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Purpose: The nicotinamide phosphoribosyltransferase (NAMPT) inhibitor, APO866, has been previously shown to have antileukemic activity in preclinical models, but its cytotoxicity in primary leukemia cells is frequently limited. The success of current antileukemic treatments is reduced by the occurrence of multidrug resistance, which, in turn, is mediated by membrane transport proteins, such as P-glycoprotein-1 (Pgp). Here, we evaluated the antileukemic effects of APO866 in combination with Pgp inhibitors and studied the mechanisms underlying the interaction between these two types of agents.Experimental Design: The effects of APO866 with or without Pgp inhibitors were tested on the viability of leukemia cell lines, primary leukemia cells (AML, n = 6; B-CLL, n = 19), and healthy leukocytes. Intracellular nicotinamide adenine dinucleotide (NAD+) and ATP levels, mitochondrial transmembrane potential (ΔΨm), markers of apoptosis and of endoplasmic reticulum (ER) stress were evaluated.Results: The combination of APO866 with Pgp inhibitors resulted in a synergistic cytotoxic effect in leukemia cells, while sparing normal CD34+ progenitor cells and peripheral blood mononuclear cells. Combining Pgp inhibitors with APO866 led to increased intracellular APO866 levels, compounded NAD+ and ATP shortage, and induced ΔΨm dissipation. Notably, APO866, Pgp inhibitors and, to a much higher extent, their combination induced ER stress and ER stress inhibition strongly reduced the activity of these treatments.Conclusions: APO866 and Pgp inhibitors show a strong synergistic cooperation in leukemia cells, including acute myelogenous leukemia (AML) and B-cell chronic lymphocytic leukemia (B-CLL) samples. Further evaluations of the combination of these agents in clinical setting should be considered. Clin Cancer Res; 21(17); 3934–45. ©2015 AACR.

Supplemental Figures 1-8. Figure 1S: A) Nampt locus (human chromosome 7q22.3) copy number heatmap for lines included in the Cancer Cell Line Encyclopedia. B) mRNA Nampt expression plotted vs. DNA copy number (log2 ratio). Figure 2S: effect of APO866 combined plus FK506 on Mec.1 cell lines. Figure 3S: intracellular APO866 determination in primary B-CLL cell extract. Figure 4S: anti-tumor activity of APO866 combined with Pg-p inhibitors (CsA, Verapamil and Nilotinib) on primary B-CLL and AML cells. Figure 5S: effects of drugs combination on healthy PBPCs (A) and PBMCs (B) cells. Figure 6S: intracellular NAD+(H) and ATP levels measured in AML cells following drugs combination. Figure 7S: relative expression of WBs showed in Figure 6B. Figure 8S: effects of NA addition on anti-tumor activity of APO866 combined with PgP inhibitors and schematic representation of proposed model.

Here we report a case of a 32-year-old man, who was diagnosed as having chronic myeloid leukaemia in 1998. After cytoreduction with hydroxyurea, the patient was submitted to high dose chemotherapy with haemopoietic stem cells rescue and reinfusion, and then he started therapy with IFNα without achievement of a cytogenetic response. On November 2000 he took imatinib 400 mg/day and he reached a complete cytogenetic response (CCyR) at 14 months, but not the major molecular response: therefore he was considered a sub-optimal responder according to European LeukemiaNet criteria of 2006. For this reason he increased imatinib dose to 800 mg/day, but after one year he lost CCyR. Considering the patient as a failure, at this time, he switched to second-generation tyrosine kinase inhibitor, nilotinib at the dose of 800 mg/day. After 3 months he reached complete CCyR and after 6 months the major molecular response, maintained until last molecular evaluation.

Imatinib is effective for the treatment of chronic myeloid leukemia (CML). However even undetectable BCR-ABL1 by Q-RT-PCR does not equate to eradication of the disease. Digital-PCR (dPCR), able to detect 1 BCR-ABL1 positive cell out of 10(7) , has been recently developed. The ISAV study is a multicentre trial aimed at validating dPCR to predict relapses after imatinib discontinuation in CML patients with undetectable Q-RT-PCR. CML patients under imatinib therapy since more than 2 years and with undetectable PCR for at least 18 months were eligible. Patients were monitored by standard Q-RT-PCR for 36 months. Patients losing molecular remission (two consecutive positive Q-RT-PCR with at least 1 BCR-ABL1/ABL1 value above 0.1%) resumed imatinib. The study enrolled 112 patients, with a median follow-up of 21.6 months. Fifty-two of the 108 evaluable patients (48.1%), relapsed; 73.1% relapsed in the first 9 months but 14 late relapses were observed between 10 and 22 months. Among the 56 not-relapsed patients, 40 (37.0% of total) regained Q-RT-PCR positivity but never lost MMR. dPCR results showed a significant negative predictive value ratio of 1.115 [95% CI: 1.013-1.227]. An inverse relationship between patients age and risk of relapse was evident: 95% of patients 45 years, dPCR-). Imatinib can be safely discontinued in the setting of continued PCR negativity; age and dPCR results can predict relapse.

Interferon a (IFNa) prolongs survival of CML patients achieving CCyR and potentially synergizes with TKIs. We report on the molecular status and long term outcome of 121 patients who were treated in Italy between 1986 and 2000 with IFNa based therapy and who obtained CCyR. After a median follow up of 16.5 years, 74 (61%) patients were switched to standard imatinib: 48 (65%) lost the CCyR on IFNa, and 36 (75%) are alive and in CCyR; 26 (35%) were switched to imatinib when they were still in CCyR on IFNa, and all 26 are alive and in CCyR. Forty-seven patients (39%) were never switched to imatinib: 24 (51%) continued and 23 (49%) discontinued IFNa, respectively, and 39/47 (83%) are alive and in CCyR. At last follow-up, the BCR-ABL transcripts level was available in 96/101 living patients (95%) The BCR-ABL:ABL ratio was between 0.1 and 0.01% (MR 3.0 ) in 17%, and less than 0.01% (MR 4.0 ) in 81% of patients. No patient was completely molecular negative (MR 4.5 or MR 5.0 ). The OS at 10 and 20 years is 92 and 84%, respectively. This study confirms that CCyR achieved with IFNa and maintained with or without imatinib or any other therapy significantly correlates with long term survival in CML patients who mostly have MR 4.0 . Complete molecular response (MR 4.5 or MR 5.0 ) seems to be unnecessary for such a long survival. This study further supports development of studies testing the clinical effect of the combinations of TKIs with IFNa. Am. J. Hematol. 89:119–124, 2014. V C 2013 Wiley Periodicals, Inc.

In this study, we analyzed the influence of mesenchymal stromal cells derived from lymph nodes of non-Hodgkin’s lymphomas, on effector functions and differentiation of Vdelta (δ)2 T lymphocytes. We show that: i) lymph-node mesenchymal stromal cells of non-Hodgkin’s lymphoma inhibit NKG2D-mediated lymphoid cell killing, but not rituximab-induced antibody-dependent cell-mediated cytotoxicity, exerted by Vδ2 T lymphocytes; ii) pre-treatment of mesenchymal stromal cells with the aminobisphosphonates pamidronate or zoledronate can rescue lymphoma cell killing via NKG2D; iii) this is due to inhibition of transforming growth factor-β and increase in interleukin-15 production by mesenchymal stromal cells; iv) aminobisphosphonate-treated mesenchymal stromal cells drive Vδ2 T-lymphocyte differentiation into effector memory T cells, expressing the Thelper1 cytokines tumor necrosis factor-α and interferon-γ. In non-Hodgkin’s lymphoma lymph nodes, Vδ2 T cells were mostly naïve; upon co-culture with autologous lymph-node mesenchymal stromal cells exposed to zoledronate, the percentage of terminal differentiated effector memory Vδ2 T lymphocytes increased. In all non-Hodgkin’s lymphomas, low or undetectable transcription of Thelper1 cytokines was found. In diffused large B-cell lymphomas and in a group of follicular lymphoma, transcription of transforming growth factor β and interleukin-10 was enhanced compared to non-neoplastic lymph nodes. Thus, in non-Hodgkin lymphomas mesenchymal stromal cells interfere with Vδ2 T-lymphocyte cytolytic function and differentiation to Thelper1 and/or effector memory cells, depending on the prominent in situ cytokine milieu. Aminobisphosphonates, acting on lymph-node mesenchymal stromal cells, can push the balance towards Thelper1/effector memory and rescue the recognition and killing of lymphoma cells through NKG2D, sparing rituximab-induced antibody-dependent cell-mediated cytotoxicity.

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.

Engagement of NKG2D by their ligands (NKG2D-L), as the human major histocompatibility complex class I-related molecules MIC-A and the UL16-binding proteins, on cytolytic lymphocytes leads to the enhancement of antitumour effector functions. These ligands are missing or expressed at very low levels on leukaemic cells; furthermore, they can be shed by tumour cells and inhibit cytolytic activity of lymphocytes. Herein, we show that in vivo administration of all-trans-retinoic acid (ATRA) or the histone deacetylase inhibitor sodium valproate (VPA) to patients affected with acute myeloid leukaemia (AML) M3 or M1 respectively, leads to the induction of transcription and expression of NKG2D-L at the surface of leukaemic cells. Apparently, no detectable shedding of the soluble form of these molecules was found in patients' sera. Conversely, AML blasts from patients treated with chemotherapy not including ATRA or VPA did not show any induction of NKG2D-L transcription. Furthermore, upon therapy with ATRA or VPA, leukaemic blasts become able to trigger lytic granule exocytosis by autologous CD8(+) T and natural killer lymphocytes, as shown by CD107a mobilization assay, followed by leukaemic cell lysis. These findings indicate that ATRA and VPA may contribute to the activation of cytolytic effector lymphocytes in vivo, possibly enhancing their anti-leukaemic effect.

