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We studied pre-transplant minimal residual disease (MRD) in 224 patients (median age 44 years; range 17-65) with acute myeloid leukemia (AML) undergoing allogeneic stem cell transplant (HSCT) in complete remission. MRD was evaluated on marrow samples using multicolor flow cytometry (MFC) and assessment of WT1 gene expression. Both methods showed a strong prognostic value and their combination allowed the identification of 3 groups of patients with different risk of relapse. In multivariate analysis, combined MRD was the only predictor of cumulative incidence of relapse, regardless of donor type, conditioning regimen, first or second CR at HSCT, HSCT year and ELN risk group. Multivariate regression model showed that only negative combined MRD status (p

Metabolic reprogramming is emerging as a cancer vulnerability that could be therapeutically exploitable using different approaches, including amino acid depletion for those tumors that rely on exogenous amino acids for their maintenance. ʟ-Asparaginase (ASNase) has contributed to a significant improvement in acute lymphoblastic leukemia outcomes; however, toxicity and resistance limit its clinical use in other tumors. Here, we report that, in multiple myeloma (MM) cells, the DNA methylation status is significantly associated with reduced expression of ASNase-related gene signatures, thus suggesting ASNase sensitivity for this tumor. Therefore, we tested the effects of ASNase purified from Erwinia chrysanthemi (Erw-ASNase), combined with the next-generation proteasome inhibitor (PI) carfilzomib. We observed an impressive synergistic effect on MM cells, whereas normal peripheral blood mononuclear cells were not affected. Importantly, this effect was associated with increased reactive oxygen species (ROS) generation, compounded mitochondrial damage, and Nrf2 upregulation, regardless of the c-Myc oncogenic-specific program. Furthermore, the cotreatment resulted in genomic instability and DNA repair mechanism impairment via increased mitochondrial oxidative stress, which further enhanced its antitumor activity. Interestingly, carfilzomib-resistant cells were found to be highly dependent on amino acid starvation, as reflected by their higher sensitivity to Erw-ASNase treatment compared with isogenic cells. Overall, by affecting several cellular programs, Erw-ASNase makes MM cells more vulnerable to carfilzomib, providing proof of concept for clinical use of this combination as a novel strategy to enhance PI sensitivity in MM patients.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a poor prognosis myeloid malignancy characterized by an atypical phenotype (CD123+, CD56+, and CD4+). We reported that BPDCN-like phenotype (CD123+ and either CD56+ or CD4+ or both) confers poor prognosis to acute myeloblastic leukemia (AML) patients with mutated NPM1. Here, we evaluated the incidence and the prognostic relevance of BPDCN-like phenotype in cytogenetically normal AML (CN-AML) patients. From 2006 to 2016, 83 young (age60 yrs), consecutive, CN-AML patients underwent intensive treatment. Fifteen patients (18%) showed a BPDCN-like phenotype with no difference between

Immune checkpoint inhibitors (CI) have demonstrated clinical activity in Hodgkin Lymphoma (HL) patients relapsing after autologous stem cell transplantation (ASCT), although only 20% complete response (CR) rate was observed. The efficacy of CI is strictly related to the host immune competence, which is impaired in heavily pre-treated HL patients. Here, we aimed to enhance the activity of early post-ASCT CI (nivolumab) administration with the infusion of autologous lymphocytes (ALI). Twelve patients with relapse/refractory (R/R) HL (median age 28.5 years; range 18-65), underwent lymphocyte apheresis after first line chemotherapy and then proceeded to salvage therapy. Subsequently, 9 patients with progressive disease at ASCT received early post-transplant CI supported with four ALI, whereas 3 responding patients received ALI alone, as a control cohort. No severe adverse events were recorded. HL-treated patients achieved negative PET scan CR and 8 are alive and disease-free after a median follow-up of 28 months. Four patients underwent subsequent allogeneic SCT. Phenotypic analysis of circulating cells showed a faster expansion of highly differentiated NK cells in ALI plus nivolumab-treated patients as compared to control patients. Our data show anti-tumor activity with good tolerability of ALI + CI for R/R HL and suggest that this setting may accelerate NK cell development/maturation and favor the expansion of the “adaptive” NK cell compartment in patients with HCMV seropositivity, in the absence of HCMV reactivation.

Background Erythropoiesis‐stimulating agents effectively improve the hemoglobin levels in a fraction of anemic patients with myelodysplastic syndromes (MDS). Higher doses (HD) of recombinant human erythropoietin (rhEPO) have been proposed to overcome suboptimal response rates observed in MDS patients treated with lower “standard doses” (SD) of rhEPO. However, a direct comparison between the different doses of rhEPO is lacking. Methods A cohort of 104 MDS patients treated with HD was retrospectively compared to 208 patients treated with SD in a propensity score‐matched analysis to evaluate hematological improvement‐erythroid (HI‐E) rate induced by the different doses of rhEPO. The impact of rhEPO doses on survival and progression to leukemia was also investigated. Results Overall HI‐E rate was 52.6%. No difference was observed between different rhEPO doses (P = .28) in matched cohorts; in a subgroup analysis, transfusion‐dependent patients and patients with higher IPSS‐R score obtained a higher HI‐E rate with HD, although without significant impact on overall survival (OS). Achievement of HI‐E resulted in superior OS. At univariate analysis, a higher HI‐E rate was observed in transfusion‐independent patients (P, When compared in a propensity‐score matched analysis, standard doses of rhEPO showed similar effects to those of higher doses in anemic MDS patients. Achievement of favorable response with hematologic improvement in this clinical scenario is possible by reducing drug doses and costs.

Cisplatin-containing salvage regimens followed by autologous hematopoietic stem cell (HSC) transplantation are the current standard of care for relapsed or refractory (R/R) lymphomas. We retrospectively analyzed efficacy and stem cell mobilizing activity of oxaliplatin, cytarabine, dexamethasone and rituximab (R-DHAOx) in 53 R/R diffuse large B cell lymphomas (DLBCL) treated in our center (median lines 2, range 2-5; median age 59, range 22-79). Hematological toxicity was manageable and no patients experienced renal impairment. After 2 courses the overall response rate was 60% (CR 49%, PR 11%). Median overall survival (OS) was 30.53 months (95% CI 11.5-49.55), 3-year OS 40.5%. Twenty-two eligible patients collected HSC and transplantation was performed in 21/22 patients (95%), after a median of 52 days from last cycle. Our results suggest that in DLBCL R-DHAOx has an excellent stem cell mobilizing capability, response rate comparable to cisplatin-containing regimens and good toxicity profile.

Identification of novel vulnerabilities in the context of therapeutic resistance is emerging as a key challenge for cancer treatment. Recent studies have detected pervasive aberrant splicing in cancer cells, supporting its targeting for novel therapeutic strategies. Here, we evaluated the expression of several spliceosome machinery components in multiple myeloma (MM) cells and the impact of splicing modulation on tumor cell growth and viability. A comprehensive gene expression analysis confirmed the reported deregulation of spliceosome machinery components in MM cells, compared to normal plasma cells from healthy donors, with its pharmacological and genetic modulation resulting in impaired growth and survival of MM cell lines and patient-derived malignant plasma cells. Consistent with this, transcriptomic analysis revealed deregulation of BCL2 family members, including decrease of anti-apoptotic long form of myeloid cell leukemia-1 (MCL1) expression, as crucial for “priming” MM cells for Venetoclax activity in vitro and in vivo, irrespective of t(11;14) status. Overall, our data provide a rationale for supporting the clinical use of splicing modulators as a strategy to reprogram apoptotic dependencies and make all MM patients more vulnerable to BCL2 inhibitors.

BACKGROUND Azacitidine (AZA) is the standard treatment for myelodysplastic syndromes (MDS); however, many patients prematurely stop therapy and have a dismal outcome. METHODS The authors analyzed outcomes after AZA treatment for 402 MDS patients consecutively enrolled in the Italian MDS Registry of the Fondazione Italiana Sindromi Mielodisplastiche, and they evaluated the North American MDS Consortium scoring system in a clinical practice setting. RESULTS At treatment discontinuation, 20.3% of the patients were still responding to AZA, 35.4% of the cases had primary resistance, and 44.3% developed adaptive resistance. Overall survival (OS) was better for patients who discontinued treatment while in response because of planned allogeneic hematopoietic stem cell transplantation (HSCT; median OS, not reached) in comparison with patients with primary resistance (median OS, 4 months) or adaptive resistance (median OS, 5 months) or patients responsive but noncompliant/intolerant to AZA (median OS, 4 months; P = .004). After AZA discontinuation, 309 patients (77%) received best supportive care (BSC), 60 (15%) received active treatments, and 33 (8%) received HSCT. HSCT was associated with a significant survival advantage, regardless of the response to AZA. The North American MDS Consortium scoring system was evaluable in 278 of the 402 cases: patients at high risk had worse OS than patients at low risk (3 and 7 months, respectively; P < .001). The score was predictive of survival both in patients receiving BSC (median OS, 2 months for high-risk patients vs 5 months for low-risk patients) and in patients being actively treated (median OS, 8 months for high-risk patients vs 16 months for low-risk patients; P < .001), including transplant patients. CONCLUSIONS Real-life data confirm that this prognostic scoring system for MDS patients failing a hypomethylating agent seems to be a useful tool for optimal prognostic stratification and for choosing a second-line treatment after AZA discontinuation.

