performed by quantitative real time PCR (QRT-PCR). Results. i)Unsupervised and supervised analyses. Unsupervised analysis by principal component analysis (PCA) was able to divide the cohort in two main subgroups named PCA1 (12 cases) and PCA2 (18 cases). Supervised analysis by segregating cases according to the PCA1 and PCA2 classification defined a gene expression signature of 710 gene (234 up-regulated) that highlighted a constitutive overexpression of genes of the BCR signaling pathway. Consistently,GSEA showed a significant enrichment of genes belonging to 3 gene sets related to BCR signaling. ii) Identification of a "PCA2-type" gene signature. By merging the list of differentially expressed genes according to supervised analysis of GEP data and the gene list related to BCR signaling according to GSEA, a group of 9 genes, all overexpressed in PCA2 cases, i.e. AKT3, BLNK, BTK, CD79B, PIK3CD, SYK, BCL2, CD72, FCGR2B, was obtained. Among these genes, a subgroup of 6 genes, i.e. AKT3, BLNK, BTK, CD79B, PIK3CD, SYK, was selected for the direct involvement in the BCR pathway, and utilized for further validations. iii) Generation of a 6-gene prediction model. The selected 6 genes were then utilized to generate a prediction model by using 20 cases as training sub-cohort and the remaining 10 cases as validation cohort. By this approach, 9/10 cases of the validation cohort were correctly assigned according to the PCA2/PCA1 classification. The model was re-tested by QRT-PCR in 24 cases used in the GEP (16 for training and 8 for validation), and again, 7/8 cases of the validation sub-cohort were correctly classified. QRT-PCR was then utilized to classify further 12 cases (7 cases defined as PCA2) not employed for GEP analysis. Overall, in the 42 cases, 23 cases were considered as PCA2 with the GEP/QRT-PCR approach. iv) Clinical/biological correlations. No association was found between the 6-gene signature and IGHV status (22/30 unmutated IGHV cases) or between the signature and the overexpression of SOX11 (17/30 cases over the median value). In addition, no association was found with the presence of the main recurrent mutations of the ATM, BIRC3, CCND1, KMTD2, NOTCH1, TP53, TRAF2, WHSC1 genes. Finally, an "ad-interim" analysis of progression free survivals (PFS) (Cortelazzo et al EHA, 2015) suggested a trend for a shorter PFS (2-years PFS 45% vs 72%, p=0.08) for cases classified as PCA2 by the GEP/QRT-PCR approach. v) 6-gene signature and sensitivity to the BCR inhibitor ibrutinib. The finding that PCA2 cases overexpressed BCR-related genes and had a more aggressive clinical course prompted us to investigate the 6-gene signature in the context of ibrutinib sensitive/resistant MCL cell lines. To do this, the proliferation rate of the MCL cell lines REC1, JEKO1, UPN1, GRANTA, JVM2, Z138 was investigated either in presence or in absence of ibrutinib 10 nanoM for 7 days. REC1, JEKO1 were selected as responsive by showing ≥80% inhibition upon ibrutinib. Of note, responsive cell lines showed higher expression levels of the 6-gene signature then the resistant counterpart, as evaluated by QRT-PCR. Conclusions. A novel 6-gene expression signature related to the BCR pathway has been found to characterize MCL cells with peculiar clinical/biological features and sensitivity to BCR inhibitors. Disclosures Luminari: Roche: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees.

Background. The prognostic role of cell of origin profile (COO) assessed by immunohistochemistry (IHC) is controversial in Rituximab era. FIL conducted a phase III randomized trial aimed at investigating the benefit of intensification with high dose therapy plus autotransplant compared to R-dose-dense therapy as first line in young DLBCL at poor risk (aa-IPI 2-3). Clinical results were reported (Vitolo, ASH 2012). The aim of BIO-DLCL04 was to correlate the biological markers with PFS. Patients and Methods. From 2005 to 2010, 412 untreated DLBCL at aa-IPI 2-3 were enrolled. Central histology revision was mandatory and 13 patients were excluded due to different histologies. Biological markers were analyzed on DLBCL NAS; COO analysis was performed by IHC and cases were classified in germinal center (GC) and non-GC according to Hans' algorithm; COO determined by gene expression profile using the NanoString® nCounter® Analysis System based on 20-gene assay (Lymph2Cx) using formalin fixed paraffin embedded tissue is ongoing; BCL2, BCL6 and MYC anomalies were tested by IHC; final analysis by fluorescent in situ hybridization (FISH) is ongoing. Cases were deemed positive if at least 30% of lymphoma cells were stained with each antibody (with the exception of at least 40% for MYC). Results. At the time of this analysis, 223 DLBCL NAS were analyzed: 131 non-GC and 92 GC; BCL2, BCL6 and MYC anomalies were tested in 196, 74 and 107 cases respectively. Clinical characteristics for non-GC vs GC were: median age 51 years for both, male 49% vs 45%, aa-IPI 3 15% vs 25%, bone marrow involvement (BM) 16% vs 24%. R-HDC was performed in 45% of non-GC patients and in 49% of GC. Complete response was recorded in 105 (80%) non-GC patients and in 62 (67%) GC. At a median follow-up of 49 months, the 3-year PFS for non-GC vs GC was 75% (95% CI: 67-82) vs 57% (95% CI: 46-67) with crude hazard ratio, HR 0.55 (0.35-0.87), p.01 and adjusted (for age, gender, aa-IPI, BM) aHR 0.56 (0.35-0.88), p.013. No significant differences by treatment were reported. Overexpression of MYC by IHC had a relevant prognostic impact, with aHR 1.84 (0.99-3.44), p.054. By IHC, 3-years PFS for double negative vs single BCL2 or MYC overexpression vs double positive, was 85% vs 68% vs 51% respectively, with an aHR for double expressors compared to double negative of 3.91 (1.13-13.53), p.031. At the time of the present report, FISH analysis was conducted in 88 cases: 43 were triple negative, 37 single hit and 8 double/triple hit. By FISH, 3-years PFS for triple negative vs single hit vs double/triple hit was 74% vs 84% vs 25% respectively, with an aHR for double/triple hit compared to triple negative of 5.73 (2.05 to 16.02), p.001. Conclusions. In conclusion, with the limit of the analysis performed by IHC based on Hans' algorithm, BIO-DLCL04 showed an unexpected better outcome for non-GC compared to GC, irrespective of treatment arm. The ongoing analysis conducted by Nanostring will be more informative. The overexpression of MYC was an unfavourable risk factor, mainly if associated with BCL2 overexpression, irrespective of type of treatment. Moreover, double/triple hit patients represent a subgroup with extremely poor prognosis. High dose therapy plus autotransplant was not able to reverse the inferior outcome of neither double expressors nor double hit patients and new strategies are deemed for these poor prognosis patients. Disclosures No relevant conflicts of interest to declare.