Imatinib is effective for the treatment of chronic myeloid leukemia (CML). However even undetectable BCR-ABL1 by Q-RT-PCR does not equate to eradication of the disease. Digital-PCR (dPCR), able to detect 1 BCR-ABL1 positive cell out of 10(7) , has been recently developed. The ISAV study is a multicentre trial aimed at validating dPCR to predict relapses after imatinib discontinuation in CML patients with undetectable Q-RT-PCR. CML patients under imatinib therapy since more than 2 years and with undetectable PCR for at least 18 months were eligible. Patients were monitored by standard Q-RT-PCR for 36 months. Patients losing molecular remission (two consecutive positive Q-RT-PCR with at least 1 BCR-ABL1/ABL1 value above 0.1%) resumed imatinib. The study enrolled 112 patients, with a median follow-up of 21.6 months. Fifty-two of the 108 evaluable patients (48.1%), relapsed; 73.1% relapsed in the first 9 months but 14 late relapses were observed between 10 and 22 months. Among the 56 not-relapsed patients, 40 (37.0% of total) regained Q-RT-PCR positivity but never lost MMR. dPCR results showed a significant negative predictive value ratio of 1.115 [95% CI: 1.013-1.227]. An inverse relationship between patients age and risk of relapse was evident: 95% of patients45 years relapsed versus 42% in the class ≥45 to65 years and 33% of patients ≥65 years [P(χ(2) ) 0.0001]. Relapse rates ranged between 100% (45 years, dPCR+) and 36% (45 years, dPCR-). Imatinib can be safely discontinued in the setting of continued PCR negativity; age and dPCR results can predict relapse.

Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by an increase in blood platelets and dominated by a predisposition to vascular events. Cutaneous manifestations can complicate its course. itching has been the most common symptom reported; however, the percentage has ranged from 3% to 46%, depending on the survey. Erythromelalgia is found in 6% of cases, and livedo reticularis, minor bleeding, acrocyanosis, and Raynaud's phenomenon are rare manifestations. It is important to recognize and treat these events, because they can affect patients' quality of life and could worsen the prognosis. In addition to skin involvement as a possible sign of ET, the treatment of ET can be associated with cutaneous complications. Hydroxycarbamide, interferon-alfa, and anagrelide can induce different skin lesions. Hydroxycarbamide has been associated with major complications, including painful leg ulcers and actinic keratoses. Minor events include alopecia and hyperpigmentation. Xerosis, pruritus, and photosensitivity are some of the complications reported by patients treated with interferon-alfa. Anagrelide has proved to be associated with fewer dermatologic effects, only detected in single cases. Knowledge of the ET cutaneous manifestations, together with the clinical examination findings, can result in an earlier diagnosis and the start of effective treatment.

BACKGROUND: The incidence of chronic myeloid leukemia (CML) increases with age, but it is unclear how the characteristics of the disease vary with age. In children, where CML is very rare, it presents with more aggressive features, including huge splenomegaly, higher cell count and higher blast cell percentage. PATIENTS AND METHODS: To investigate if after childhood the disease maintains or loses these characteristics of aggressiveness, we analyzed 2784 adult patients, at least 18 years old, registered by GIMEMA CML WP over a 40-year period. RESULTS: Young adults (YAs: 18-29 years old) significantly differed from adults (30-59 years old) and elderly patients (at least 60 years old) particularly for the frequency of splenomegaly (71%, 63% and 55%, P < 0.001), and the greater spleen size (median value: 4.5, 3.0 and 1.0 cm, P < 0.001). According to the EUTOS score, that is age-independent, high-risk patients were more frequent among YAs, than among adult and elderly patients (18%, 9% and 6%, P < 0.001). In tyrosine kinase inhibitors-treated patients, the rates of complete cytogenetic and major molecular response were lower in YAs, and the probability of transformation was higher (16%, 5% and 7%, P = 0.011). CONCLUSIONS: The characteristics of CML or the host response to leukemia differ with age. The knowledge of these differences and of their causes may help to refine the treatment and to improve the outcome. CLINICAL TRIAL NUMBERS: NCT00510926, NCT00514488, NCT00769327, NCT00481052. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

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.

Purpose: The nicotinamide phosphoribosyltransferase (NAMPT) inhibitor, APO866, has been previously shown to have antileukemic activity in preclinical models, but its cytotoxicity in primary leukemia cells is frequently limited. The success of current antileukemic treatments is reduced by the occurrence of multidrug resistance, which, in turn, is mediated by membrane transport proteins, such as P-glycoprotein-1 (Pgp). Here, we evaluated the antileukemic effects of APO866 in combination with Pgp inhibitors and studied the mechanisms underlying the interaction between these two types of agents. Experimental Design: The effects of APO866 with or without Pgp inhibitors were tested on the viability of leukemia cell lines, primary leukemia cells (AML, n = 6; B-CLL, n = 19), and healthy leukocytes. Intracellular nicotinamide adenine dinucleotide (NAD+) and ATP levels, mitochondrial transmembrane potential (ΔΨm), markers of apoptosis and of endoplasmic reticulum (ER) stress were evaluated. Results: The combination of APO866 with Pgp inhibitors resulted in a synergistic cytotoxic effect in leukemia cells, while sparing normal CD34+ progenitor cells and peripheral blood mononuclear cells. Combining Pgp inhibitors with APO866 led to increased intracellular APO866 levels, compounded NAD+ and ATP shortage, and induced ΔΨm dissipation. Notably, APO866, Pgp inhibitors and, to a much higher extent, their combination induced ER stress and ER stress inhibition strongly reduced the activity of these treatments. Conclusions: APO866 and Pgp inhibitors show a strong synergistic cooperation in leukemia cells, including acute myelogenous leukemia (AML) and B-cell chronic lymphocytic leukemia (B-CLL) samples. Further evaluations of the combination of these agents in clinical setting should be considered. Clin Cancer Res; 21(17); 3934–45. ©2015 AACR.

In this study we have analyzed the interaction between in vitro cultured bone marrow stromal cells (BMSC) and NK cells. Ex vivo-isolated NK cells neoexpressed the activation Ag CD69 and released IFN-γ and TNF-α upon binding with BMSC. Production of these proinflammatory cytokines was dependent on ligation of ICAM1 expressed on BMSC and its receptor LFA1 on NK cells. Furthermore, the NKp30, among natural cytotoxicity receptors, appeared to be primarily involved in triggering NK cells upon interaction with BMSC. Unexpectedly, autologous IL-2-activated NK cells killed BMSC. Again, LFA1/ICAM1 interaction plays a key role in NK/BMSC interaction; this interaction is followed by a strong intracellular calcium increase in NK cells. More importantly, NKG2D/MHC-I-related stress-inducible molecule A and/or NKG2D/UL-16 binding protein 3 engagement is responsible for the delivery of a lethal hit. It appears that HLA-I molecules do not protect BMSC from NK cell-mediated injury. Thus, NK cells, activated upon binding with BMSC, may regulate BMSC survival.

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.

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.

BACKGROUND: The INTERIM study (ClinicalTrials.gov NCT 00858806) showed that in elderly (> 65 years) Ph+ CML patients selected for a stable complete cytogenetic response (CCgR) lasting > 2 years, the policy of intermittent imatinib treatment (one month on/one month off) may affect the markers of residual disease (CCgR and major molecular response, MMR or MR3.0), but not the clinical outcomes (overall survival and progression-free survival) (Russo D et al, Blood 2013; 121(26):5138-44). AIMS: To update the results of the INTERIM Study, with a follow up ≥ 5 years. METHODS: After 4 years of follow up, patients continouing INTERIM treatment were monitored with peripheral blood RT-Q-PCR every 3 months according to the ELN-2013 guidelines. RESULTS: At 48thmonth, out of 76 patients enrolled in the INTERIM study, 13 (17%) had lost CCgR and MMR, 14 (18%) had lost MMR only and 50 patients (75%) continued INTERIM. The patients who had lost CCgR and/or MMR resumed imatinib continuously and all of them regained the CCgR and the MMR, within 3 to 12 months. No patient progressed to accelerated or blastic phase, or developed clonal chromosomal abnormalities in Ph+ cells, or BCR-ABL mutations. No patient complained of new or more severe side effects during the months “on”. After a follow up ≥ 5 years, 45/76 (59%) enrolled patients are on INTERIM, with a probability of maintaining intermittent administration of 59% (95% CI: 46-69). No patient lost the CCgR and only 9 additional patients lost the MMR while on intermittent treatment. All these patients resumed continuous imatinib treatment and regained the MMR. Thus, at ≥ 5 years, the probability of maintaing CCgR is 80% (95% CI 68-87) and the probability of maintaining the MMR is 61% (95% CI: 48-71). From start of INTERIM, 6 patients died but no deaths were related to CML progression (3 cases of other non haematological neoplasms, 1 stroke, 1 myocardial infarction, 1 chronic obstructive pulmonary disease).The PFS at ≥ 5 years is 94% (95% CI: 89-100) CONCLUSIONS: In summary, with a follow up ≥ 5 years, intermittent imatinib administration (INTERIM) confirmed to be safe, to produce a reversible increase of residual molecular disease in about one third of patients, but not to affect the long-term outcome. Aknowledgments: This work was supported in part by EuropeanLeukemiaNet (contract LSHC-CT-2004-503216) through the European Treatment and Outcome Study (EUTOS), supported by Novartis Oncology Europe, and COFIN 2009 Disclosures Russo: Celgene: Research Funding; Gilead: Research Funding; Novartis: Consultancy. Martinelli:Novartis: Speakers Bureau; Bristol-Meyers and Squibb: Speakers Bureau; Pfizer: Speakers Bureau. Soverini:Novartis: Consultancy, Honoraria; Bristol-Meyers Squibb: Consultancy, Honoraria; Ariad: Consultancy, Speakers Bureau. Turri:Novartis: Consultancy, Honoraria; Bristol-Meyers Squibb: Consultancy, Honoraria. Castagnetti:Novartis: Consultancy, Honoraria; Bristol-Meyers Squibb: Consultancy, Honoraria. Breccia:novartis: Consultancy; BMS: Consultancy; Celgene: Consultancy. Abruzzese:Novartis: Consultancy. Tiribelli:Novartis: Consultancy, Honoraria; Bristol-Meyers and Squibb: Consultancy, Honoraria. Rosti:Consultant: Consultancy, Speakers Bureau; Bristol-Meiers Squibb: Consultancy, Speakers Bureau; Ariad: Consultancy, Speakers Bureau.

