Abstract: Abstract 2808 Poster Board II-784 Background and aims: Characterization of the IgH receptor provides useful insights to understand the pathogenesis and natural history of lymphoid tumors. For example the recognition of stereotyped clusters of immunoglobulin receptors has been a major step forward to understand the pathogenesis of chronic lymphocytic leukemia (CLL). IgH rearrangements have been less extensively investigated in MM, mostly because of lack of large databases of IgH sequences. At our Institution a large number of MM patients has undergone IgH sequencing for minimal residual disease (MRD) evaluation. This database has been merged with MM IgH sequences available in the literature, resulting in 308 MM sequences which have been employed to comprehensively investigate the characteristics of the IgH rearrangement in this tumor. Patients and methods: 131 IgH genes from MM patients were amplified and direct sequenced at our Institution (mostly for MRD detection purposes) from specific cDNA obtained at diagnosis, as already described (Voena et al, Leukemia 1997). 177 MM IgH sequences were derived from published databases (NCBI and EMBL). To further characterize the IgH repertoire, we have then compared the MM complementarity-determining region 3 (HCDR3) amino acid (AA) sequences to a panel of productive, non redundant 27413 HCDR3 AA sequences retrieved from public databases (EMBL, NCBI, IMGT/LIGM-DB: 25655 sequences) and from our unpublished laboratory database (1758 sequences), including sequences from malignant B-cell clones (3197 CLL, 1217 lymphomas) and from non malignant repertoire (2685 autoreactive, 4408 immunederegulation/immunodeficiency, 15429 normal and 477 phage display libraries). All the sequences have been analyzed using the IMGT database and tools (Lefranc et al., Nucleic Acid Res. 2005; http://imgt.cines.fr/) to identify IGHV, IGHD and IGHJ gene usage, to assess the somatic hypermutation (SHM) rate and to identify HCDR3 AA sequences. HCDR3 AA sequences were aligned together, in search of subsets of stereotyped receptors, using the ClustalX 2.0 software (http://www.clustal.org/). To define subsets of stereotyped IgH receptors, we followed the criteria proposed by Messmer et al. (J Exp Med. 2004) and Stamatopoulos et al. (Blood, 2007). Results: No significant differences were noted between our Institutional and published MM databases. Overall IGHV usage in MM appeared in keeping with the normal B cell repertoire with predominance of IGHV3 family (53.9%) followed by IGHV4 (slightly under-represented in MM, 17.2% vs 23.2%, p=0.02) and IGHV1 (12%); besides an over-representation of IGHV2 (7.8% vs 2.3%, p 〈 0.001) was noticed. A modest but significant (p 〈 0.05) over-representation of the IGHV3-9 (5.2% vs 2.6%), IGHV3-21 (4.5% vs 2%), IGHV5-51 (4.5% vs 2.2%) genes and under-representation of the IGHV3-23 (8.1% vs 12.2%) and IGHV4-34 (1% vs 6.5%, p 〈 0.001) were observed. IGHD and IGHJ followed a distribution similar to that of normal IgH repertoire. The median SHM rate was 7.5% (range 0-28%): interestingly we found one single patient with 100% identity to the germline sequence and only three patients with 〉 98% identity. The median length of the HCDR3 was 15 AA (range 7-29), again in line with normal IgH repertoire. Intra MM search for HCDR3 similarity showed no association which met minimal requirements to define stereotyped receptors. The comparison of MM sequences with non MM database showed that 98% of MM sequences are unrelated to known CLL subsets. Among the remaining, 3 MM sequences could be assigned to previously identified CLL subsets (namely n. 25, n. 37 and n. 71 according to Murray et al., Blood 2008) whereas 2 MM formed 2 novel provisional subsets with CLL. When HCDR3 MM were compared to the database of non MM/CLL HCDR3, similarities were found with clones from normal B cells, while similarities with autoreactive clones and other B cell malignancies were sporadic. Conclusions: The analysis of the largest database of MM IgH sequences so far reported indicate the following: 1) Family usage in the MM IgH repertoire follows a nearly physiological distribution apart for modest skewing of a number of IGHV genes; 2) MM specific HCDR3 clusters do not occur to a frequency detectable with currently available databases; 3) The vast majority of MM sequences are not related to known CLL clusters; 4) MM IgH sequences share more similarities with normal IgH sequences compared to those derived from pathological B lymphoid cells. Thus to state of current knowledge there is little evidence in favor of an antigen driven pathogenesis for this neoplasm. Disclosures: No relevant conflicts of interest to declare.