Bone skeletal alterations are no longer considered a rare event in chronic lymphocytic leukemia (CLL), especially at more advanced stages of the disease. This study is aimed at elucidating the mechanisms underlying this phenomenon. Bone marrow stromal cells, induced to differentiate toward osteoblasts in osteogenic medium, appeared unable to complete their maturation upon co-culture with CLL cells, CLL-cell-derived conditioned media (CLL-cm) or CLL-sera (CLL-sr). Inhibition of osteoblast differentiation was documented by decreased levels of RUNX2 and osteocalcin mRNA expression, by increased osteopontin and DKK-1 mRNA levels, and by a marked reduction of mineralized matrix deposition. The addition of neutralizing TNFα, IL-11 or anti-IL-6R monoclonal antibodies to these cocultures resulted in restoration of bone mineralization, indicating the involvement of these cytokines. These findings were further supported by silencing TNFα, IL-11 and IL-6 in leukemic cells. We also demonstrated that the addition of CLL-cm to monocytes, previously stimulated with MCSF and RANKL, significantly amplified the formation of large, mature osteoclasts as well as their bone resorption activity. Moreover, enhanced osteoclastogenesis, induced by CLL-cm, was significantly reduced by treating cultures with the anti-TNFα monoclonal antibody infliximab. An analogous effect was observed with the use of the BTK inhibitor, ibrutinib. Interestingly, CLL cells co-cultured with mature osteoclasts were protected from apoptosis and upregulated Ki-67. These experimental results parallel the direct correlation between amounts of TNFα in CLL-sr and the degree of compact bone erosion that we previously described, further strengthening the indication of a reciprocal influence between leukemic cell expansion and bone structure derangement.

Background: The presence of peripheral blasts (PB) is a negative prognostic factor in patients (pts) with primary and secondary myelofibrosis (PMF/SMF) and PB ≥4% was associated with a particularly unfavorable prognosis (Masarova L et al, Cancer 2020). Ruxolitinib (RUX) is the JAK1/2 inhibitor most used for treatment of MF-related splenomegaly and symptoms. Its role has not been assessed in correlation with PB. Aims: To evaluate the impact of PB percentage on RUX efficacy and prognosis Methods: After IRB approval, the "RUX-MF" retrospective study collected 804 RUX-treated chronic-phase (CP, defined as PB Comparisons of quantitative variables between the 3 groups were carried out by Kruskal-Wallis and Dunn's tests while association between categorical variables was tested by the χ2 test. Variables significantly associated to RUX stop/leukemic transformation (LT)/overall survival (OS) in univariate analysis (Log-rank test) were considered for multivariable analyses, carried out using the Cox regression model, with evaluation of the model's performance in terms of goodness of fit. Results: Pts were categorized according to PB at RUX start: PB-0 (no PB; n. 487, 61.3%), PB-5 (PB 1-5%; n. 283, 35.8%), and PB-9 (PB 6-9%; n. 24, 2.9%). Pts characteristics at RUX start were: median age 68.1y (24-89); males 58.1%; PMF 52.5%; JAK2, CALR and MPL mutated: 80.5%, 13.1% and 2% (4.4% triple negative), high DIPSS: 7.6%; PLT25 x10 9/l: 10.8%/16.4%; spleen length ≥10 cm: 47.8%, TSS ≥20: 60.6%; ≥1/≥2 high-risk mutation (HMR): 69/18 out of 167 evaluable (41.3%/10.8%); fibrosis grade ≥2: 77.9%; starting/cumulative RUX dose ≥15 mg BID: 61.4%/52.6%. Higher PB count was associated to high DIPSS risk (PB-0: 1.9%, PB-5: 16.2%, PB-9: 21.7%, p At 3 and 6 mos, 26.9% and 30.4% of evaluable pts achieved a SR, while 59.7% and 68.1% were in SyR, respectively. At 3 mos, SR (PB-0: 31.8%, PB-5: 20.6%, PB-9: 10%, p=0.001) and SyR (PB-0: 62.9%, PB-5: 55.5%, PB-9: 36.8%, p=0.02) were less frequently achieved by PB-5 and PB-9 pts compared to PB-0 pts. This association remained significant for SR at 6 mos (PB-0: 35%, PB-5: 23.9%, PB-9: 14.3%, p=0.006) and for both SR (p=0.003) and SyR (p=0.01) at any time. After a median RUX exposure of 1.5 y (0.1-8.9), 491 (61.8%) pts stopped RUX, 110 (13.9%) had a LT and 365 (46%) died. In univariate analysis, at 2y PB-9 pts had higher rates of RUX stop (73.9% vs 40.8% and 34.3% in PB-5 and PB-0 pts, log-rank p In multivariable analysis, PB-9 pts confirmed their association with: 1) RUX stop (HR 3.74, 95%CI 1.51-3.70, p20 (HR 1.66, 95%CI 1.05-2.61, p=0.03), and HMR≥2 (HR 2.69, 95%CI 1.26-4.47, p=0.007); 2) LT (HR 3.71, 95%CI 1.71-8.04, p Conclusions: CP-MF pts with PB>5% have a worse response to RUX and a worse outcome. Personalized approaches beyond RUX monotherapy may be useful in this context. Further clinical trials evaluating combination strategies and new drugs are required. Figure 1 Figure 1. Disclosures Palandri: Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; AOP: Membership on an entity's Board of Directors or advisory committees; Sierra Oncology: Membership on an entity's Board of Directors or advisory committees; CTI: Consultancy. Abruzzese: Bristol Myers Squibb: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria. Iurlo: Bristol Myers Squibb: Speakers Bureau; Pfizer: Speakers Bureau; Novartis: Speakers Bureau; Incyte: Speakers Bureau. Bonifacio: Bristol Myers Squibb: Honoraria; Novartis: Honoraria; Pfizer: Honoraria; Amgen: Honoraria. Cuneo: AbbVie: Consultancy, Speakers Bureau; AstraZeneca: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Gilead: Consultancy, Speakers Bureau. Pane: AbbVie; Amgen; Novartis: Other: Travel, accommodation, expenses; Novartis Pharma SAS;: Research Funding; AbbVie; Amgen; Novartis, GSK , Incyte: Consultancy; AbbVie; Amgen; Novartis, GSK, Incyte: Speakers Bureau. Lemoli: Celgene: Other: Support for attending meetings and/or travel; Jazz, Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie, Daiichi Sankyo, Servier: Honoraria, Speakers Bureau. Cavo: Bristol-Myers Squib: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, 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, Other: TRAVEL, ACCOMMODATIONS, EXPENSES, Speakers Bureau; Adaptive Biotechnologies: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Accommodations, Speakers Bureau; GlaxoSmithKline: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Breccia: Novartis: Honoraria; Pfizer: Honoraria; Incyte: Honoraria; Bristol Myers Squibb/Celgene: Honoraria; Abbvie: Honoraria.

Genomic instability plays a pathological role in various malignancies, including acute myeloid leukemia (AML), and thus represents a potential therapeutic target. Recent studies demonstrate that SIRT6, a NAD + -dependent nuclear deacetylase, functions as genome-guardian by preserving DNA integrity in different tumor cells. Here, we demonstrate that also CD34 + blasts from AML patients show ongoing DNA damage and SIRT6 overexpression. Indeed, we identified a poor-prognostic subset of patients, with widespread instability, which relies on SIRT6 to compensate for DNA-replication stress. As a result, SIRT6 depletion compromises the ability of leukemia cells to repair DNA double-strand breaks that, in turn, increases their sensitivity to daunorubicin and Ara-C, both in vitro and in vivo In contrast, low SIRT6 levels observed in normal CD34 + hematopoietic progenitors explain their weaker sensitivity to genotoxic stress. Intriguingly, we have identified DNA-PKcs and CtIP deacetylation as crucial for SIRT6-mediated DNA repair. Together, our data suggest that inactivation of SIRT6 in leukemia cells leads to disruption of DNA-repair mechanisms, genomic instability and aggressive AML. This synthetic lethal approach, enhancing DNA damage while concomitantly blocking repair responses, provides the rationale for the clinical evaluation of SIRT6 modulators in the treatment of leukemia.