Background. The therapeutic approach in thrombocythemic patients with Philadelphia negative chronic myeloproliferative neoplasms (Ph- MPN), in order to result cost-effective (primum non nocere), is commonly driven by the risk factors considered in the gradually updated guidelines. However, no studies were addressed to evaluate if and how the real-life therapeutic approach changed in the last decades. Objective. To evaluate, in a large series of thrombocythemic patients with Ph- MPN, the impact of clinical and biological characteristics at diagnosis on the therapeutic approach adopted before and after the publication of the Italian guidelines for essential thrombocythemia therapy [1]. Methods. The analysis considered, in the patients of the Registro Italiano Trombocitemie (RIT), the clinical and biological characteristics at diagnosis, and the treatment ongoing after 3, 6, 12, and >12 months from diagnosis (antiplatelet alone [AntiPLT]; cytoreductive alone [CYT]; CYT+AntiPLT). Results. The analyzed patients were 2418, 914 (38%) males and 1504 (62%) females, with a diagnosis (PVSG or WHO criteria) performed before and after 2005 in 51% and 49% of cases, respectively. The rate of ongoing treatment with AntiPLT, CYT, and CYT+AntiPLT increased as follows: at 3rd month 16%, 12%, and 31%; at 12th month 17%, 14%, and 39%; after 12 months 19%, 16%, and 55%, respectively. Patients treated with CYT or CYT+AntiPLT did not significantly differ in their characteristics at diagnosis. The analysis of data at the 3rd month (initial phase) showed that: 1) CYT±AntiPLT treatment, ongoing in 43% of patients, was significantly related, in univariate analysis, to male gender, older age, prior thrombosis, higher thrombocytosis, leukocytosis, higher HCT level, CVRFs, comorbidities, symptoms, splenomegaly, hepatomegaly, and bone marrow fibrosis grade >0 (no relationship with JAK2 V617F mutation, and prior hemorrhage); in multivariate analysis, it was significantly related to age >60 y, age 40-60 y, prior thrombosis, PLT >1000 x109/L, PLT 700-1000 x109/L, symptoms, and comorbidities. 2) patients with standard high risk (age >60 y, and/or prior thrombosis, and/or PLT >1500 x109/L ) were receiving CYT±AntiPLT (59%), AntiPLT (7%), and no treatment (34%). 3) patients with standard low risk were receiving CYT±AntiPLT (22%), AntiPLT (27%), and no treatment (51%). Low risk patients receiving CYT±AntiPLT had age 40-60 y (73%), CVRFs (59%), symptoms (53%), comorbidities (42%), PLT 1000-1500 x109/L (35%), PLT 700-1000 x109/L (42%), JAK2 V617F mutation (30%), WBC >10 x109/L (22%). 4) in patients receiving CYT±AntiPLT, the initial cytoreductive drug and the median age were: hydroxycarbamide (80%, 68 y), anagrelide (6%, 49 y), interferon alpha (9%, 42 y), pipobroman (2%, 72 y), busulfan (3%, 70 y). The AntiPLT drug mostly used was low dose ASA (86-90% of cases, at any age). 5) Patients diagnosed after 2005, compared with those diagnosed before, showed a higher rate of CYT±AntiPLT treatment when at standard high risk ( 64% vs 53 % p Conclusion. The initial (within the 3rd month) therapeutic approach in the thrombocythemic Ph- MPN patients of the RIT was after 2005 relatively compliant with the 2004 Italian guidelines. In fact, the rate of CYT±AntiPLT treatment in patients with standard high risk was higher than before (64% vs 53%, p [1] Barbui T et al. Haematologica 2004; [2] Harrison C et al. NEJM 2005; [3] Gisslinger H et al. NEJM 2013; [4] Passamonti F et al. Blood 2012; [5] Barbui T et al. Blood 2012 *The RIT is a project of the GIMEMA Foundation Disclosures Gugliotta: Shire : Honoraria.

The leukocyte-associated Ig-like receptor-1 (LAIR-1), a surface leukocyte receptor containing two immune receptor tyrosine-based inhibitory motif (ITIM) is expressed on acute myeloid leukemia (AML) blasts isolated from peripheral blood or bone marrow of 17 patients (2 M0, 3 M1, 5 M2, 2 M4 and 5 M5 according to French, American and British classification). Further, we provide evidence thatLAIR-1 engagement inhibits granulocyte-monocyte colony-stimulating factor (GM-CSF)-induced proliferation of AML blasts. Indeed, leukemia cells stimulated with GM-CSF were blocked in the G0/G1 phase of the cell cycle and underwent apoptosis within 4 days after the engagement of LAIR-1. Remarkably, LAIR-1 was functional also in AML blasts which do not express CD33, mainly M4 and M5. Importantly, the LAIR-1 ligation led to a strong inhibition of both GM-CSF receptor-mediated intracellular calcium increases, phosphorylation and activation of Akt1/protein kinase B alpha, a substrate of the phosphatidylinositol-3 kinase. This last inhibitory effect was prevented by a synthetic peptide spanning the ITIM portion of LAIR-1, suggesting the involvement of SHP-1 phosphatase in LAIR-1-mediated inhibitory signal. Altogether, these findings indicate that the engagement of LAIR-1 can down-regulate GM-CSF-mediated survival and proliferation of AML blasts, suggesting an additional therapeutic approach to the treatment of AML patients.

To the editor: Nahimana and coworkers have recently reported that the nicotinamide phosphoribosyltransferase (NAMPT) inhibitor APO866 elicited massive cell death in primary leukemia cells and in numerous leukemia/lymphoma cell lines.[1][1] In particular, in 32 primary leukemias (including 12 B-cell

Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder characterized by the expansion of a leukemic stem cell (LSC) clone, carrying a Philadelphia translocation, able to overcome the non-malignant hematopoietic stem cells. The tyrosine kinase inhibitors (TKIs) imatinib, nilotinib and dasatinib are gold-standard for CML treatment. Each shows an impressive rate of complete cytogenetic response in chronic phase (CP)-CML. However, relapse and treatment failure are major problems with long-term use of TKIs. A polymerase chain reaction (PCR) assay to detect the mRNA expression of BCR-ABL1 represents the main molecular approach to monitoring response to treatment. However, using this analysis it is currently not possible to prospectively identify patients whose disease will relapse due to LSC reappearance. The aim of our study was to investigate whether the mRNA expression analysis of two Hedgehog (Hh) stemness signaling molecules, Smoothened (SMO) and Patched-1 (PTCH1), could predict upcoming molecular relapse. At the time of diagnosis, patients with high Sokal risk (n = 12) showed higher and lower levels of SMO and PTCH1, respectively (p = 0.0132), compared with patients with different Sokal scores (p = 0.0316 for intermediate risk and p = 0.0340 for low risk). These data suggest that Hh signaling was functionally more active in this risk group at the time of diagnosis. Furthermore, the kinetics of Hh signaling activity during the individual medical history correlated with BCR-ABL1 mRNA level and with upcoming molecular relapse. Also, mutation analysis of BCR-ABL1 revealed that activation of Hh signaling precedes molecular relapse by several months, mostly in patients carrying the gatekeeper mutation T315I. Importantly, in vitro data showed a synergistic effect of chemical inhibitors of Hh signaling and TKIs in both wild-type and resistant (T315I) CML cell lines. Collectively our data show that monitoring Hh pathway activity contemporaneously with BCR-ABL1 mRNA level may improve the chance of early detection of patients who will experience a relapse (mainly in the high Sokal risk group), paving the way for an innovative management of this hematologic malignancy.