Abstract: 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 ( 〈 65 years) enrolled into the MCL0208 trial. Clinical results of the first interim analysis (without random unblinding) have been already reported and are the basis of the present analysis: median follow-up of alive patients was 26 months, and at 2-years, 79% of patients were progression free and 91% alive (Cortelazzo et al EHA 2015). DNA profiling with the Illumina HumanOmni2.5 arrays was performed on 174 DNA samples derived from baseline bone marrow CD19+ purified tumor cells. Genomic profiles were segmented with the Fast First-derivative Segmentation Algorithm (Rinaldi et al, BJH 2013; Kwee et al, bioRxiv 2016). Recurrent CNVs were defined applying both the minimal common regions and the GISTIC algorithms (Lenz et al, PNAS 2008; Mermel et al, Genome Biol 2011). CNVs were integrated with somatic mutational data obtained for 8 genes recurrently affected in MCL (ATM, BIRC3, CCND1, KMT2D, TP53, TRAF2, WHSC1, NOTCH1) (Rossi et al, ASH 2015). Progression free survival (PFS) was the primary endpoint of the analysis. 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 ( 〈 1%), deleted in 1/147 ( 〈 1%), and mutated in 16/147 (11%). 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.

Abstract: Abstract 746 Background The clinical benefit of high dose chemotherapy programs in patients with diffuse large B cell lymphomas (DLBCL) with unfavorable presentation (IPI 〉 2) is still matter of debate and several prospective randomized clinical trials have been conducted to address this point. Patients and study design In year 2005 the cooperative study group GITIL launched a multicenter phase III trial (R-HDS 0305, Clinical Trials.gov.number NCT00355199) in DLBCL patients without CNS involvement and the following inclusion criteria: age between 18–60 years, stage 〉 II B-bulk with ECOG-PS=0-3 and age adjusted IPI (aaIPI) 2–3 or age 61–65 years with ECOG-PS = 0–2 and IPI 〉 3. The control group received 8 courses of the conventional R-CHOP-14 chemotherapy program, followed by IFRT, in patients who achieved at least a partial response (PR) after 4 cycles. Cases refractory to R-CHOP-14 could be rescued by R-HDS. The experimental arm (R-HDS) included: 3 courses of doxorubicin-containing chemotherapy (APO), followed by high-dose cyclophosphamide (CTX) 7 g/sqm, Ara-C (2g/sqm every 12 hours for 6 days), etoposide 2 g/sqm plus cisplatin 100 mg/sqm. After R-HDS chemotherapy, a mitoxantrone-melphalan (60 and 180 mg/sqm, respectively) or BEAM conditioning regimen with autologous stem cell transplantation (ASCT) + IFRT, as above. Rituximab (375 mg/sqm) was given for a total of 6 doses, twice after CTX and Ara-C based cycles, as in vivo purging before CD 34+ cells harvest, and twice after ASCT (Tarella C. et al Leukemia 21:1802–1811, 2007). The primary end-point of the study was to test an increase of 2-year Event Free Survival (EFS) from 50% in the R-CHOP arm to 65% in the intensified R-HDS arm. Secondary end-points were Disease Free Survival (DFS), Overall Survival (OS) and toxicity. Results From June 2005 to June 2011, 248 patients were enrolled in the study (R-CHOP-14=127; R-HDS=121) and 241 were evaluable as to completeness of information. The median age was 51 years (range, 18–65), 32 subjects (13.3%) had 〉 60 years and the M/F ratio was 1.39. Clinical features were as follows: advanced Ann Arbor clinical stage (93%), BM infiltration (22%), bulky disease (69%), elevated LDH (87%), elevated beta 2-microglobulin (60%), poor ECOG-PS (61%), B-symptoms (57%), ≥2 extranodal sites (71%), IPI 2 (51%) and IPI 〉 3 (49%). The two arms were well balanced