NPM1 and FLT3 mutational status assessment is recommended in acute myeloid leukemia (AML) at diagnosis by European Leukemia Net (ELN) risk stratification. The presence of NPM1 mutation (NPM1-mut) partially overcomes the negative prognostic impact of FLT3-ITD, which is also modulated by FLT3-ITD/wild-type allelic ratio. Targeted drugs are available for FLT3-mutated AML but no data are available so far on the efficacy of intensified front-line regimens in overcoming the negative prognostic role of FLT3-ITD mutation. We investigated the efficacy of an intensive fludarabine, high dose cytarabine (ARA-C) and Idarubicin (IDA) induction regimen (FLAI) as frontline treatment for fit, de novo AML patients according to NPM1 and FLT3-ITD mutational status. One-hundred and forty-nine consecutive AML patients, treated in 3 Hematology Italian centers from January 2008 to January 2018, were included in this analysis. Twenty nine patients had isolated FLT3-ITD, 59 concomitant FLT3-ITD and NPM1-mut and 61 isolated NPM1-mut. Median age was 51 yrs (range: 18-65). All patients received FLAI induction (fludarabine 30 mg/sqm and ARA-C 2g/sqm on days 1 to 5 plus IDA 10 mg/sqm on days 1-3-5). For patients achieving CR fludarabine was omitted on II induction and IDA dose was increased to 12 mg/sqm. Before ELN 2017 risk stratification was adopted, patients with isolated FLT3-ITD mutation were scheduled to receive allogeneic bone marrow transplantation (allo-BMT) in first CR regardless of allelic burden. For patients with AML with NPM1 mutation and concomitant FLT3-ITD indication to allo-BMT in 1st complete remission was mainly based on minimal residual disease (MRD) status. MRD was evaluated on marrow samples using multicolor flow-cytometry (MFC) or NPM1 expression levels. Negative MFC-MRD was defined by the presence of less than 25 clustered leukemic cells/105 total events (threshold of 0.025%, Minetto et. al, BJH 2019). NPM1-mut (NPM1-A, B and D) was measured using Muta Quant Kit Ipsogen from Qiagen. FLT3-ITD allelic burden was available in31/64 of FLT3-ITD patients. Overall, 60-days mortality was 4.7%. After first induction cycles, 129 patients achieved CR (86.6%). Thirty-five/129 (25.5%) CR patients underwent BMT in first CR. After a median follow up of 68 months, 3-year overall survival (OS) was 58.6% (median not reached). In univariate analysis OS duration was affected by NPM1, FLT3 mutational status and ELN risk score. However, NPM1-mutated patient was not negatively affected by the presence of FLT3-ITD, regardless of allelic burden. This observation was even more evident in patients younger than 55 yrs (3 yy OS 64% and 68% for NPM1-mutated with or w/o FLT3-ITD, respectively (p=n.s, Figure 1), regardless of FLT3-ITD allelic burden. ELN 2017 high risk patients displayed the worst prognosis (3-year OS 35.2%). Multivariate analysis showed that NPM1 mutation was the strongest predictor of survival. In order to assess the impact of allo-BMT in 1st CR we performed a Landmark Analysis including patients alive and in CR at day 90. Interestingly, performing allo-BMT in 1st CR did not impact OS in the whole cohort of patients and irrespectively of NPM1 and FLT3 mutational status. The only subgroup who benefit from allo-BMT in first CR was high risk ELN2017 (p Despite the potential bias due to the retrospective nature of the analysis, our data indicate that intensive fludarabine-high dose cytarabine-based induction exerts a strong anti-leukemic efficacy in younger AML patients carrying NPM1 mutation irrespectively of FLT3 mutational status. Our data potentially question the role of BMT in first CR in this setting. Figure Disclosures Bocchia: CELGENE: Honoraria; Incyte: Honoraria.

Tyrosine kinases have been implicated in promoting tumorigenesis of several human cancers. Exploiting these vulnerabilities has been shown to be an effective anti-tumor strategy as demonstrated for example by the Bruton's tyrosine kinase (BTK) inhibitor, ibrutinib, for treatment of various blood cancers. Here, we characterize a new multiple kinase inhibitor, ARQ531, and evaluate its mechanism of action in preclinical models of acute myeloid leukemia. Treatment with ARQ531, by producing global signaling pathway deregulation, resulted in impaired cell cycle progression and survival in a large panel of leukemia cell lines and patient-derived tumor cells, regardless of the specific genetic background and/or the presence of bone marrow stromal cells. RNA-seq analysis revealed that ARQ531 constrained tumor cell proliferation and survival through Bruton's tyrosine kinase and transcriptional program dysregulation, with proteasome-mediated MYB degradation and depletion of short-lived proteins that are crucial for tumor growth and survival, including ERK, MYC and MCL1. Finally, ARQ531 treatment was effective in a patient-derived leukemia mouse model with significant impairment of tumor progression and survival, at tolerated doses. These data justify the clinical development of ARQ531 as a promising targeted agent for the treatment of patients with acute myeloid leukemia.

Acute myeloid leukemia with biallelic mutation of CEBPA (CEBPA-dm AML) is a distinct good prognosis entity recognized by WHO 2016 classification. However, testing for CEBPA mutation is challenging, due to the intrinsic characteristics of the mutation itself. Indeed, molecular analysis cannot be performed with NGS technique and requires Sanger sequencing. The association of recurrent mutations or translocations with specific immunophenotypic patterns has been already reported in other AML subtypes. The aim of this study was the development of a specific cytofluorimetric score (CEBPA-dm score), in order to distinguish patients who are unlikely to harbor the mutation. To this end, the correlation of CEBPA-dm score with the presence of the mutation was analyzed in 50 consecutive AML patients with normal karyotype and without NPM1 mutation (that is mutually exclusive with CEBPA mutation). One point each was assigned for expression of HLA DR, CD7, CD13, CD15, CD33, CD34 and one point for lack of expression of CD14. OS was not influenced by sex, age and CEBPA-dm score. Multivariate OS analysis showed that CEBPA-dm (p 0.02) and FLT3-ITD (p 0.01) were the strongest independent predictors of OS. With a high negative predictive value (100%), CEBPA-dm score6 was able to identify patients who are unlikely to have the mutation. Therefore, the application of this simple score might optimize the use of expensive and time-consuming diagnostic and prognostic assessment in the baseline work up of AML patients.

Introduction. The association of Azacitidine (AZA) and Lenalidomide (LEN), either administered concurrently or sequentially, has proven effective in Myelodysplastic Syndromes (MDS), however the optimum dose and schedule remains unknown. The aim of this study was to evaluate the efficacy and safety of the combination vs the sequential use of AZA and LEN in higher-risk MDS pts. Primary endpoint: ORR, defined as the Rate of Complete Remission (CR), Partial Remission (PR), Marrow Complete Remission (mCR), and Hematological Improvement (HI), following the IWG criteria (Cheson, 2006). Moreover, the aim of this analysisis is to enucleate the clinical and biological features of pts who showed long-lasting (≥ 20 cycles) responses. Methods. This is a randomized, phase II, multicenter, open label study, including pts with MDS with IPSS risk High or Intermediate-2, without previous treatment with AZA or LEN. ARM 1 (combined treatment): AZA: 75 mg/m2/day (days 1-5) I.C. + LEN: 10 mg/day (days 1-21), orally, every 4 weeks. ARM 2 (sequential treatment): AZA: 75 mg/m2/day (days 1-5) I.C. + LEN: 10 mg/day (days 6-21), orally, every 4 weeks. The induction treatment was planned for 8 cycles. For responder pts the same treatment was continued until disease progression or unacceptable toxicity. Results. From March 2013, 44 pts (27 males), median age: 72 (48-83 yrs) were enrolled, from 13 hematologic Centers. 21 pts were randomly assigned to ARM 1, and 23 pts to ARM 2. Treatment was given for a median of 8.5 (1-68) cycles; in ARM 1: 9 (1-68) cycles; in ARM 2: 8 (1-63) cycles, respectively. Median follow-up: 15 (2-77) months. 10/44 pts (22.7%) did not complete at least 6 cycles of treatment for causes other than disease progression, and were not considered evaluable for response. Among the 34/44 pts (77.3%) evaluable for response, 26/34 pts (ORR: 76.5 %) showed a favourable response to treatment. Intention-to-treat (ITT) analysis: ORR: 59.1%. First response was observed after a median of 2 (1-8) cycles. The Best Response achieved was: CR: 8 pts (23.5%) (ITT: 18.1%), PR: 1 pt (2.9%) (ITT: 2.2%), mCR: 3 pts (8.8%) (ITT: 6.8%), HI: 8 pts (23.5%) (ITT: 18.1%), mCR+HI: 6 pts (17.6%) (ITT: 13.6%). Median duration of hematologic response: 10.5 months. 37 pts (84.1%) died , and 20 pts (45.4%) showed progression to AML. Grade >2 non haematological toxicity: 54.5%. Median OS: 15 months. OS was significantly longer in responder pts as compared to the other pts (28 vs 7 months, p2 non haematological toxicity (ARM 1: 66.7%; ARM 2: 43.5%), AML incidence (ARM 1: 33.3%; ARM 2: 56.5%; p=0.2150) and OS (ARM 1: 14 months; ARM 2: 16 months). However, among responder pts, sequential treatment showed a longer clinical benefit, as compared to combined treatment. Responder pts of ARM 2 showed a significantly longer median duration of response (18 vs 6 months, p=0.0481), a longer median duration of therapy (28 vs 10 months, p=0.0870; 20 vs 10 cycles, p=0.1181), more long-lasting (≥ 20 cycles) responses (34.8% vs 9.5%, p=0.1017) and a longer OS (35 vs 26 months, p=0.3868), as compared to responder pts of ARM 1. Overall, 10/44 long-responder pts (22.7%) received ≥ 20 cycles; 5/10 pts (50%) achieved CR. IPSS risk: Intermediate-2 (8 pts); High (2 pts); IPSS-R risk: Intermediate (2 pts); High (6 pts); Very High (2 pts); IPSS cytogenetic risk: Good (5 pts); Intermediate (3 pts); Poor (2 pts); IPSS-R cytogenetic risk: Good (5 pts); Intermediate (4 pts); Very Poor (1 pt); 4/6 patients with altered karyotype achieved cytogenetic remission; it is noteworthy that the only 3 pts of the entire series who showed no gene mutations at baseline are included in this subset of long-responders pts, while 5/10 pts showed at baseline ≥ 1 prognostically unfavorable gene mutations (none with TP53 mutations), with variable VAFs during treatment. Moreover all long-responder pts showed a common gene mutation on SOD2 gene, and mutations on PLCG2 gene. Conclusions. Our results confirm the efficacy of both AZA+LEN treatment regimens in higher-risk MDS pts, in terms of ORR and OS, although sequential treatment was associated with a longer clinical benefit among responder pts. A subset of pts (22,7 %) with less unfavorable cytogenetic and molecular characteristics showed a long-lasting response to treatment. Disclosures Finelli: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees. Crugnola:BMS: Honoraria; Janssen: Honoraria; Celgene: Honoraria; Novartis: Honoraria. Rigolin:Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Cavo:Jannsen, BMS, Celgene, Sanofi, GlaxoSmithKline, Takeda, Amgen, Oncopeptides, AbbVie, Karyopharm, Adaptive: Consultancy, Honoraria.