Abstract 1680 Background. Chronic myeloid leukemia (CML) is characterized by the presence of the BCR-ABL1 hybrid gene. Different types of BCR-ABL1 fusion transcripts can be found, but the most frequent are the e13a2 (b2a2) and the e14a2 (b3a2). In the tyrosine kinase inhibitors (TKIs) era, few data about the prognostic significance of the transcript type in early chronic phase (ECP) CML are available. Three larger studies suggested that the e13a2 transcript may have an adverse prognostic impact in ECP CML patients treated with imatinib (IM): Vega-Ruiz et al. (251 patients, ASH 2007) reported inferior molecular responses; Lucas et al. (71 patients, Haematologica 2009) reported lower cytogenetic response rates and lower event-free survival (EFS); the GIMEMA CML WP (493 patients, EHA 2011) reported a slower time to major molecular response (MMR) with inferior EFS and progression-free survival (PFS). To our knowledge this is the first evaluation of the prognostic influence of the BCR-ABL1 transcript type on the responses and the outcome of ECP CML treated frontline with nilotinib (NIL). Methods. The CML Italian Registry of Nilotinib includes 215 patients treated with NIL-based regimens. The patients were enrolled within 2 multicenter phase II studies conducted by the GIMEMA CML WP (ClinicalTrials.gov. NCT00481052 and NCT00769327) or treated at the “S. Orsola-Malpighi” University Hospital (Bologna, Italy), with NIL 300 mg BID or 400 mg BID as initial treatment. All the registered patients were analyzed. Patients expressing rare transcripts and patients with both b2a2 and b3a2 transcripts were excluded: 201 out of 215 patients were evaluable, 81 (40%) with e13a2 transcript and 120 (60%) with e14a2 transcript. Differences between groups were tested using χ2 test, Fisher exact test or t-test, as appropriate. Response monitoring: conventional cytogenetic examination (bone marrow) and QPCR (peripheral blood). Definitions: MMR: BCR-ABLIS ratio Results. The baseline characteristics of the 2 groups were comparable (no significant differences in age, Sokal/Hasford/EUTOS score distribution, clonal chromosomal abnormalities in Ph+ cells, NIL dose), except for the percentage of basophils in the peripheral blood, higher in patients with e14a2 transcript (3.4% vs 2.3%, p=0.01). The median observation was 29 months (range 18–47); 92% of the patients had at least 2 year observation. The CCgR and MMR rates at 12 months were comparable in the 2 groups. The time to MMR was longer for patients with e13a2 transcript (6 months vs 3 months, p=0.04), but the overall CCgR rates (93.8 vs 91.7, p=0.79) and the overall MMR rates (85.1 vs 90.0, p=0.38) were not significantly different in patients with e13a2 or e14a2 transcript, respectively. The probability of Overall Survival (OS), Progression-Free Survival (PFS) and Failure-Free Survival (FFS) were comparable: 91.4% vs 95.8% (p=0.61), 90.7% vs 95.0% (p=0.51), and 90.7% vs 88.7% (p=0.40) in patients with e13a2 and e14a2 transcript, respectively. Conclusions. In our experience, based on 201 early CP CML patients treated frontline with NIL with a minimum follow-up of 18 months, the BCR-ABL transcript type did not show any relevant prognostic impact. The time to MMR was longer in patients with e13a2 transcript, but no response and outcome differences have been observed so far. The number of observed events was low and a longer observation is required. Acknowledgments. European LeukemiaNet, COFIN, Bologna University, BolognAIL Disclosures: Castagnetti: Novartis Pharma: Consultancy, Honoraria, Speakers Bureau; Bristol Myers Squibb: Consultancy, Honoraria, Speakers Bureau. Gugliotta:Novartis: Consultancy, Honoraria; Bristol-Myers-Squibb: Consultancy, Honoraria. Breccia:Bristol Myers Squibb: Consultancy; Novartis: Consultancy. Cavazzini:Novartis Pharma: Honoraria; Bristol Myers Squibb: Honoraria. Turri:Novartis: Consultancy, Novartis Other; Bristol Myers Squibb: Bristol Myers Squibb, Bristol Myers Squibb Other, Consultancy. Soverini:Novartis: Consultancy; Bristol-Myers Squibb: Consultancy; ARIAD: Consultancy. Saglio:Novartis: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau; Pfizer: Consultancy. Martinelli:Novartis: Consultancy, Honoraria, Speakers Bureau; Bristol-Myers-Squibb: Consultancy, Honoraria, Speakers Bureau. Baccarani:ARIAD, Novartis, Bristol Myers-Squibb, and Pfizer: Consultancy, Honoraria, Speakers Bureau. Rosti:Novartis Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Speakers Bureau; Pfizer: Speakers Bureau.

Background: Acute Myeloid Leukemia (AML) is an incurable disease characterized by a highly unstable genome, resulting in large-scale changes at diagnosis, as well as further evolution contributing to disease progression. However, the mechanisms whereby tumor cells adapt to genomic instability are largely unknown, but recent observations have correlated these abnormalities with dysfunctional DNA damage repair (DDR) machinery. SIRT6 is an important regulator of cellular stress response and genomic integrity. Here we investigated the role of this NAD+ -dependent deacetylase in regulating ongoing DNA damage observed in AML patients. Methods: SIRT6 mRNA level was determined by RT-qPCR in AML patients (n=100) diagnosed at the Hematology Department of University of Genoa (Italy), compared with normal bone marrow derived CD34+ cells (n=5). Correlation studies with clinical and molecular characteristics of these patients were also performed. A panel of different AML cell lines and primary cells, both sensitive and resistant to conventional and novel anti-AML therapies, was used in the study. The anti-leukemic effect of DNA-damaging agents (DDAs) including idarubicin, Ara-C and fludarabine was evaluated in presence of SIRT6 depletion/inhibition by CTG assay and Annexin-V/propidium iodide staining. Mechanistic studies were performed with Western-blotting, lentivirus-mediated shRNAs and immunofluorescence assay. Analysis of DNA DSB repair was done using chromosomally integrated reporter constructs, followed by cytometer analysis. Results: AML patients were grouped into lower and higher SIRT6 expressers according to its median mRNA level. Patients with lower expression had a higher incidence of FLT3-ITD (p=0.034, Wilcoxon signed rank test). No significant association was observed with respect to mutations of NPM1, nor with WT1 and BAALC expression. SIRT6 expression correlated also with adverse clinical outcome in term of event free and overall survival (p=0.035 and p=0.025, respectively; unpaired t test). Based on these data, we evaluated SIRT6 role in biology of AML. We found higher SIRT6 protein level in AML cell lines carrying FLT3-ITD mutation (MOLM-14 and MV 4-11) compared to cell lines harboring other mutations (OCI-AML3, THP-1, KG, NB4, HL60, Nomo1 and U937). Targeting SIRT6 by specific shRNAs weakly reduced AML cell survival compared with control-scrambled cells, by impairing DNA repair efficiency. Indeed, a restricted effect of SIRT6 impairment on DNA damage proteins (H2AX, RAD51, 53BP1, RPA32) was measured. We next examined the therapeutic relevance of SIRT6 inhibition in AML by testing effects of its depletion in combination with genotoxic agents. Remarkably, SIRT6 depletion conferred increased sensitivity of AML cells to idarubicin, Ara-C and Fludarabine. Overall, enhancing genotoxic stress while concomitantly blocking DNA double-strand breaks (DSBs) repair response, may represents an innovative strategy to increase chemosensitivity of AML cells. Further mechanistic studies revealed that SIRT6 acts as a genome guardian in leukemia cells by binding DNA damage sites and activating DNA-PKcs and CtIP by deacetylation, which in turn promotes DNA repair. Conclusion: Genomic instability is present in all hematologic malignancies including AML. Strategies aimed to shift the balance towards high DNA damage and reduced DNA repair by SIRT6 inhibition can decrease AML growth and may benefit patients with otherwise unfavorable outcomes. Disclosures No relevant conflicts of interest to declare.

Background. In patients with Ph-negative chronic myeloproliferative neoplasm (MPN) the molecular pattern, beside other characteristics at diagnosis, has been related to the disease prognosis. Aim. To compare clinical and biological features at diagnosis and during the follow-up in gender/age-matched MPN patients showing different molecular pattern. Material and methods. The Registro Italiano Trombocitemie (RIT) is a web-based registry that includes thrombocythemic MPN patients diagnosed according to PVSG or WHO criteria, registered after 2005, and then prospectically followed. The JAK2 V617F mutation (JAK2+) was reported in 941 (58.4%) out of 1610 tested patients. On the basis of subsequent tests, performed in part of the JAK2 WT (JAK2-) subjects, 103 patients were JAK2-/CALR+ (CALR+), 14 patients were JAK2-/CALR-/MPL+ (MPL+), and 46 were JAK2-/CALR-/MPL- (3NEG). The 103 CALR+ patients were compared with 309 (103 x 3) JAK2+ patients matched for gender, age, and revised diagnosis (WHO 2008 criteria). A similar comparison was done between 46 3NEG patients and other 138 (46 x 3) JAK2+ matched patients. Results. CALR+ and matched JAK2+ patients had, as expected, the same gender distribution (males 41%), the same median age (51 years), and no significant difference (p 0.42) in the WHO diagnosis distribution. CALR+ patients, as compared with JAK2+ patients, showed at diagnosis: higher median platelet (PLT) count (839 vs 718 x109/L, p CARL+ and JAK2+ patients had the same rate of antiplatelet and cytoreductive treatment (96% vs 96%, and 86% vs 84%, respectively). During the follow-up the incidence of thrombotic and hemorrhagic events was not significantly different (1.3 vs 1.1/100 pt-years, and 1.0 vs 0.6/100 pt-years, respectively). Moreover, no significant difference was observed in the incidence of evolution to overt primary myelofibrosis (PMF, 0.76 vs 0.61/100 pt-years), polycythemia vera (PV, 0 vs 0.24/100 pt-years), and AL/MDS (0.08 vs 0.10/100 pt-years). Finally, the same overall survival was found after 5, 10. 15, and 20 years (99, 97, 94, 93%, respectively). 3NEG patients, as compared with JAK2+ matched patients, showed at diagnosis: lower median WBC count (7.9 vs 10.9 x 109/L, p 0.03); lower Hb and/or HCT level (p 0.006); lower rate of splenomegaly (7% vs 28%, p 0.003); lower rate of symptoms (35% vs 51%, p 0.049). No significant difference was found in: median PLT count (700 vs 720 x 109/L, p 0.61); PrTh (7% vs 16%, p 0.11); prior hemorrhage (4.7% vs 7.5%, p 0.52); high/intermediate thrombotic risk (IPSET, 36 vs 48%, p 0.37). Moreover, no significant difference was observed during the follow-up in: antiplatelet and cytoreductive treatment; thrombosis and hemorrhage rate; PMF, PV, and AL/MDS evolution; overall survival. Conclusion. CALR+ patients, as compared with JAK2+ matched patients, although showed a lower thrombotic risk (lower WBC and HCT levels, lower PrTh rate), received the same antiplatelet and cytoreductive treatment, had the same incidence of adverse events during the follow-up (vascular complications and disease evolution/transformation), and had the same overall survival. 3NEG patients, as compared with JAK2+ matched patients, showed results similar to those observed by comparing CALR+ and JAK2+ matched patients. To better define the role of the precise definition of molecular pattern in Ph-MPN patients, new prospective controlled studies seem necessary. Disclosures De Stefano: Janssen Cilag: Research Funding; Roche: Research Funding; Novartis: Research Funding, Speakers Bureau; Amgen: Speakers Bureau; Bruno Farmaceutici: Research Funding; Celgene: Speakers Bureau; GlaxoSmithKline: Speakers Bureau; Shire: Speakers Bureau. Passamonti:Novartis: Consultancy, Honoraria, Speakers Bureau.