for all these features. No significant difference could be detected in the response rates of patients treated with R-CHOP and R-HDS that in detail, were the following: complete response (CR, 76% vs. 76%), partial response (PR, 4.7% vs. 7.9%), progressive disease (PD, 15% vs. 8.8%), stable disease (SD, 1.6% vs. 0.9%), treatment discontinuation for any reason (0 vs. 1.8%), early death (ED, 2.4% vs. 4.4%). On the contrary, the relapse rate was higher in the R-CHOP vs. the R-HDS arm (14% vs. 4.6%, p= 0.025). After a median follow-up of 27.7 months (range 0.3 – 52.5) the 2-year DFS of patients treated with R-CHOP or R-HDS is 83% vs. 93% (p=0.07) while the EFS is 68% vs. 73% (p= 0.345) (Figure 1 and 2). Similarly, with the current follow up, no significant difference could be detected in OS (77% vs. 80%, p= 0.398). The OS was better for patients with IPI 2 in comparison to those with IPI 〉 3 (84% vs. 73%; p= 0.04), but without any significant difference according to treatment arm. Although the rate of death in remission (2% in both arms) was similar, the overall toxicity of the R-HDS arm was higher in terms of hematologic toxicity (CTC G 〉 2) (p 〈 0.001) and infectious complications (p 〈 0.001). So far, no secondary malignancies have been observed. Conclusion In DLBCL patients with unfavorable presentation a conventional R-CHOP and a more intensive R-HDS chemotherapy achieved the same excellent rate of response. Despite a trend for a better DFS observed in patients treated with R-HDS, the EFS (primary endpoint of the study) and the OS are not different. A longer follow-up is needed in order to definitively rule out the role of intensified R-HDS program as first line treatment for poor-prognosis DLBCL patients. Disclosures: Tarella: Hoffmann-La Roche: Consultancy, Honoraria. Gianni:Hoffmann-La Roche: Consultancy, Honoraria. Pizzolo:Hoffmann-La Roche: Consultancy, Honoraria. Rambaldi:Hoffmann-La Roche: Consultancy, Honoraria.

Abstract: 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.

Abstract: Abstract 1784 Introduction. The outcome of MCL is unfavourable, with continuous relapses. The MIPI, a clinical score, defined performance status, age, LDH and leucocyte counts as predictors of MCL outcome. Ki-67 as cell proliferation index was evaluated in biological-MIPI (MIPI-b). Aim of the study was to tested MIPI on a retrospective group of MCL patients treated with Rituximab-chemotherapy with or without High Dose Chemotherapy and autologous stem cell transplantation (R-HDC); secondary endpoints were: to evaluate the feasibility of MIPI-b on a retrospective population and to quantify the predictive discrimination of IPI, MIPI, MIPI-b on the outcome of MCL in the Rituximab era. Methods. Between 1999 and 2009, 206 MCL 〉 18 years at diagnosis consecutively treated in seven Italian institutions were included into the study. Histology was centrally reviewed and, if possible, Ki-67 evaluation was performed. Overall survival (OS) and failure-free survival (FFS) curves were estimated both overall and stratified by MIPI, MIPI-b and IPI score. Differences between curves were tested using the 2-tailed log-rank test. In order to quantify the predictive discrimination of MIPI, MIPI-b and IPI scores, a Cox's model analysis and univariate logistic models (with death and failure event as binary outcomes) were fitted and the area under the receiver operating characteristic (ROC) curves (c-index) was estimated in a subgroup of 120 patients that fulfilled MIPI, MIPI-b and IPI scores. Results. Clinical characteristics were: median age 61 (34-85) years, 78% stage IV, 73% with bone marrow involvement, 16% with