Specific myeloid-related and inositide-specific gene mutations can be linked to myelodysplastic syndromes (MDS) pathogenesis and therapy. Here, 44 higher-risk MDS patients were treated with azacitidine and lenalidomide and mutations analyses were performed at baseline and during the therapy. Results were then correlated to clinical outcome, overall survival (OS), leukemia-free-survival (LFS) and response to therapy. Collectively, 34/44 patients were considered evaluable for response, with an overall response rate of 76.25% (26/34 cases): 17 patients showed a durable response, 9 patients early lost response and 8 patients never responded. The most frequently mutated genes were ASXL1, TET2, RUNX1, and SRSF2. All patients early losing response, as well as cases never responding, acquired the same 3 point mutations during therapy, affecting respectively PIK3CD (D133E), AKT3 (D280G), and PLCG2 (Q548R) genes, that regulate cell proliferation and differentiation. Moreover, Kaplan–Meier analyses revealed that this mutated cluster was significantly associated with a shorter OS, LFS, and duration of response. All in all, a common mutated cluster affecting 3 inositide-specific genes is significantly associated with loss of response to azacitidine and lenalidomide therapy in higher risk MDS. Further studies are warranted to confirm these data and to further analyze the functional role of this 3-gene cluster.

In recent years, dermatologic manifestations in oncohematologic patients have become more common. The aim of our study was to determine the incidence and heterogeneity of skin manifestations in patients followed at our Hematology Department. This observational monocentrical study was conducted on 60 patients. We divided the observed conditions in exanthematous, purpuric, vesicular-bullous, papulonodular, urticarial, and eczematous manifestations. Moreover, all lesions were classified according to pathogenesis, in (a) specific skin manifestations, caused by neoplastic skin infiltration; (b) immune-mediated manifestations, based on immunological mechanisms; and (c) skin lesions due to immunodeficiency. Altogether, 73 clinical manifestations were reported. Specific manifestations (a) were detected in 15.1% of the cases, mainly with papulonodular appearance. Immune-mediated manifestations (b) were found in 37 cases (50.7%), particularly with eczematous or exanthematous appearance, and leukemia was the malignancy most frequently reported in these patients. Eventually, lesions due to immunosuppression (c) were reported in 34.2% of the cases. They were represented by infections and cutaneous malignancies, and usually manifested with papulonodular lesions. Skin lesions in oncohematologic patients are a common event. A multidisciplinary approach based on the collaboration between the hematologist and the dermatologist is crucial to achieve a proper diagnosis, and correctly manage these manifestations.

Background Blastic plasmacytoid dendritic cell neoplasm (BPDCN) are a very rare group of diseases included by WHO 2016 classification among the myeloid neoplasms and usually display an aggressive course with dismal outcome. BPDCN are characterized by a recurrent phenotype (CD45low/CD34-/CD56+/CD4+/CD123+), in the absence of other lineage differentiation markers. Our group recently reported that a subset of patients diagnosed with AML with NPM1-mutation carrying co-expression of CD123, CD56 and CD4, a "BPDCN-like" phenotype, showed poor prognosis. The aim of the present study was to evaluate the incidence and the prognostic impact of BPDCN-like phenotype in a wider cohort of cytogenetically normal AML patients, irrespectively of NPM1-mutational status. Methods We retrospectively evaluated a cohort of 83 younger (age In all patient, 4 (until 2012) or 8 color immunophenotypic analysis was performed at diagnosis by analysing erythrocyte-lysed whole BM blasts to identify relevant antigen aberration patterns and the pathological leukemia phenotype for future minimal residual disease assessment. We defined a BPDCN-like signature the positivity of at least two among CD56/CD4/CD123 antigens and we evaluated the prognostic impact and the correlation with biological, molecular and cytogenetic features. Results Fifteen patients (18%) showed a BPDCN-like signature. Neither the presence of NPM1-mutation nor FLT3-ITD or biallelic CEBPA mutation showed a significant correlation with BPDCN-like signature. BPDCN-like patients had significantly higher WBC count at diagnosis (p Among analyzed variables, only the presence of NPM1-mutation correlated with complete response (CR) probability. With a median follow-up of 63 months, 3-year Overall Survival (OS) was 52% in the whole cohort (median 38 months). Patient with NPM1 mutation or biallelic CEBPA mutation had a better outcome (p However, as we previously reported, in the subgroup of 30 patients with NPM-1 mut AML, the presence of BPDCN-like features conferred a poor prognosis (3-year OS 25% vs 77% for BPDCN positive and negative NPM-1 mut patients, respectively, p On the contrary in the 38 NPM-1 wt patients a trend towards better outcome was observed in BPDCN-like patient, unless not statistically significant (3-year OS 71% vs 35% for BPDCN-like positive and negative NPM-wt patients, respectively, p=0.156). No difference in MRD clearance probability was observed in this subgroup. Conclusions Our extended analysis confirms that a peculiar BPDCN-like immunophenotype among NPM-1 mut AML patients is associated with significantly worse outcome in this otherwise favorable subset of AML. Patient with BPDCN-like features showed high level of minimal residual disease after induction, suggesting an intrinsic chemo-resistance. Interestingly, this observation was strictly restricted to NPM-1 mutated AML, suggesting that peculiar alterations in this distinct entity contribute to the prognostic impact of BPDCN-like features in this setting. The biological explanation of this finding is not clear and further gene-expression profiling studies are ongoing in order to explain our findings. Figure. Figure. Disclosures Gobbi: Pfister: Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; Ariad: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy.

Purpose To investigate the progression-free survival (PFS) of patients with advanced Hodgkin lymphoma (HL) after a risk-adapted treatment strategy that was based on a positive positron emission tomography scan performed after two doxorubicin, vinblastine, vincristine, and dacarbazine (ABVD) cycles (PET2). Patients and Methods Patients with advanced-stage (IIB to IVB) HL were consecutively enrolled. After two ABVD cycles, PET2 was performed and centrally reviewed according to the Deauville five-point scale. Patients with a positive PET2 were randomly assigned to four cycles of escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP) followed by four cycles of standard BEACOPP with or without rituximab. Patients with a negative PET2 continued ABVD, and those with a large nodal mass at diagnosis (≥ 5 cm) in complete remission with a negative PET at the end of chemotherapy were randomly assigned to radiotherapy or no further treatment. The primary end point was 3-year PFS. Results Of 782 enrolled patients, 150 (19%) had a positive and 630 (81%) a negative PET2. The 3-year PFS of all patients was 82%. The 3-year PFS of those with a positive and negative PET2 was 60% and 87%, respectively ( P < .001). The 3-year PFS of patients with a positive PET2 assigned to BEACOPP with or without rituximab was 63% versus 57% ( P = .53). In 296 patients with both interim and post-ABVD–negative PET who had a large nodal mass at diagnosis, radiotherapy was randomly added after chemotherapy without a significant PFS improvement (97% v 93%, respectively; P = .29). The 3-year overall survival of all 782 patients was 97% (99% and 89% for PET2 negative and positive, respectively). Conclusion The PET-driven switch from ABVD to escalated BEACOPP is feasible and effective in high-risk patients with advanced-stage HL.

BACKROUND Hodgkin lymphoma (HL) is a lymphoid malignancy of B-cell origin with a high long-term survival. Despite the efficacy of frontline therapy, about 30% of patient will show relapse or refractory disease (R/R). In this patient population, the treatment of choice consists of salvage chemotherapy followed by intensive conditioning regimen and autologous stem cell transplantation (ASCT). However 30-50% of patients receiving salvage chemotherapy fail to achieve at least PR and further therapy with Brentuximab-Vedotin (BV) may be administered to induce a clinical response. Nonetheless, therapeutic options for truly refractory patients are still limited. Recently, immune-check point inhibitors have shown promising results in HL patients relapsed after ASCT. Anti-PD1 Nivolumab is currently approved with this indication. Unfortunately,expected CR rate is only about 20%.Thus, we reasoned that earlier administration of Nivolumab, as post-ASCT consolidation, might improve its efficacy. However, several reports have highlighted the importance of patient immune-competence, which is severely impaired in heavily pre-treated lymphoma patients undergoing ASCT, to achieve durable response with anti-PD1 immunotherapy. AIMS OF THE STUDY Here we report the preliminary results of a prospective trial investigating the feasibility, and the efficacy, in terms of both immunological recovery andclinical response,ofthe reinfusion of autologous lymphocytes (ALI), early after ASCT, concomitant with anti-PD1 consolidation immunotherapy in very high-risk HD patients. METHODS Patients under the age of 60 with high risk HD identified by PET2 or PET6 positivity following ABVD were scheduled for a pre-emptive lymphocyte apheresis with a target of 5x107 CD3+/kg. Patients who failed to achieve at least PR with salvage chemotherapy proceeded to ASCT with FEAM conditioning followed by early Nivolumab and ALI.The first ALI was performed 7 days after engraftment; the second ALI was administered at day +14 after the first dose whereas the third and the fourth doses were given every 21 days. ALI dosing was incremental, one logarithm at each infusion, starting from 1x104CD3+ cells/kg in the first infusion to a maximum of 1x107/kg in the fourth and last infusion. Each ALI was followed within 48 hours by the administration of Nivolumab 240 mg flat dose. Toxicity was evaluated and graduated according to CTCAE-EORTC standards. Circulating lymphocyte subpopulationswere extensively studied before and after each ALI and each Nivolumab administration by 12-colours flow cytometry. Clinical response was evaluated 21 days after completion of the fourth ALI + Nivolumab. PRELIMINARY RESULTS Four R/R HD patients have completed the treatment and3are currently under treatment. All patientshad failed to achieve CR with first and second line chemotherapy. PET scan before ASCT showed progressing disease in all patients despite BV therapy, with multiple-extra nodal involvement in 3 of them. Study patients underwent ASCT with FEAM conditioning and achieved complete engraftment after a median of 10 days (8-12). ALI induced faster T-cell recovery (p PRELIMINARY CONCLUSIONS Post-ASCT ALI proved to be feasible and effective allowing a faster immune recovery in heavily-pre-treated HD patients. Moreover, the early administration of check point inhibitors combined with ALI as post-ASCT consolidation therapy, may improve the low rate of CR expected with anti-PD1 blockade alone, providing a more effective option for refractory patient, which are usually considered not candidate for ASCT. Figure 1. Figure 1. Disclosures Gobbi: Amgen: Consultancy; Ariad: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; Pfister: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy.