Introduction: Very little is known about health-related quality of life (HRQOL) of patients diagnosed with primary Immune Thrombocytopenia (pITP). Also, the paucity of available data mainly stems from patients enrolled in randomized controlled trials thus limiting generalizability of findings to patients routinely seen in real world practice. Aim: The main objective of this study is to compare HRQOL of pITP patients with that of their peers from the general population and to investigate whether HRQOL differences exist among those classified as (Rodeghiero et al, Blood. 2009 Mar 12;113(11):2386-93): newly diagnosed, persistent and chronic pITP patients. Methods: Adult patients with pITP were consecutively enrolled, regardless of therapy, in 25 centers. All patients were invited by their treating physicians in the hospital. Consenting patients were requested to complete a battery of patient-reported outcome (PRO) questionnaires. The primary HRQOL outcome measure was the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). It consists of 36 items covering eight generic health status/QoL domains: physical functioning (PF), role limitations due to physical health (RP), bodily pain (BP), general health perceptions (GH), vitality (VT), social functioning (SF), role limitations due to emotional problems (RE), and mental health (MH). To minimize possible bias in comparisons of pITP patients HRQOL outcomes to general population norms, a propensity score matching approach plus further regression adjustment was adopted to select the best possible case-control pairs. The group of potential controls was a representative sample of 1997 adults without the disease from a previous study which provided SF-36 population norms. Controls from these data were matched to pITP patients by an optimal nearest-neighbour matching algorithm based on age, sex, education, and geographic area. Multiple linear regression analyses were performed on the matched dataset to compute adjusted mean differences (α=0.05), using selected a priori key HRQOL confounders as covariates: age, sex, education, geographic area, and marital status. Effect sizes were computed and clinical significance of mean scores SF-36 differences was also estimated. Results: Out of 424 patients invited to participate, 420 returned the questionnaires (99% compliance). At study participation, mean age of patients was 54 years (range 18-89) with the majority being women (N=264, 64%). The mean platelet count at diagnosis was 27.6 x109/L and the mean platelet count at last medical visit, before the HRQOL assessment, was 119 x109/L. Two-hundred twenty patients (50%) had at least 1 comorbidity. At the time of HRQOL assessment there were 82%, 64% and 44% of patients receiving active treatments, respectively in the newly diagnosed, persistent and chronic pITP group. Splenectomy was performed in 8% and 22% of the persistent and chronic pITP patients, respectively. No statistically significant differences existed among the three disease groups with regard to age, gender and presence of comorbidity. When compared with their peers in the general population, worse statistically significant outcomes (P Conclusions: Persistent pITP patients are those experiencing the most important limitations in both physical and mental HRQOL domains with respect to their peers from the general population. This information can help physicians to pay special attention to this patient group in their daily clinical practice. Disclosures Gaidano: Celgene: Research Funding; MorphoSys; Roche; Novartis; GlaxoSmithKline; Amgen; Janssen; Karyopharm: Honoraria, Other: Advisory boards. Rodeghiero:Celgene Corporation: Honoraria, Research Funding.

Introduction. A substantial proportion of patients (pts) affected by Chronic Myeloid Leukemia (CML) achieve complete negativity in Q-RT-PCR. In this situation, as already demonstrated in other STOP trials, it is possible to safely discontinue imatinib treatment but it is still not clear how to discriminate subjects who will relapse. In fact even undetectable BCR-ABL may not equate to eradication of the disease because of the sensitivity of Q-RT-PCR. A new diagnostic method, the digital-PCR (dPCR), able to detect 1 BCR-ABL+ cell out of 107 cells, has been developed. Therefore, dPCR by assessing the presence of minimal residual disease with higher sensitivity, could potentially identify pts in whom CML has been eradicated. Aims. The ISAV study is aimed at validating the capability of dPCR to predict relapses after imatinib discontinuation in CML pts with negative Q-RT-PCR results and to evaluate relapse rate and timing of recurrence, survival and the impact of imatinib treatment on Quality of Life (QoL). Methods. This study involves 15 sites, 10 in Italy and 1 in each of the following countries: Germany, Spain, The Netherlands, Canada and Israel. CML pts (Chronic or Accelerated Phase) under imatinib therapy since more than 2 years and in complete molecular remission (CMR) were eligible. Patients had to be in CMR for at least 18 months (mts), with a minimum of 3 Q-RT-PCR performed at their own sites. After signing the informed consent, blood samples were obtained for dPCR and the pts discontinued imatinib therapy. Standard Q-RT-PCR is performed monthly (mts 1-6) and then bimonthly for 36 mts to assess the maintenance of the molecular remission. The loss of molecular remission is defined as two consecutive positive Q-RT-PCR tests with at least one BCR-ABL/ABL value above 0.1%. Patients losing molecular remission resume imatinib treatment at the same dosage used before interruption. Patients' QoL during imatinib discontinuation/resumption is evaluated through the EORTC QLQ-C30 questionnaire. Results. The study enrolled 112 pts with a median follow-up (FUP) time of 28.0 mts [95% CI: 25.5-30.1]. The 59.3% of pts were male and 37.0% were aged 65 or older; median duration of imatinib treatment was 103.1 mts with median duration of CMR of 25.7 mts before imatinib discontinuation. The cumulative probability of survival is 97.8% [95% CI: 91.4-99.5]. dPCR results showed that 23.1% of pts were positive and 75.9% negative, with a significant Negative Predictive Value ratio (dPCR/Q-RT-PCR) of 1.112 [95% CI: 1.009-1.225]. At 24 mts from imatinib discontinuation, 53 pts (49.1%, 95% CI: 39.3-58.9) of the 108 eligible pts relapsed and resumed imatinib; 73.6% of them relapsed in the first 9 mts and the last relapse occurred 21.8 mts after imatinib discontinuation. A loss of CCyR occurred in 13 pts (34.2% of those tested): 10/13 CCyR losses were recovered, the remaining 3 were not assessed for response. No case of CML progression or resistance to imatinib was observed. After the resumption of imatinib the median time to MMR/CMR was 1.9 [95% CI: 1.2-2.4] mts. Of the 55 not-relapsed pts, 42 (38.9% of the total) regained Q-RT-PCR positivity but never lost MMR. The median time to Q-RT-PCR positivity was 2.9 mts [95% CI: 2.0-3.1] in the relapsed pts and 4.5 mts [95% CI: 2.9-6.9] in pts who developed only PCR positivity. No significant correlation between relapse and previous duration of imatinib treatment, use of interferon, time to CCyR, Sokal score or duration of CMR was identified, while an inverse relationship between pts age and risk of relapse is evident. Moreover, age and dPCR results together can predict the risk of relapse: pts with less than 45 years and with a positive dPCR had the highest risk of relapse (100%) as opposed to pts ≥ 45 years and with negative dPCR (36.1%). The analysis of QoL evidenced a statistically significant improvement in the general well-being and symptoms scales at 1 month after imatinib discontinuation and in particular nausea, diarrhea and fatigue (p Conclusions. At 45 mts from the beginning of the study, with a median FUP of 28.0 mts, 49.1% of pts relapsed; the majority of relapses developed in the first 9 mts after imatinib discontinuation. Age < 45 years and dPCR positivity are significantly associated with relapses. QoL analysis showed a significant decrease in symptoms after imatinib discontinuation. Funded by Regione Lombardia. Disclosures Abruzzese: BMS, Novartis, Pfizer, Ariad: Consultancy. Assouline:BMS: Consultancy; Pfizer: Consultancy; Novartis: Consultancy. D'Emilio:Celgene: Research Funding. Dong-Wook:ll-Yang: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau.