blastoid variant; median leucocyte counts at diagnosis was 7.53×103 (2.38-175). First-line treatments were: R-HDC in 51%, Rituximab-Fludarabine based chemotherapy in 12%, Rituximab-CHOP in 32% and other Rituximab containing regimens in 5%. Ki-67 evaluation was performed in 135 patients; median Ki-67 value was 30%. Patients at high-risk (HR) were 29% according to MIPI, 18% according to MIPI-b and 33% to IPI. With a median follow-up of 48 months, 4-year OS was 72% (95% CI:65-78) and 4-year FFS was 49% (95%CI: 41–56). Four-year OS according to MIPI by risk groups was: LR 94% (95%CI: 85–97), IR 66% (95%CI: 47–80), HR 41% (95%CI: 26–55) and according to IPI: LR 87% (95%CI: 73–94), IR 88% (95%CI: 74–95), HR 41% (95%CI: 26–55) (Figure 1). In the subgroup of 120 patients that fulfilled MIPI, MIPI-b and IP scores an univariate logistic model and a Cox's model analysis were fitted. The c-index and Cox-index for death event were 76% and 75% for MIPI, 69% and 69% for MIPIb, 76% and 71% for IPI respectively; the c-index and Cox-index for failure event were 61% and 68% for MIPI, 59% and 64% for MIPIb, 68% and 66% for IPI respectively. A sub-analysis was conducted to validate the role of MIPI in R-HDC group; an univariate logistic model and a Cox's model analysis were fitted and the c-index and Cox-index for death event and for failure event were calculated (Table 1). Conclusions. MIPI score was confirmed as a good predictor of death event in MCL retrospective patients treated with Rituximab-chemotherapy regimens. MIPI score should be a good predictor of death event also in patients treated with R-HDC. The impact of MIPI-b score should be tested in prospective trials, with central histology review. New therapeutic strategies are warranted to improve the outcome of MCL namely in MIPI-HR group. Disclosures: No relevant conflicts of interest to declare.

Abstract: The benefit of high-dose chemotherapy with autologous stem-cell transplantation (ASCT) as first-line treatment in patients with diffuse large B-cell lymphomas is still a matter of debate. To address this point, we designed a randomized phase III trial to compare rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP)-14 (eight cycles) with rituximab plus high-dose sequential chemotherapy (R-HDS) with ASCT. Patients and Methods From June 2005 to June 2011, 246 high-risk patients with a high-intermediate (56%) or high (44%) International Prognostic Index score were randomly assigned to the R-CHOP or R-HDS arm, and 235 were analyzed by intent to treat. The primary efficacy end point of the study was 3-year event-free survival, and results were analyzed on an intent-to-treat basis. Results Clinical response (complete response, 78% v 76%; partial response, 5% v 9%) and failures (no response, 15% v 11%; and early treatment-related mortality, 2% v 3%) were similar after R-CHOP versus R-HDS, respectively. After a median follow-up of 5 years, the 3-year event-free survival was 62% versus 65% ( P = .83). At 3 years, compared with the R-CHOP arm, the R-HDS arm had better disease-free survival (79% v 91%, respectively; P = .034), but this subsequently vanished because of late-occurring treatment-related deaths. No difference was detected in terms of progression-free survival (65% v 75%, respectively; P = .12), or overall survival (74% v 77%, respectively; P = .64). Significantly higher hematologic toxicity ( P 〈 .001) and more infectious complications ( P 〈 .001) were observed in the R-HDS arm. Conclusion In this study, front-line intensive R-HDS chemotherapy with ASCT did not improve the outcome of high-risk patients with diffuse large B-cell lymphomas.