Acute myeloid leukemia (AML) is the most common form of acute leukemia affecting adults. Although it is a complex disease driven by numerous genetic and epigenetic abnormalities, nearly 50% of patients exhibit a normal karyotype (CN-AML) with an intermediate cytogenetic risk. However, a widespread genomic analysis has recently shown the recurrence of genomic aberrations in this category (mutations of FLT3, CEBPA, NPM1, RUNX1, TET2, IDH1/2, DNMT3A, ASXL1, MLL and WT1) thus revealing its marked genomic heterogeneity. In this perspective, a global gene expression analysis of AML patients provides an independent prognostic marker to categorize each patient into clinic-pathologic subgroups based on its molecular genetic defects. Consistently such classification, taking into account the uniqueness of each AML patient, furnishes an individualized treatment approach leading a step closer to personalized medicine. Overall the genome-wide analysis of AML patients, by providing novel insights into biology of this tumor, furnishes accurate prognostic markers as well as useful tools for selecting the most appropriate treatment option. Moreover it provides novel therapeutic targets useful to enhance efficacy of the current anti-AML therapeutics. Here we describe the prognostic relevance of such new genetic data and discuss how this approach can be used to improve survival and treatment of AML patients.

Background: The addition of the anti-CD33 targeting antibody Mylotarg (MY) to conventional "3+7" induction has been shown to improve the outcome of patients affected by acute myeloid leukemia (AML) without adverse cytogenetic alterations. Early reports suggested that MY was particularly effective among low risk patients, such as core binding factor AML, particularly if included in a high dose cytarabine-based induction therapy. The role of MY for intermediate risk patients appears to be less clear. Cytogenetically defined intermediate risk patients may be further stratified considering two frequent molecular aberrations: FLT3 "internal tandem duplication" (FLT3-ITD) mutation, associated with poor prognosis and NPM1 mutation (NPM1-mut), associated with a good prognosis. The concomitant presence of NPM1-mutpartially overcomes the negative prognostic impact of FLT3-ITD, which is also modulated by FLT3-ITD/wild type allelic ratio. NPM1 and FLT3 mutational status assessment is strongly recommended for risk stratification at diagnosis by the last ELN 2017 guidelines. Aims: To investigate the efficacy of MY added to an intensive fludarabine, high dose cytarabine and Idarubicin-based induction regimen (FLAI) as frontline treatment for younger ( Methods:One-hundred and forty eight consecutive AML patients, treated in 3 Italian Hematology centersbetween 2008 and 2018and harboring at least one molecular alteration among NPM1-mut and FLT3-ITD, were included in the analysis. Thirty three patients carried isolated FLT3-ITD, 50patients showed concomitant FLT3-ITD and NPM1-mut and 65 isolated mutated NPM-1.Median age was 50 years(range: 18-65). All patients received FLAI induction (fludarabine 30 mg/sqm and ARA-C 2g/sqm on days1 to 5 plus idarubicin 10 mg/sqm on days 1-3-5), with or without low dose MY(3 mg/sqm, added in 42 patients), followed by a second induction without fludarabine and with idarubicin at the increased dose of 12 mg/sqm. Before 2017, patients with isolated FLT3-ITD mutation were scheduled for allogeneic stem cell transplantation (HSCT), if an HLA-matched sibling donor was available, whereas after 2017 only patients with high allelic burden isolated FLT3-ITD mutation received HSCT in first CR. The other patients received conventional high dose cytarabine consolidation for a total of 3 cycles. Results: Overall, 60-days mortality was 3%, and was not significantly influenced by receiving or not MY during induction. After one induction cycle, 126 patients achieved CR (85%) with no difference between patients receiving or not MY. After a median follow up of 70months, 3-year overall survival (OS) was 59.5% (median not reached). OS duration was significantly longer in NPM1 mutated patients (p Conclusions: Despite the potential bias due to the retrospective nature of the analysis, our data seem to indicate that Mylotarg, added to an intensive fludarabine/high dose cytarabine-based induction, provides a significant improvement in anti-leukemic efficacy in patients carrying FLT3-ITD mutation, especially if concomitant NPM1 mutation is not present. Disclosures Candoni: Gilead: Honoraria, Speakers Bureau; Celgene: Honoraria; Pfizer: Honoraria; Janssen: Honoraria; Merck SD: Honoraria, Speakers Bureau. Bocchia:Novartis: Honoraria; Incyte: Honoraria; BMS: Honoraria.

Introduction : The myelodysplastic syndromes (MDS) are a group of clonal haematopoietic stem cell disorders and they can be a consequence of genomic/chromosomal instability. The World Health Organization (WHO) 2008 classification divides the MDS in 4 types: refractory anaemia with excess of blast (RAEB), refractory anaemia (RA), refractory cytopenia with multilineage dysplasia (RCMD) and chronic myelomonocytic leukaemia (CMML). Various mechanisms contribute to the pathogenesis and prognosis of the disease and currently next generation sequencing (NGS) detects pathogenic gene mutations that can allocate patients to different risk classes. MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression via post-transcriptional mechanisms and may have oncogenic properties or act as tumour suppressor and have an active role in the onset of myeloid disorders. A prospective study based on integration of NGS and miRNA quantification was launched at Policlinico San Martino in 2017. The aim of this paper is to report the results and the correlation with the clinical features. Patients and methods: 28 consecutive patients were enrolled in this study because they met our eligibility criteria: (i) availability of bone marrow sample at diagnosis, (ii) IPSS and (iii) clinical follow up. Specifically, 11 patients were affected by RAEB, 9 by RA, 5 by RCMD and 3 by CMML. Median age was 66 years old (48 - 85). Eight patients evolved into acute myeloid leukaemia. NGS analysis was performed with Myeloid Oncomine Panel Thermo fisher; miRNA expression was quantified with TaqMan Advanced miRNA Cards. In the context of a machine learning supervised analysis we evaluated if there were significant differences in the miRNAs expression among the patients classified based on the WHO 2008 classification. This analysis was conducted using l1l2-penalized regularization method within PALLADIO, a machine-learning framework that can provide robust variable selection in high-dimensional problems. The identified miRNA signature was characterized though a miRNA enrichment analysis using the webtoolkit WebGestalt. Results: each patient carried a distinctive miRNA signature composed by a median of 650 miRNA. The supervised analysis identified a signature of 24 miRNAs (table 1) able to discriminate the 4 WHO classes with a balanced accuracy of 0.616 (whose significance with respect to the balanced accuracy distribution of the permutation batch experiments has 2.206e-08 p-value). Among these miRNAs, 14 were selected because frequently up-regulated in most the patients of one or more WHO classes (figure 1). NGS identified mutations in 43% of patients affected by RAEB, RCMD and CMML in genes known to be pathogenic for MDS (figure 2). miRNA enrichment analysis allowed the identifications of genes involved in (i) pathways (some in common and some specific for a WHO class) likely involved in the onset of MDS, (ii) in diseases related to MDS and to disease evolution into acute myeloid leukaemia. Some of these genes were the same with the ones identified by NGS in our study population (i.e. TET2, ASLX1, RUNX1, IKZF1, SRSF2) but many others (e.g., GATA2, NfkB, BCL2, CD46, mTOR) were not detected by NGS but are likely to be involved in MDS pathogenesis and disease progression as described previously by other groups (figure 3). C onclusions : our study gives a further input toward the understanding of pathogenesis in MDS through the integration of miRNA analysis with NGS at the diagnosis of MDS. With the identification of specific miRNA signature for each patient it is possible to highlight multiple genes pathway that may contribute to the onset and progression of MDS. In a prospective trial we also aim to verify if a specific miRNA signature is linked to azacitidine resistance. Disclosures Mufti: Celgene: Consultancy, Research Funding.