Background. Nilotinib 300 mg BID was approved as frontline treatment in chronic phase chronic myeloid leukemia (CP-CML) patients and allowed to reach deep molecular responses in a shorter median time with reduction of progression rate. Nilotinib is associated to a specific safety profile, with metabolic side effect as the most common events and increased probability of cardiovascular disorders. Aim. Aim of our study is to prospectively assess metabolic changes and cardiovascular safety during treatment with nilotinib, in a single arm multicentric Italian GIMEMA trial (0811), testing the drug as frontline treatment with the primary endpoint to obtain MR4 at 24 months. All metabolic changes were classified according to CTC grade. Lipidic changes were assessed according to American Association of Clinical endocrinologist criteria of 2012 and glucose abnormalities according to American diabetologist association (ADA). Results. One hundred and thirty patients were enrolled in 33 different centers: median age 50.5 years (range 18-85), 64.6% male. Mean body mass index (BMI) was 25.3, with 40% of patients being overweight/obese according to WHO classification. At last contact, 100 patients were still in treatment, the majority with full dose (86%). According to ADA criteria 47%, 10%, 4.6% and 6% of patients experienced grade 1 (101-125 mg/dl), grade 2 (126-150 mg/dl), grade 3 (151-200 mg/dl) and grade 4 (>200 mg/dl), increased fasting glucose, respectively. As compared to baseline, a significant variation was observed after 1 year (p8), respectively according to ADA criteria. AACE criteria identified a significant reduction of triglycerides (p Conclusions. Prospective monitoring of metabolic safety during frontline treatment with nilotinib 300 mg BID showed consistent and specific profile with increased glycaemia and cholesterol level, mostly of grade 1-2. Possible occurrences of cardiovascular side effects impose identification of patients at risk at baseline and a correct monitoring during follow-up. Disclosures Castagnetti: Novartis: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; ARIAD: Consultancy, Honoraria. Gugliotta:BMS: Honoraria; Novartis: Honoraria. Tiribelli:Novartis Farma: Consultancy, Speakers Bureau; Bristol Myers Squibb: Consultancy, Speakers Bureau; Ariad Pharmaceuticals: Consultancy, Speakers Bureau. Saglio:Pfizer: Consultancy, Honoraria; ARIAD: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Novartis Pharmaceutical Corporation: Consultancy, Honoraria. Baccarani:PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; NOVARTIS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ARIAD Pharmaceuticals, Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Rosti:Novartis: Honoraria, Research Funding, Speakers Bureau; Bristol Myers Squibb: Honoraria, Research Funding, Speakers Bureau.

Imatinib mesylate is a first line treatment of Chronic Myelogenous Leukemia and of a rare form of gastrointestinal stromal cancer, where the response to the drug is also linked to the immune system activation with production of antineoplastic cytokines. In this study, forty patients in the chronic phase of disease, treated with imatinib mesylate, were analyzed. Bone marrow aspirates were drawn at diagnosis, after 3, 6, 12, 18 months for haematological, cytofluorimetric, cytogenetic, biomolecular evaluation and cytokine measurement. Responder and non responder patients were defined according to the European LeukemiaNet recommendations. In responder patients (n = 32), the percentage of bone marrow CD20(+)CD5(+)sIgM(+) lymphocytes, and the plasma levels of IgM, were significantly higher, at 3 months and up to 9 months, than in non responders. These IgM reacted with O-linked sugars expressed by leukemic cells and could induce tumor cell apoptosis. In responder patients the stromal-derived factor-1 and the B-lymphocyte-activating factor of the tumor necrosis factor family significantly raised in the bone marrow after imatinib administration, together with the bone morphogenetic proteins-2 and -7. All patients with high number of CD20(+)CD5(+)sIgM(+) cells and high stromal-derived factor-1 and B lymphocyte activating factor levels, underwent complete cytogenetic and/or molecular remission by 12 months. We propose that CD20(+)CD5(+)sIgM(+) lymphocytes producing anti-carbohydrate antibodies with anti-tumor activity, might contribute to the response to imatinib treatment. As in multivariate analysis bone marrow CD20(+)CD5(+)sIgM(+) cells and stromal-derived factor-1 and B-lymphocyte-activating factor levels were significantly related to cytogenetical and molecular changes, they might contribute to the definition of the pharmacological response.

Abstract 453 Background: Imatinib (IM) 400 mg daily is the standard treatment for Ph+ Chronic Myeloid Leukemia (CML) in early Chronic Phase (ECP). Nilotinib (NIL) is a 2nd generation tyrosine kinase inhibitor (TKI) with superior efficacy to IM (phase 3 ENESTnd trial). NIL has been approved for the frontline treatment of CML in many countries. The treatment with more than one TKI, according to the principles of cancer polychemotherapy, may improve the response rates and may decrease the frequency of drug-resistance. The combination of different TKIs is potentially toxic, difficult to be explored in the ECP setting. The sequential administration of IM and NIL is worth to be investigated because a significant proportion of CML patients treated with a single TKI as monotherapy develops primary or secondary resistance. Aims: To evaluate the response (either cytogenetic and molecular) and the outcome of ECP Ph+ CML patients treated with the sequential administration of NIL and IM. Methods: A phase 2 study was conducted by the GIMEMA CML WP (ClinicalTrials.gov. NCT00769327). NIL was administered first because it has a more rapid therapeutic effect. Schedule: NIL 400 mg twice daily for 3 months; IM 400 mg daily for the next 3 months; then, NIL and IM turning every 3 months, for a total duration of 24 months (study core). The 3-month rotation schedule was respected, irrespectively of temporary discontinuations. The primary end-point was the Complete Cytogenetic Response (CCgR) rate at 12 months. If the conventional cytogenetic analysis resulted not evaluable, a FISH analysis was performed. If one of the 2 drugs was permanently discontinued for adverse event (AE), the patient remained in study, continuing the treatment with the other drug (except for cardiac AEs). Definitions: Major Molecular Response (MMR): BCR-ABL/ABL ratio < 0,1%IS; failure: according to 2009 ELN recommendations; event: failure, permanent discontinuation of both drug for any reason, patient refusal. All the analysis were performed according to the ITT principle. Results: 123 patients have been enrolled in 38 italian hematologic Centers; median age 56 years (range 18–84); 33% low, 45% intermediate and 22% high Sokal score; median follow-up 21 months (at least 12 months observation, 24 months by November 2011). The cumulative CCgR rate by 12 months was 87%; CCgR at each milestone: 68% at 3 months, 73% at 6 months, 67% at 12 months (primary efficacy variable). The cumulative MMR rate by 12 months was 82%, while the rates of MMR at 3, 6 and 12 months were 59%, 62% and 60%, respectively. The discrepancies between cumulative response rates and response at each timepoint were mainly due to the number of patients not evaluable at each timepoint (10% of cytogenetic analysis not evaluable at 12 months) and to protocol discontinuation in stable CCgR and/or MMR. The incidence of hematologic AEs was low. Non-hematologic AEs or lab abnormalities grade > 2 observed in >5 % of patients were as follows: NIL - skin rash, pruritus, bilirubin increase, transaminase increase, lipase increase; IM - fluid retention, periorbital edema. AEs were manageable with appropriate dose adaptations. Four patients (3%) showed a prolongation of the QTcF above 450 msec (none above 500 msec). At the end of the first 12 months, 95 patients (77%) remained on study: 6 and 3 on NIL and IM monotherapy, respectively, 86 on sequential treatment with both drugs; 15% of patients permanently reduced the NIL dose to 400 mg daily and 9% of patients permanently reduced the IM dose to 300 mg daily. During the first year, 28 patients (23%) experienced an event: 10 treatment failure (8%); 2 death in CP (2%); 16 refusal, protocol violation or AE (13%). Six out of the 10 patients who failed the treatment progressed to advanced phase (3 patients: detection of a T315I mutation). Conclusions: The cumulative response rates achieved with a sequential administration of NIL and IM seem to be superior to the historical data of IM alone. The response rates at each timepoint, lower than expected, were probably due to the high number of not evaluable patients and to the number of patients not continuing the study despite a stable CCgR/MMR. However, if compared to the excellent results of 2nd generation TKI as monotherapy in ECP CML (single and randomized trials), the present analysis do not support an alternating schedule of NIL and IM as frontline treatment of ECP CML. Acknowledgments: European LeukemiaNet, COFIN, Bologna University, BolognAIL Disclosures: Castagnetti: Novartis Pharma: Honoraria; Bristol-Myers Squibb: Honoraria. Rosti:Novartis: Consultancy; Bristol Myers Squibb: Consultancy; Novartis: Research Funding; Novartis: Honoraria; Bristol Myers Squibb: Honoraria. Soverini:Novartis: Consultancy; ARIAD: Consultancy; Bristol-Myers Squibb: Consultancy. Martinelli:Bristol-Myers Squibb: Consultancy; Novartis: Consultancy, Research Funding.

Treatment of Hodgkin’s lymphoma (HL) is perceived to be relatively straightforward. Consequently, patients are not usually referred to hemato-oncologically specialized centres and are treated locally instead. Comprehensive findings beyond prospective controlled trials are therefore lacking. Clinical data of 209 patients who had received a HL diagnosis were collected. A total of 7 patients received radiotherapy (RT) alone (3%), 75 (35%) were treated with a combination of chemotherapy (CT) and RT and 127 patients received CT alone [mainly doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD)]. Complete response (CR) following first-line treatment was achieved in 178 patients (85%) and in 195 (93%) after salvage treatment. Favorable disease (p=0.000359), limited-stage disease (p=0.0003), involvement of lymph nodes above the diaphragm (p=0.05) and absence of mediastinal bulky tumor involvement positively affected the CR rate following first-line treatment. Out of the 195 patients that achieved CR, 31 relapsed. Male gender (p=0.043) and age over 45 years (p=0.047) were significantly associated with an increased incidence of relapse. Age at diagnosis was the key factor affecting long-term outcome. The event-free survival (EFS) projected at 120 months was 80 and 57% for patients younger and older than 45 years, respectively (p=0.022). The overall survival (OS) projected at 120 months was 92 and 38% for patients younger and older than 45 years, respectively (p=0.00561). A second neoplasia was diagnosed in 8 patients. The development of a tumor in 4 cases (breast, lung and thyroid cancer) was likely RT-related. Only 1 patient not receiving RT developed acute myeloid leukemia. The EFS and OS of the 141 early-stage patients treated with CT + RT (n=62) or with CT alone (n=79) were not statistically different.