Abstract: Introduction. The application of Pediatric-Type Therapy (PTT) programs to adults with ALL can improve outcome significantly despite higher age-related toxicity. Recent series reported survival rates ≥ 50%, but only few combined PTT with Minimal Residual Disease (MRD) study for risk-oriented Hematopoietic Cell Transplantation (HCT) and/or explored the value of specific PTT element such as higher dose, lineage-targeted MTX up to 5 g/m2. Methods. To improve over prior data, NILG protocol 10/07 (Clinical.Trials.gov NCT-00795756) for unselected adult patients aged 18-65 years combined PTT together with MRD study for risk/MRD-based HCT. The 8-course program consisted of a 5-drug complete remission (CR) induction (cycle no. 1; imatinib added if Ph+) followed by 3 modified BFM blocks (no. 2, 4 and 6), 3 lineage-targeted MTX blocks (no. 3, 5 and 7; MTX 5 g/m2 for T-ALL and 2.5 g/m2 for B-ALL [1.5 g/m2 if age 〉 55 years or Ph+]; no. 3 and 7 with high-dose Ara-C 2 g/m2 x4, no. 5 with L-Asp 10,000 IU/m2 x2) and reinduction (no. 8). CNS prophylaxis was with triple intrathecals or liposomal cytarabine (Haematologica 2015;100:786). MRD was studied molecularly with sensitive probe(s) (sensitivity 10-4 or greater) on marrow samples obtained at end of induction (week 4, w4) and after cycles 3 (w10), 5 (w16), 7 (w22) i.e. after 1st, 2nd and 3rd lineage-targeted MTX block. Patients were risk-stratified at diagnosis and after MRD analysis for the purpose of allocation to HCT or conventional maintenance. The HCT allocation cohort consisted of predefined very high-risk patients (vHR: WBC 〉 100, highly adverse cytogenetics, pre-T/mature T-ALL) regardless of MRD, of HR patients without MRD study (HR: late CR; B-ALL with WBC 〉 30 or pro-B phenotype), and of HR or standard-risk (SR) patients with MRD ≥ 10-4 at w10/16 or positive at w22. Conversely, the maintenance allocation cohort consisted of SR and HR patients with MRD 〈 10-4 at w10/16 and negative at w22 and of SR patients without MRD study. A family related/unrelated donor search was activated at diagnosis in order to proceed to HCT soon after cycle no. 3 when needed. Results. 205 patients were enrolled, with a median age of 41 years (range 17-67 years, 11% 〉 60 years). 55% were male, 42 had Ph+ ALL, 119 Ph- B-ALL and 44 T-ALL. Of 163 patients with Ph- ALL, 45% were SR, 13% HR and 42% vHR. CR rate was 98% in Ph+ ALL and T-ALL, and 83% in Ph- B-ALL (88% vs 58% in patients ≤ vs 〉 60 years, P .0013). The MRD study was successful in 109/142 CR patients with Ph- ALL (77%), contributing to the final risk classification in 63 patients, of whom 41 were MRD responsive (65%) and 22 MRD resistant (35%). Altogether, 55 CR patients constituted the maintenance allocation group (39%) and 87 the HCT allocation group (61%), which included mainly vHR patients (n=61, 43%) selected for HCT independently of MRD study results. According to intention-to-treat, median OS is not reached (53% at 5 years, figure) and median DFS is 4.8 years (48% at 5 years). In Ph- ALL, 5-year OS/DFS are 74%/61% in T-ALL (medians not reached) and 48% each in B-ALL (medians 3.9 and 4.7 years). Median OS is not reached in both HCT and maintenance allocation groups (58% and 73% at 5 years, respectively, P .078), with a median DFS of 4.7 years (48% at 5 years) versus not reached (59% at 5 years) (P .19). Treatment adherence was good with some exceptions in maintenance allocation group (6 HCT, 11%) and a transplant realization of 68% (53 allogeneic; 6 autologous) in HCT allocation group. With HCT, 5-year incidence of nonrelapse mortality was 17%. The MRD analysis proved that DFS of patients achieving an MRD response 〈 10-4 at w4 (n=46/90, 51%) or w10 (n=76/107, 71%) was significantly improved compared to those with MRD ≥ 10-4, with median not reached and 5-year rate 67% versus 4.5 years and 41% (w4 MRD; P .041), and 7.2 years and 64% versus 1 year and 23% (w10 MRD; P .0001). Conclusion. The current PTT and MRD-based risk-oriented strategy was applicable to adults with ALL in a wide age range, with some limitations in patients 〉 60 years. 5-year OS and DFS of 55% and 52% respectively in Ph- patients aged up to 65 years represent an improvement over prior NILG study (5-year OS and DFS of 36% and 35% respectively). MRD was essential in orientating the HCT choice in SR and HR patients and retained a major prognostic role in all patients. Optimizing the early MRD response with new immunotherapeutics and clarifying the role of HCT in MRD responsive vHR patients are some relevant topics of future research. Figure Figure. Disclosures Ciceri: MolMed SpA: Consultancy. Vitolo:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria; Gilead: Honoraria; Celgene: Honoraria; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Gallamini:Millenium Takeda: Membership on an entity's Board of Directors or advisory committees.