Background: The presence of FLT3 "internal tandem duplication" (FLT3-ITD) mutation is associated with poor prognosis in acute myeloid leukemia (AML). However, the concomitant presence of NPM1 mutation (NPM1-mut) partially overcomes the negative prognostic impact of FLT3-ITD, which is also modulated by FLT3-ITD/wild-type allelic ratio. NPM1 and FLT3 mutational status assessment is strongly recommended for risk stratificationat diagnosis by the last European Leukemia Net (ELN) guidelines. Aims: To investigate the efficacy of an intensive fludarabine-containing induction regimen (FLAI) for fit, de novo AML patients according to NPM1 and FLT3-ITD mutational status. Methods: One-hundred and sixteen consecutive AML patients, treated in 3 Hematology Italian centers from January 2008 to January 2018, were included in this analysis. Twenty five patients showed isolated FLT3-ITD, 39 concomitant FLT3-ITD and NPM1-mutation and 52 isolated NPM-1-mutation.Median age was 52 yrs (range: 18-65 years). All patients received fludarabine, high dose cytarabine-based induction (fludarabine 30 mg/sqm and ARA-C 2g/sqm ondays 1 to 5 plus idarubicin 10 mg/sqm on days 1-3-5). For patients achieving CR fludarabine was omitted on II induction course and idarubicin dose was increased to 12 mg/sqm. Before2017 patients with isolated FLT3-ITD mutation were scheduled to receive allogeneic bone marrow transplantation (BMT) in first complete remission regardless of allelic burden whereas after 2017 only patients with high allelic burden received BMT in 1st CR. Minimal residual disease was evaluated on marrow samples using multicolor flow-cytometry (MFC)or NPM1 expression levels. Negative MFC-MRD wasdefined by the presence of less than 25 clustered leukemic cells/105 total events (threshold of 0.025% residual leukemic cells, Minetto et. al, BJH 2019). NPM1mutation (NPM1-A, B and D) was measured using Muta Quant Kit Ipsogen from Qiagen. FLT3-ITD allelic burden was available in31/64 of FLT3-ITD patients. Results: Overall 60-days mortality was 4%. After two induction cycles, 101 patients achieved CR (87%). Thirty-three/101 (33%) CR patients underwent BMT in first CR. After a median follow up of 61 months, 3-year overall survival (OS) was 56.8% (median not reached). In univariate analysis OS duration was favorably affected by age Conclusion: Despite the potential bias due to the retrospective nature of the analysis, our data indicate that intensive fludarabine-high dose cytarabine-based induction exerts a strong anti-leukemic efficacy in younger AML patients carrying NPM1 mutation irrespectively of FLT3 mutational status.Thus, the synergism of fludarabine and cytarabine seems to affect the intrinsic chemosensitivity of NPM1-mut leukemic cells, overcoming the negative impact of FLT3-ITD. Moreover, our data suggest the strong prognostic impact on survival of MRD clearance and question the role of BMT in I CR in this setting of patients. Figure 1 Disclosures Candoni: Gilead: Honoraria, Speakers Bureau; Celgene: Honoraria; Pfizer: Honoraria; Janssen: Honoraria; Merck SD: Honoraria, Speakers Bureau. Bocchia:Incyte: Honoraria; Novartis: Honoraria; BMS: Honoraria.

Skeletal erosion has been found to represent an independent prognostic indicator in patients with advanced stages of chronic lymphocytic leukaemia (CLL). Whether this phenomenon also occurs in early CLL phases and its underlying mechanisms have yet to be fully elucidated. In this study, we prospectively enrolled 36 consecutive treatment-naïve patients to analyse skeletal structure and bone marrow distribution using a computational approach to PET/CT images. This evaluation was combined with the analysis of RANK/RANKL loop activation in the leukemic clone, given recent reports on its role in CLL progression. Bone erosion was particularly evident in long bone shafts, progressively increased from Binet stage A to Binet stage C, and was correlated with both local expansion of metabolically active bone marrow documented by FDG uptake and with the number of RANKL + cells present in the circulating blood. In immune-deficient NOD/Shi-scid, γcnull (NSG) mice, administration of CLL cells caused an appreciable compact bone erosion that was prevented by Denosumab. CLL cell proliferation in vitro correlated with RANK expression and was impaired by Denosumab-mediated disruption of the RANK/RANKL loop. This study suggests an interaction between CLL cells and stromal elements able to simultaneously impair bone structure and increase proliferating potential of leukemic clone.

Acute Myeloid Leukemia (AML) is the commonest form of leukemia in the adults, with an incidence of 3-4 cases per 100,000 people/year. After the first description of the effective cytarabine + antracycline (3+7) induction regimen, in the last 3 decades, no effective targeted drug has been included in the standard treatment of AML. Many efforts of modifying 3+7 adding a third drug or increasing the dose of anthracycline, cytarabine or both did not lead to substantial improvements, mainly due to increased toxicity. Many in vitro and in vivo evidences suggested that fludarabine may increase efficacy of cytarabine through a synergistic effect. Considering the continuous improvements in supportive care and management of infectious complications the feasibility of more intensive induction strategies have increased and a renewed interest in fludarabine-containing induction strategies arose. The recent MRC AML 15 trial has shown that a fludarabine-containing induction, FLAG-Ida, resulted superior to conventional 3+7 in terms of complete remission rates, relapse incidence and survival, although only a minority of patients could complete the whole planned consolidation program due to an excessive hematological toxicity. Our group recently published a 10-year experience with a fludarabine-containing induction that slightly differed from the MRC one and resulted in good efficacy and higher feasibility. In this commentary we review the major evidences supporting the employ of a fludarabine-containing induction in AML, and discuss the future perspectives.

Fifty patients with high-risk hematologic malignancies, underwent an unmanipulated haploidentical bone marrow transplantation (BMT), followed by posttransplantation high-dose cyclophosphamide (PT-CY): the myeloablative (MA) conditioning consisted of thiotepa, busulfan, fludarabine (n = 35), or total body irradiation (TBI), fludarabine (n = 15). The median age was 42 years (range, 18-66 years); 23 patients were in remission, 27 had active disease, and 10 patients were receiving a second allograft. Graft-versus-host disease (GVHD) prophylaxis consisted in PT-CY on day +3 and +5, cyclosporine (from day 0), and mycophenolate (from day +1). Three patients died before engraftment, and 2 patients had autologous recovery: 45 patients (90%) had full-donor chimerism on day +30. The median day for neutrophil engraftment was day +18 (range, 13-30 days). The cumulative incidence of grade II-III acute GVHD (aGVHD) was 12%, and of moderate chronic GVHD (cGVHD) 10%. With a median follow-up for surviving patients of 333 days (range, 149-623 days), the cumulative incidence of transplantation-related mortality (TRM) was 18%, and the rate of relapse was 26%. The actuarial 22-month disease-free survival (DFS) rate was 68% for patients in remission and 37% for patients with active disease (P < .001). Causes of death were pneumonia (n = 3), hemorrhage (n = 3), sepsis (n = 3), and relapse (n = 7). In conclusion, an MA conditioning regimen followed by haploidentical BMT with PT-CY results in a low risk of aGVHD and cGVHD and encouraging rates of TRM and DFS.

Purpose: Nicotinamide phosphoribosyltransferase (Nampt) regulates intracellular NAD+ pool and is highly expressed in a number of malignancies. FK866, a selective inhibitor of Nampt, depletes intracellular NAD+ levels, thereby blocking cellular metabolism and triggering sensitization to other drugs and cell death. Here we characterized the antitumor effects of Nampt inhibition in Waldenström macroglobulinemia. Experimental Design: We investigated Nampt role in MW cells using both mRNA and protein expression analyses. We have also used loss-of-function approaches to investigate the growth and survival effects of Nampt on MW cells and further tested the anti-MW activity of dual Nampt and BTK inhibition in vitro and in vivo. Results: We found that Waldenström macroglobulinemia cells exhibit high levels of Nampt compared with normal B cells. Loss of function studies suggested a potential oncogenic role of Nampt in Waldenström macroglobulinemia cells, and BTK-inhibitor ibrutinib and FK866 resulted in a significant and synergistic anti-Waldenström macroglobulinemia cell death, regardless of MYD88 and CXCR4 mutational status. Cell death was associated with: (i) activation of caspase-3, PARP and downregulation of Mcl-1, (ii) enhanced intracellular ATP and NAD+ depletion, (iii) inhibition of NF-κB signaling, and (iv) inhibition of multiple prosurvival signaling pathways. In a murine xenograft Waldenström macroglobulinemia model, low-dose combination FK866 and ibrutinib is well tolerated, significantly inhibits tumor growth, and prolongs host survival. Conclusions: Our results show intracellular NAD+ level as crucial for proliferation and survival of Waldenström macroglobulinemia cells, and provides the mechanistic preclinical rationale for targeting Nampt, either alone or with Ibrutinib, to overcome drug resistance and improve patient outcome in Waldenström macroglobulinemia. Clin Cancer Res; 22(24); 6099–109. ©2016 AACR.

We compared the clinical value of minimal residual disease (MRD) monitoring by cytofluorimetric methods, Wilms tumor gene 1 (WT1) expression and the study of nucleophosmin gene (NPM) mutations in a series of 26 patients with NPM-mutated de novo acute myeloid leukemia (NPM-AML) who achieved complete hematological remission after conventional chemotherapy. The relapse risk was significantly lower only in patients achieving a NPM molecular complete response (NPM mol-CR) and confirmed NPM mol-CR (non-detectable NPM mutations in two consecutive marrow samples). The disease-free survival (DFS) of patients achieving a = 4-log reduction in NPM value after induction therapy was 12.6 % and 50%, respectively, at 36 months (p = 0.009). The attainment of a confirmed NPM-CR had a significant influence on overall survival (OS at 36 months was 64.3% and 11.9% in patients obtaining or not obtaining confirmed NPM-CR, respectively, p < 0.03). We confirm that NPM-molecular relapse (NPM-rel) is always followed by hematological relapse (H-rel), but longitudinal studies of NPM mutations may predict an impending H-rel earlier than flow cytometric- or WT1-based methods.