Aberrant histone deacetylase (HDAC) activity is frequent in human leukemias. However, while classical, NAD(+)-independent HDACs are an established therapeutic target, the relevance of NAD(+)-dependent HDACs (sirtuins) in leukemia treatment remains unclear. Here, we assessed the antileukemic activity of sirtuin inhibitors and of the NAD(+)-lowering drug FK866, alone and in combination with traditional HDAC inhibitors. Primary leukemia cells, leukemia cell lines, healthy leukocytes and hematopoietic progenitors were treated with sirtuin inhibitors (sirtinol, cambinol, EX527) and with FK866, with or without addition of the HDAC inhibitors valproic acid, sodium butyrate, and vorinostat. Cell death was quantified by propidium iodide cell staining and subsequent flow-cytometry. Apoptosis induction was monitored by cell staining with FITC-Annexin-V/propidium iodide or with TMRE followed by flow-cytometric analysis, and by measuring caspase3/7 activity. Intracellular Bax was detected by flow-cytometry and western blotting. Cellular NAD(+) levels were measured by enzymatic cycling assays. Bax was overexpressed by retroviral transduction. Bax and SIRT1 were silenced by RNA-interference. Sirtuin inhibitors and FK866 synergistically enhanced HDAC inhibitor activity in leukemia cells, but not in healthy leukocytes and hematopoietic progenitors. In leukemia cells, HDAC inhibitors were found to induce upregulation of Bax, a pro-apoptotic Bcl2 family-member whose translocation to mitochondria is normally prevented by SIRT1. As a result, leukemia cells become sensitized to sirtuin inhibitor-induced apoptosis. In conclusion, NAD(+)-independent HDACs and sirtuins cooperate in leukemia cells to avoid apoptosis. Combining sirtuin with HDAC inhibitors results in synergistic antileukemic activity that could be therapeutically exploited.

Eight patients affected by non-small-cell lung cancer were treated with intralesional and systemic recombinant IL-2 (rIL-2) injection with the aim of activating both tumour-infiltrating lymphocytes and circulating cytotoxic or killer cells. The schedule of treatment was as follows: a daily fine-needle transparietal intralesional rIL-2 injection (1 x 10(5) Cetus units) from day 1 to day 5 and systemic rIL-2 infusion (1 x 10(5) Cetus units kg-1 day-1) from day 6 to day 10. One to four cycles of treatment were received by each patient. Clinical and immunological evaluations were performed (a) before treatment, (b) following the intralesional rIL-2 administration, (c) 1 h after the beginning of rIL-2 infusion and (d) at the end of the systemic rIL-2 infusion. No complete remission was achieved, two patients showed a partial remission, three resulted in stable disease and three patients progressed. Natural killer and lymphokine-activated killer cell activity dramatically decreased 1 h after the beginning of rIL-2 infusion and increased at the end of treatment. A progressive increase of circulating CD8+ and HLA class II+ T cells as well as of CD8+ T cell clones, most of which displayed NK activity, was recorded following rIL-2 infusion. Present data indicate that (a) the local administration of rIL-2 coupled with systemic rIL-2 infusion may be suggested as an alternative approach for the immunotherapy of lung cancer, (b) rIL-2 induces different immunological modifications according to the route and the time of its administration and (c) rIL-2 administration increases the amount of circulating immune cells with potential antitumour activity.

Myelofibrosis with myeloid metaplasia (MMM) is a clonal disorder involving disregulation of angiogenesis and immunomodulatory mechanisms. Thalidomide (Thal) retains antiangiogenic, immunomodulatory and cytokine regulatory properties and recently it has been used successfully in multiple myeloma. Here, we report our experience in 10 MMM patients treated with Thal. Patients with agnogenic MMM treated in an early phase of the disease obtained significant benefits from the therapy and remain transfusion-free. In contrast, all secondary MMM failed to respond. These preliminary findings confirm that Thal plays a role in MMM therapy, although the efficacy in the different phases of the disease must be further evaluated.

Abstract 1973 Background. Hematological and extra-hematological adverse events associated to Hydroxyurea (HU) treatment in patients with chronic myeloproliferative neoplasms (MPN) are object of particular interest in the Ph-negative MPN since they can significantly limit the HU use. Objective. To evaluate the extra-hematological adverse events associated to HU treayment in a large cohort of Essential Thrombocythemia (ET) patients. Material and Methods. One thousand and seventy-five out of the 2005 ET patients registered in the RIT were treated with HU and are the object of this report. The patients, 641 females (59.6%) and 434 males (40.4%), diagnosed according to the PVSG or WHO criteria in 54 hematological centers of the RIT, started treatment with HU as first (92%) or second (8%) line, at median age of 65 years.The mean duration of HU treatment was 3.3 years. The HU treatment was withdrawn in 221 (20.5%) patients after a mean of 3.0 years.The administered dose of HU was 0.25–3.0 g/day (median 1), and a mean cumulative dose was 1113 g. The extra-hematological adverse events (EHAEs) observed during the HU treatment were distinguished in HU related AEs (HU-EHAEs), ET related AEs (ET-EHAEs) and HU or ET unrelated AEs (U-EHAEs).Results. During the HU treatment (3587 pt-y) 378 EHAEs were reported in 207 (19.3%) patients, being the HU-EHAEs 244 (6.8/100 pt-y) in 170 (15.8%) patients. In detail, the HU-EHAEs were: dermatological in 108 (48.3%) cases (38 hyperpigmentation, 26 leg ulcers, 22 maculo-papular rash, 10 lichenoid eruptions, 5 skin cancer, 4 alopecia); gastro-intestinal in 80 (32.8%) cases (37 nausea/vomiting, 30 diarrhea, 13 gastro-intestinal intolerance); systemic in 35 (14.3%) cases (28 fever, 7 fatigue); neurological in 19 (7.8%) cases (headache); miscellanea in 2 (0.8%) cases. Conclusion. This preliminary analysis in 1075 ET patients of the Registro Italiano Trombocitemia (RIT) treated with HU shows that the extra-hematological adverse events referred to the HU (HU-EHAEs) occurred with not negligible rate (6.8/100 pt-y) and need to be object of attention in the management of ET patients. Disclosures: No relevant conflicts of interest to declare.

Before the introduction of imatinib, interferon alpha-based regimens were the gold standard for treatment of early chronic phase chronic myeloid leukemia patients. The combination of IFN-alpha with imatinib is currently being investigated in at least two large clinical trials, the German CML Study IV and the French SPIRIT trial. We reviewed the cytogenetic and molecular responses of 76 early chronic phase chronic myeloid leukemia patients who were treated with imatinib and interferon-alpha and of 419 early chronic phase chronic myeloid leukemia patients treated with imatinib alone front-line. The complete cytogenetic response rate was higher in the IM+IFN-alpha group than in the imatinib group at six months (60% vs. 42%; P=0.003), but not at 48 months (88% vs. 88%). The durability of the complete cytogenetic response was similar in the two groups with 94% and 91% of complete cytogenetic responders in continuous complete cytogenetic response at 48 months (P=0.56). The major molecular response rate was higher in the IM+IFN-alpha group at six months (58% vs. 34%; P=0.0001) and 12 months (67% vs. 47%; P=0.001) but not later on (65% vs. 57% at 48 months; P=0.25). Overall and progression free survival were comparable in the two groups; a significant trend to a better event free survival was observed in patients treated with PegIFNalpha (91% vs. 78%; P=0.02). These data suggest that the response to the combination treatment is more rapid. It is not yet known how much a rapid reduction will influence the longer-term overall and progression free survival, and the cure rate.

Acquired resistance to imatinib in the advanced phase of chronic myeloid leukemia (CML) has been associated with mutations in the kinase domain (KD) of BCR-ABL. On the contrary, the prognostic implication of KD mutations in early chronic phase (CP) patients at diagnosis before imatinib-based therapy has not yet been established. We have reviewed the status of mutations in 43 patients with early CP-CML on the samples collected at diagnosis. Mutations were identified by direct sequencing (DS) with BidDye Terminator v 1.1. cycle sequencing kit and analyzed with a 3130 ABI capillary electrophoresis system. Eight out 13 (61.5%) high Sokal risk patients showed the following mutations: Y253C, S265R, E255K, F359Y, N374S, E255V, E255V, E255V. Three patients progressed during imatinib and second-line inhibitors and died of blastic phase CML at 23, 33, and 69 months. Another patient with intermediate Sokal risk showed D363G mutation at diagnosis, progressed under imatinib, was allografted and he is now alive in major molecular remission (MMR). No low-risk patient carried KD mutation at diagnosis. In conclusion, KD mutations conferring high-level imatinib resistance are present in patients with de novo CML and in some of them lead to disease progression.