Abstract: Abstract 2951 Background: The identification of stereotyped immunoglobulin (IG) receptors has improved our knowledge on the pathogenesis of several B-cell malignancies, suggesting the role of antigen-driven stimulation in chronic lymphocitic leukemia (CLL), marginal-zone lymphoma (MZL) and mantle-cell lymphoma (MCL). Multiple myeloma (MM) is a terminally-differentiated neoplasm no longer expressing surface IG; however some reports suggest the existence of early B-lymphocyte precursors which could be susceptible to antigen-driven stimulation. IG heavy chain (IGH) repertoire has not been extensively investigated in MM, with the largest available reports containing less than 80 complete sequences. Aims: To address this issue we created a database of MM IGH sequences including our institutional records (mostly derived from minimal residual disease studies) and sequences available from the literature. We planned a two-step analysis: a) first we characterized the MM repertoire and performed intra-MM clustering analysis; b) then we compared our MM series to a large public database of IGH sequences from neoplastic and non-neoplastic B-cells in search of similarities between MM sequences and other normal or neoplastic IGH repertoires. Patients and methods: 131 MM IGH genes were amplified and sequenced at our Institutions and belonged to Italian patients, while 214 MM IGH sequences from non-Italian patients were derived from published databases (NCBI-EMBL-IMGT/LIGM-DB) for a total of 345 fully interpretable MM sequences (out of 396). 28590 IGH sequences from other malignant and non-malignant B-cells were retrieved from the same public databases, including approximately 4500 CLL/Non-Hodgkin lymphoma (NHL) sequences and comprising 500 sequences from Italian patients. All sequences were analyzed using the IMGT database and tools (Lefranc et al., Nucleic Acid Res. 2005; http://imgt.cines.fr/) to identify IGHV-D-J gene usage, to assess the somatic hypermutation (SHM) rate and to identify HCDR3. HCDR3 aminoacidic sequences were aligned together using the ClustalX 2.0 software (Larkin et al., Bioinformatics, 2007; http://www.clustal.org/). Subsets of stereotyped IGH receptors were defined according to Stamatopoulos et al. (Blood, 2007). Result: IGHV analysis in MM was almost in keeping with the normal B-cell repertoire, showing a less remarkably biased IGH usage compared to CLL, MCL and MZL (with seven genes accounting for 40% of cases, compared to respectively five, three and two genes). However, a modest but significant over-representation of IGHV1-69, 2–5, 2–70, 3–21, 3–30-3, 3–43, 5–51 and 6-1 genes and under-representation of the IGHV1-18, 1–8, 3–30, 3–53 and 4–34 was noticed. The rate of somatic hypermutation in MM followed a Gaussian distribution with a median value of 7.8%. Intra-MM search for HCDR3 similarities never met minimal requirements for stereotyped receptors. When MM sequences were compared to non-MM database, only a minority of MM sequences (2.6%, n=9) clustered with sequences from lymphoid tumors and normal B-cells (figure 1A). In particular two non-Italian MM sequences clustered with previously characterized, uncommon CLL subsets (n.37 and n.71 according to Murray et al., Blood 2008). Moreover, novel provisional clusters were observed including three MM-CLL subsets, one MM-NHL subset, and three MM-normal B-cell subsets. While the MM-normal B-cell clusters involved non-Italian patients, we unexpectedly noticed that the four MM-CLL/MM-NHL clusters were composed exclusively of Italian patients, as shown in figure 1B, although Italian subjects represented less than 12% of the entire CLL-NHL database. Conclusion: The analysis of the largest currently available database of MM IGH sequences indicates the following: 1) MM IGH repertoire is closer to physiological distribution than that of CLL, MCL and MZL; 2) MM specific clusters do not occur to a frequency detectable with currently available databases; 3) 98% of MM sequences are not related to other “highly-clustered” lymphoproliferative disorders; 4) Uncommon clustering phenomena may follow a geographical rather than a disease-related pattern. Disclosures: No relevant conflicts of interest to declare.