We reviewed the frequency and prognostic significance of FLT3 (fms-like tyrosine kinase receptor-3) and NPM (nucleophosmin) gene mutations and WT1 (Wilms' tumor) and BAALC (brain and acute leukemia, cytoplasmic) gene expression in 100 consecutive patients with intermediate and poor cytogenetic risk de novo acute myeloid leukemia (AML) receiving conventional anthracycline-AraC based therapy. We observed a strict relationship between unfavorable karyotype and BAALC1000 (p = 0.0001). Multivariate analysis of 81 patients with intermediate karyotype revealed that younger age (p = 0.00009), NPM gene mutation (p = 0.002), and WT175th percentile (2365) (p = 0.003) were independent, positive factors for complete remission (CR). WT1 expression above 2365 was correlated also to longer event-free survival (EFS) and overall survival (OS) in the same subset of patients (p = 0.003 and p = 0.02, respectively); the same finding occurred in younger patients with AML with intermediate karyotype (p = 0.008 and p = 0.01, respectively). In patients with intermediate karyotype, FLT3 internal tandem duplication (ITD) negatively affected EFS (EFS at 30 months: 30% vs. 6% in FLT3-ITD negative and FLT3 positive patients, respectively; p = 0.01) and OS (OS at 30 months: 38% vs. 20%, p = 0.03). The positive prognostic value of high WT1 expression does not have a clear explanation; it may be implicated either with WT1 anti-oncogenic function, or with the stimulating effect of WT1 oncogene on the leukemic cellular cycle, possibly associated with an enhanced response to chemotherapy.

Background: The application of pediatric-inspired regimens for the treatment of adult acute lymphoblastic leukemia (ALL) patients has led to a significant improvement in clinical outcome. The increased use of non-myelosuppressive agents such as peg-asparaginase (PEG-ASP) in modern adult protocols greatly contributed to improve treatment outcome. However, concerns about the safety of PEG-ASP administration in adults have emerged. Patient-related factors as high body mass index (BMI) or pre-exhistinghepatic steatosis have already been identified as risk factors contributing to PEG-ASP related toxicity. However, few data are available on the role of specific concomitant medications potentially contributing to PEG-ASP toxicity. Aims: To identify patients and therapy-related factors contributing to the development of PEG-ASP associated toxicity in a cohort of adult ALL patients who received intensive induction treatment according to a full pediatric or an alternative intensive regimen. Methods: Since 2013, 26 adult ALL patients received PEG-ASP in our Center. Median age was 47 years (range 19-76). Nineteen patients were treated in front-line setting: 11 according to the full pediatric protocol AIEOP-BFM 2009 (median age 36, range 19-56), 4 patients according to a national pediatric-like protocol for adult patients (median age: 47,5, range 39-59) and 1 patient aged 76 received PEG-ASP plus reduced-intensity chemo. Ten patients received PEG-ASP as part of salvage therapy for relapsed/refractory disease. Methods: PEG-ASP- related toxicities were recorded and classified according to the guidelines published by Stock et al (Leukemia and Lymphoma, 2011). The incidence of PEG-ASP-related toxicity was analyzed considering as a separate episode each course of therapy including PEG-ASP administration (with a median duration per episode of 1 month, range 0,5-2 months). Patient features, timing and doses of chemotherapic agents and concomitant medications were recorded. A total of 49 episodes were analyzed Results: No grade III-IV pancreatic, thrombotic or hemorrhagic adverse event were observed. Isolated hyperbilirubinemia was the most frequent adverse event observed (n. 24 grade II, N. 5 grade III, N. 2 grade IV). Grade III hepatotoxicity was observed in 5 patients; 3 patients had grade IV hepatotoxicity. In all of them, ultrasonography showed the onset of acute liver steatosis. All 3 patients had received concomitant therapy with Idarubicin (IDA), vincristine (VCR) and vancomycin. In all the 3 cases patients died due to superimposed infections. In univariate analysis age > 45 yrs, administration of PEG-ASP therapy with active leukemia or BMI >25 were not related with an increased incidence of grade III-IV hepatotoxicity which was instead significantly higher when a cumulative dose of IDA of at least 20 mg/sqm over a single episode (p 0.047, HR 1.48) was administered. Cumulative dose of VCR of at least 2 mg/sqm determined a borderline increase in toxicity risk (p 0.055, HR 4.75). Administration of estroprogestinic hormones were significantly associated with the risk of developing hepatic-toxicity (p 0.024, HR 1.33). No increase was observed with any dose of prednisone/dexametasone, daunorubicin, cyclophosphamide, cytarabine, methotrexate, and 6-mercaptopurine. Among antimicrobial therapies, vancomycin, synthetic penicillines + B-lactamases inhibitors and Carbapenems administration increased the risk of grade III-IV hepatotoxicity (p 0.009, HR 1.85, p 0.010 HR 3.02, p 0.047 HR 2.02). No significant increase in the risk of toxicity was observed with azoles. Notably, none of the patients undergoing full pediatric induction, which contains higher cumulative doses of PEG-ASP, experienced grade IV hepatotoxicity. A multivariate logistic regression analysis disclosed that administration of IDA, sexual hormones and synthetic penicillines + B-lactamases inhibitors were independent predictors of grade III/IV hepatotoxicity (p 0.014, 0.024, 0.041; Tab. I). Conclusion: In our experience the toxicity profile of PEG-ASP in adult patients is overall manageable even when high doses were administered according to a full pediatric schedule. Our data suggest that the development of severe hepatic toxicity is significantly influenced by chemotherapy schedule and specific concomitant medications. Disclosures Gobbi: Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy; Pfister: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; Ariad: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy.

We describe here a patient with Ph'-positive chronic myelogenous leukemia (CML) who developed a Ph'-negative blastic crisis. The blast DNA was analyzed on two different occasions, at the beginning of the blastic phase and at the end, shortly before the patient's death. Although cells from both samples had no Ph' chromosome marker (not even a masked one) we could detect a rearrangement of the bcr gene in the second DNA sample, using a '3'-bcr' probe. The same probe and a '5'-bcr' probe failed to detect any rearranged band in the first DNA sample. No rearrangement was identified at the c-myc and N-ras loci, while a slight c-myc amplification was evident in both DNA samples tested.

Minimal residual disease (MRD) was monitored by Wilms tumor 1 (WT1) expression in 207 patients with acute myeloid leukemia (AML) after an allogeneic hemopoietic stem cell transplantation (HSCT) as a trigger to initiate pre-emptive immunotherapy (IT) with cyclosporin discontinuation and/or donor lymphocyte infusion. The trigger for IT was WT1 ≥ 180 copies/104 Abelson cells in marrow cells in the first group of 122 patients (WT1-180) and ≥ 100 copies in a subsequent group of 85 patients (WT1-100). Forty patients received IT. The cumulative incidence (CI) of relapse was 76% in WT1-180 (n = 17) versus 29% in WT1-100 patients (n = 23) receiving IT (P = .006); the leukemia-free survival from MRD positivity was 23% versus 74%, respectively (P = .003). We then looked at the entire AML patient population (n = 207). WT1-180 and WT1-100 patients were comparable for disease phase and age. The overall 4-year CI of transplantation-related mortality was 13% in both groups; the CI of leukemia relapse was 38% in the WT1-180 and 28% in the WT1-100 patients (P = .05) and leukemia-free survival was 56% versus 48%, respectively (P = .07). In conclusion, we suggests that WT1-based pre-emptive immunotherapy is feasible in patients with undergoing an allogeneic HSCT. The protective effect on relapse is greater when IT is triggered at lower levels of WT1.

PURPOSE: To identify both clinical and FDG PET/CT-derived factors predicting the occurrence of relapse, or conversely, the likelihood of false positive findings in surveillance FDG-PET/CT studies (PETsv). METHODS: The study included 149 asymptomatic patients with Hodgkin's lymphoma (HL) (n = 55) or diffuse large B cell lymphoma (DLBCL) (n = 94) in first remission. PETSv studies were performed 12, 18, 24 and 36 months thereafter. Logistic regression analysis was performed to identify clinical and imaging-derived predictors of either PET-detected relapse or false-positive (FP) results. Tested clinical variables were: 1) age, 2) HL vs. DLBCL, 3) stage of disease, 4) bulky disease, 5) previous radiotherapy. PET/CT-derived variables were: 1) maximum standardized uptake value at baseline, 2) size-incorporated maximum standardized uptake value (SIMaxSUV) at baseline, 3) positive interim PET(PET-2), 4) presence of hot spots likely to be unrelated to the disease in final PET, 5) residual non-FDG avid mass. RESULTS: Accuracy was 88 % for PETsv1, 95 % for PETsv2, 95 % for PETsv3 and 91 % for PETsv4. However, PPV was relatively low in all PETsv. Best predictors of relapse were result of interim PET, HL versus NHL type, SIMaxSUV, age >= 60. Best predictors of FP were previous radiotherapy and hot spots unrelated to the disease in final PET. CONCLUSIONS: The present study confirms the need of restricting the use of surveillance PET/CT to patients at high risk of relapse. Information derived from PET/CT performed at baseline (metabolic disease burden), in the course (PET2) and at the end of therapy (unrelated hot spots) can help to select high-risk patients and also to identify patients more likely to present equivocal findings at PETsv.

To evaluate the safety and efficacy of pegfilgrastim administered as haematological support after autologous peripheral blood stem cell transplantation, we compared 44 patients with solid tumours and lymphomas receiving a 6-mg single dose of pegfilgrastim on day +5 after transplantation to a historical control group of 25 patients receiving filgrastim 5 microg kg(-1) day(-1) starting on day +5. There were no significant differences in haematological recovery nor in the incidence and duration of neutropenic fever. Median duration of grade 4 neutropenia in the pegfilgrastim and filgrastim group was similar. The incidence of grade III-IV mucositis was lower in pegfilgrastim than in filgrastim group due to the significant difference observed among the patients with solid tumours (p = 0.00). The only adverse event considered to be cytokine related was mild to moderate bone pain occurring during haematological recovery. According to the present study design and taking into account the current prices in our institution, the cost of the two drugs was similar in both treatment groups. In conclusion, a single injection of pegfilgrastim administered at day +5 post-transplantation shows comparable safety and efficacy profiles to daily injections of filgrastim and may be cost effective.

We assessed the outcome of 170 patients with AML in first complete remission, aged 1–47 years (median 29), who had undergone an allogeneic BMT before or after 1990 (n=80 and n=90, respectively); all patients were prepared with cyclophosphamide and TBI; the median follow-up for surviving patients was 13 years. The donor was an HLA-identical sibling in 164 patients. Transplant-related mortality (TRM) was 30% before and 7% after 1990 (P

Ongoing genomic instability represents a hallmark of multiple myeloma (MM) cells, which manifests largely as whole chromosome- or translocation-based aneuploidy. Importantly, although it supports tumorigenesis, progression and, response to treatment in MM patients, it remains one of the least understood components of malignant transformation in terms of molecular basis. Therefore these aspects make the comprehension of genomic instability a pioneering strategy for novel therapeutic and clinical speculations to use in the management of MM patients. Here we will review mechanisms mediating genomic instability in MM cells with an emphasis placed on pathogenic mutations affecting DNA recombination, replication and repair, telomere function and mitotic regulation of spindle attachment, centrosome function, and chromosomal segregation. We will discuss the mechanisms by which genetic aberrations give rise to multiple pathogenic events required for myelomagenesis and conclude with a discussion of the clinical applications of these findings in MM patients.

Background Peripheral T-cell lymphomas (PTCL) represent a heterogeneous group of hematologic malignancies frequently presenting at advanced stage of diagnosis. Methods We report a case of PTCL with an uncommon and aggressive onset with disseminated intravascular coagulation (DIC). Results Laboratory findings revealed an aberrant expression of β subunit of human chorionic gonadotropin (β-HCG). Other than for determination of pregnancy, β-HCG is regularly found as a tumor marker in germ cell tumors with trophoblastic differentiation and its aberrant expression has been reported in the literature in other neoplastic conditions only in the context of case reports. Conclusions In hematologic malignancies, β-HCG expression has been described only in sporadic cases. Awareness of this feature could avoid diagnostic delay in such an aggressive disease.

The aim of this study was to elucidate the relationship between clonal and normal haematopoiesis in chronic myelogenous leukemia (CML). Thirteen female patients who reached complete cytogenetic response (CCR) after Imatinib® treatment were studied. Although all the study patients exhibited a polyclonal pattern of X inactivation, p210 BCR/ABL transcript remained detectable in all cases by nested RT-PCR. This study also demonstrated the presence of p190 transcript in nine out of 13 study patients. A longer follow-up analysis is needed to clarify the prognostic value of these results. The recent observation that clonal cytogenetic abnormalities may occur in CML patients in polyclonal remission after imatinib suggests that a neoplastic stem cell lacking BCR/ABL rearrangement may acquire further cytogenetic alterations other than Philadelphia chromosome.

Sixty-two patients with high-risk acute leukemia were treated with the FLAD regimen [3 days of treatment with fludarabine 30 mg/m(2), cytarabine (AraC) 2 g/m(2), and liposomal daunorubicin 80 mg/m(2)]. The acute myeloid leukemia (AML) patients were either refractory to standard induction regimens (8), were in first or second relapse (13), or received therapy as first-line treatment [21 patients, 16 were above 60 years of age and 5 had post-myelodysplastic syndrome (MDS) AML]. The acute lymphoblastic leukemia (ALL) patients were treated for relapsed (7) or refractory disease (10). Three patients had chronic myeloid leukemia (CML) in the blastic phase. FLAD was well tolerated by most patients. Ten major infectious complications were recorded while no signs of cardiac toxicity were observed. Five patients (8%) died before day 28 with hypocellular marrow, mainly of infection or hemorrhage, and response could not be evaluated. Complete response rate was 62% and 69% among AML patients treated at diagnosis or for relapsed disease, respectively, and 59% among the ALL patients. Furthermore, FLAD managed to overcome the negative impact of poor prognosis karyotype in ALL patients, since five of the seven patients with t(9;22) or complex karyotype achieved complete remission (CR). Nine patients underwent bone marrow transplantation (BMT). Among the AML patients who were treated at diagnosis or for relapse, the median duration of CR was 7 months (range: 2-18) and 8 months (range: 2-26), respectively. Median survival among these patients was 8 (range: 1-40) and 12 (range: 1-30) months, respectively. Similar values were found in ALL patients. In conclusion, FLAD may be an effective alternative treatment for patients with relapsed AML and for patients with ALL who failed first-line therapy.

Abstract 4029 Background: Azacitidine (AZA) at a dose of 75 mg/mq/day subcutaneously for 7 days, every 28 days, induces high hematologic response rates and prolongation of survival in high-risk MDS patients (pts) (Fenaux, 2009). However few data are hitherto available concerning the efficacy and safety of Aza in lower risk MDS. A lower dose regimen, AZA 5 (75 mg/mq daily, subcutaneously, for 5 consecutive days every 4 weeks) have shown to induce response rates consistent with the currently approved schedule (Lyons, 2009), however in this study pts were not classified according to IPSS risk. Aim: The use of AZA in the earlier phases of disease could be more effective and useful to control the expansion of MDS clone and disease progression. In our phase II, prospective, multicentric trial, AZA 5 regimen was administered to IPSS low-or-intermediate-1 risk pts, for a total of 8 courses, in order to evaluate its efficacy and safety. Furthermore pharmacogenomic studies (GEP, SNP) cytokine network and PI-PLC-beta1 methylation and gene expression, before and at the end of 4th and 8th course of Aza treatment, were planned to identify new biological markers to predict the response. Methods: From September 2008 to February 2010, 34 patients (24 males, 10 females), with a median age of 71 (56-84) yrs, with symptomatic transfusion-dependent anemia, previously unresponsive to erythropoietin (EPO) or not expected to respond to EPO, or with severe neutropenia or thrombocytopenia, were enrolled into the study. According to WHO classification, 15 pts had RA, 6 RARS, 7 RCMD and 6 RAEB-1. Results: At present time 30/34 pts are evaluable: 23/30 pts (77%) completed the treatment plan (8 courses), 3/30 pts (10%) are ongoing and 4/30 (13%) died during the treatment period. According to the 2006 International Working Group criteria, overall response rate (ORR) was 60,9 % (14/23 pts): 5 pts (21,7%) achieved complete remission (CR), while 9 pts (39,1%) showed an hematologic improvement (HI) (7 erythroid responses, 1 erythroid/platelet response and 1 neutrophil/platelet response). 9/23 pts (39%) maintained a stable disease (SD). Generally the drug was very well tolerated. The most commonly reported hematologic toxicities were neutropenia (55%) and thrombocytopenia (19%). 4 pts (11,7%) died during treatment (2 pts after the 1th cycle and 2 pts after the 4th course) because of septic shock, gastrointestinal hemorrage, pneumonia, and respiratory distress, respectively. The median duration of response was 3,5 months (range 1–14 months). Surprisingly, 3/14 patients (2 CR and 1 HI erythroid) showed a long duration of response (11, 13 and 14 months, respectively), still ongoing, after discontinuation of AZA. Preliminary data on the lipid signalling pathways suggested a direct correlation between the demethylating effect on PI-PLC-beta1 and responsiveness to treatment. Conclusion: Our study shows that AZA low-dose schedule may be a feasible and effective treatment for low-risk MDS pts and may induce durable responses. Despite AZA safety, extreme caution is needed in pts with age-related comorbidities and/or with severe neutropenia or thrombocytopenia, especially in low-risk MDS. Furthermore, PI-PLC–β1 demethylation and gene expression could represent a new biological marker to predict the clinical response to AZA Disclosures: Off Label Use: In Italy the use of Azicitidine for Low-Risk Myelodysplastic patients is off-label. The use of azacitidine in our study is part of a Phase II clinical trial. Finelli:Celgene: Consultancy.

We developed a PCR-based method to monitor clonogenic IgH VDJ rearrangement as a possible predictor of relapse in patients with acute B-ALL after allogeneic bone marrow transplantation (BMT). We studied 23 patients at diagnosis, before and after BMT. At the time of BMT, 13 patients were in first complete remission, eight in second complete remission and two in relapse. Four patients were PCR negative before BMT and remained PCR negative also after BMT (-/- pattern). They are still in remission after a median follow-up of 41 months. Nineteen patients were MRD-positive before BMT: three were PCR negative at first determination after BMT (+/- pattern) and maintain remission. Sixteen patients were PCR-positive at first determination after BMT (+/+ pattern): five became PCR negative (+/+/- pattern) (four with chronic graft-versus-host disease (GVHD) and two after donor lymphocyte infusions (DLI)). Nine patients remained PCR-positive (+/+/+ pattern) (four remain in remission, and six relapsed); two patients died before transplant. In conclusion, PCR negative patients before BMT remained negative post-BMT; many pre-BMT positive patients had initial MRD positivity after BMT: 37% of them achieved a molecular remission with cGVHD or DLI.