We conducted a long-term follow-up retrospective study on 91 consecutive newly diagnosed acute promyelocytic leukaemia (APL) patients. Induction and consolidation therapy were well-tolerated by most patients. Of the 79 patients who were initially treated with the all-trans retinoic acid (ATRA)-containing regimens, there were 3 haemorrhagic deaths during the first period of therapy (4%) and one in consolidation which was due to infection. Following consolidation, molecular assessment of response was performed on 67 patients, and 66 were found to have achieved cytogenetic and molecular remission (98%). After a median follow-up of 100 months (12-192), 10 of the 75 patients who achieved complete remission (13%) relapsed. Seventy-eight percent of the patients were expected to be alive at 14 years from diagnosis, i.e., 90 and 48% of patients of intermediate-low risk and high risk at presentation, respectively (p=0.0009). Sixty-nine patients were in molecular remission after first-line and/or salvage therapy (74%). To date, 4 patients out of the 91 have undergone salvage allogeneic transplant (4%).

Abstract 860 Background: Elderly CML patients treated with Imatinib (IM) in early chronic phase (CP) have similar cytogenetic response and survival compared with younger patients, but they show a lower compliance to standard IM therapy (400 mg/day). Aims: The aim of the study is to investigate if CCgR that has been achieved with standard (daily administration) IM therapy can be maintained with the same dose of IM given intermittently (INTERIM). Methods: The study population is represented by elderly patients (≥ 65 years old) with Ph+ CML and with stable CCgR after at least 2 years of standard IM therapy (daily administration). IM is given at the same dose that was given at the time of enrollment by the following intermittent schedule: 1 week on / 1 week off for the 1st month; 2 weeks on / 2 weeks off for the 2nd and 3rd month; 1 month on / 1 month off from the 4th month thereafter. In cases of loss of CCgR INTERIM was stopped and standard therapy (daily administration) was resumed. After 12 months, the patients who are in continuous CCgR are advised to continue the intermittent study schedule and to be followed indefinitely. The CgR status was evaluated at baseline (by conventional cytogenetics on bone marrow and FISH on peripheral-blood) and every 3 months during the study (only by FISH on peripheral-blood). If FISH (% of Ph+ cells) increased more than 1% in two consecutive examinations, evaluation of marrow cells metaphases was performed to confirm the loss of CCgR and to check for additional cytogenetic abnormalities. Quantitative molecular assessment of BCR-ABL transcript by RQ-PCR on peripheral blood was due at baseline and every 3 months during the study and mutational analysis of ABL was performed in case of loss of CCgR. Results: One-hundred and fourteen patients have been considered eligible, but 17 (15%) refused to enter into the protocol. Out of 97 enrolled patients, 87 started INTERIM, 5 patients (5%) went off the study for major protocol violation before the 3rd month and, at present, 82 patients are ongoing. Of these 82 patients, 52, 30 and 11 completed the 3rd, 6th and 9th month, respectively. The preliminary results of the first 6 months are here reported. The distribution of patients according to FISH results is shown in Fig. 1. Only 1/68 pts (at 6th month) showed an increased >1% in Ph+ cells by FISH but he maintained a CCgR when checked by conventional cytogenetic. As showed in Fig. 2, 96 to 87% of patients maintained a major molecular response MMR (≤0,1) according to International Scale (IS). Conclusions: This study is trying to test the minimum effective dose of Imatinib to maintain the CCgR in elderly CML patients with stable CCgR. The preliminary results at 6 months do not show negative trends both for cytogenetic and molecular response. Therefore, the study is ongoing and all patients are expected to complete the trial time (12 months). Disclosures: No relevant conflicts of interest to declare.

We retrospectively reviewed 139 stage I–II HL patients who were diagnosed and followed up in an Italian northern region (Liguria) from 1995 to 2007, and who received either chemotherapy (CT) alone (mainly doxorubicin, bleomycin, vinblastine, and dacarbazine; ABVD) or a combined modality treatment (chemotherapy + radiotherapy, CT + RT). The two therapeutic groups were comparable for clinical and histologic features. Complete remission rate after CT + RT was higher than what was achieved with CT alone (96% vs. 84%, respectively, p = 0.03). Relapse rate (12%) was the same in both groups and disease-free survival curves were comparable (82% and 83%, p = 0.47). The overall survival of the two therapeutic groups is comparable. No second tumors have been reported among patients receiving chemotherapy alone, whereas a second neoplasia has been diagnosed in four patients (in two cases possibly radiotherapy related) in the CT + RT group (5%, p = 0.09) In conclusion, our retrospective study shows that CT + limited RT is an effective and well-tolerated option for early stage Hodgkin’s lymphoma, even if the use of RT is associated with a certain risk of developing a second tumor. However, four to six courses of ABVD can lead to similar, optimal, long-term disease control without exposing patients to the risk of a second neoplasia.

Abstract 2192 Poster Board II-169 Thanks to its striking effectiveness, imatinib (IM) is the current standard of therapy in chronic myeloid leukemia (CML). However, Interferon-alpha (IFN-alpha) has induced a low but reproducible curative effect in some CML patients, inducing durable remissions lasting even after therapy discontinuation. For this reason, the interest on the possible use of IFN-alpha in the treatment of CML is still substantial, and very recently some newer prospective studies from the French and the German Groups have proposed the re-introduction of IFN-alpha in the front-line treatment of early chronic phase CML (ECP-CML), in association with IM (Rousselot et al, Haematologica 2009;94:abs.1093; Hehlmann et al, Haematologica 2009;94:abs. 0478). We compared the response of 495 ECP-CML patients, enrolled into three different prospective studies promoted by the GIMEMA CML WP (419 treated with imatinib 400mg and 76 treated with imatinib 400mg plus IFN-alpha) (study protocols NCT00511121 , NCT00514488 and NCT00511303 ). Cytogenetic analysis was performed by standard banding techniques and cytogenetic response was rated according to the European LeukemiaNet guidelines. Molecular response was assessed on peripheral blood cells by a standardized quantitative reverse-transcriptase polymerase chain reaction (RQ-PCR) method on an ABI PRISM 7700 Sequence Detector (Perkin Elmer, Faster City, CA). BCR-ABL transcript levels were expressed as a percentage according to the IS. Patients were equally distributed by Sokal risk in the two cohorts. Median follow-up was 43 mos (range, 12- 67) in the IM group and 54 mos (range, 11-63) in the IM+IFN-alpha group. Compliance to IM was excellent in both groups, with 90 to 95% of patients receiving IM 400 mg/daily throughout the follow-up. Conversely, the proportion of patients continuing IFN-alpha dropped from 41% at 12 mos to 18% at 18 mos, 13% at 24 mos, 3% at 36 mos; by the end of the fourth year, all patients were off IFN-alpha. The number of patients in CCgR was higher in the IM+IFN-alpha than in the IM group at 6 mos (60% vs 42%, p=0.002) but not from 12 mos on ( Table 1 ). The number of patients in MMolR was higher in the IM+IFN-alpha than in the IM group at 6, 12 and 24 mos, but not later on ( Table 2 ). Also the number of patients with undetectable Bcr-Abl transcript levels was higher in the IM+IFN-alpha group at 12 months (15% vs 5%, p=0.003) but not later on (19% vs 18% at 48 mos). Table 1 . Number of patients in complete cytogenetic response at different time-points no of patients in CCgR, (%) IM (419 patients) IM+IFN-alpha (76 patients) 6 months 175 (42%) 46 (60%) 12 months 284 (68%) 53 (70%) 24 months 336 (80%) 62 (82%) 36 months 342 (82%) 66 (87%) 48 months 346 (82%) 62 (82%) Table 2 . Percentage of patients in major molecular response (MMolR) evaluated on the entire study group. MMolR p value IM (n.419) IM+PegIFN (n.76) 6 months 34% 58% 12 months 46.5% 67% 0.001 24 months 62% 64.5% 0.7 36 months 58% 65% 0.52 48 months 57% 65% 0.26 These data support the preliminary analysis of the French SPIRIT group, reporting a higher rate of MMolR after initial treatment with IM and IFN-alpha as compared to IM alone. The loss of the difference from 24 mos on could be explained by the fact that almost all patients had discontinued IFN-alpha during the first two years, pointing out that the low compliance to the combination may limit its utility in practice. ACKNOWLEDGEMENT The Italian Association Against Leukemia-lymphoma and myeloma (BolognAIL), The Fondazione del Monte di Bologna e Ravenna, The Italian Ministery of Education (PRIN 2005, No. 20050 63732_003, and PRIN 2007, No 2007F7 AE7B_002), The University of Bologna, The European Union (European LeukemiaNet). Disclosures: Pane: Novartis: Research Funding; Ministero dell'Universita/PRIN: Research Funding; Regione Campania: Research Funding; Ministero della Salute/Progetto integrato Oncologia: Research Funding. Saglio: Celgene: Honoraria; Novartis: Honoraria.

Objectives: Infections are the major cause of morbidity and mortality in patients with acute myeloid leukaemia (AML). They primarily occur during the first course of induction chemotherapy and may increase the risk of leukaemia relapse, due to a significant delay in consolidation therapy. The intensification of induction chemotherapy and the use of non-conventional drugs such as fludarabine are considered responsible for the increased risk of infections. Methods: In this study, we retrospectively analysed the infections occurred in 224 newly diagnosed AML patients ≤65 yr, consecutively treated between 1997 and 2002 with an induction regimen including fludarabine, arabinosyl cytosine and idarubicin, with or without etoposide (FLAI/FLAIE), in the context of three multicentric prospective trials (AML97, AML99, AML02). Results: During the induction phase, 146 (65%) patients experienced fever of undetermined origin (FUO), 30 (13%) and 47 (21%) patients had Gram-negative and positive bacteremias, respectively, and 10 (4%) patients developed a probable/proven invasive fungal infection (IFI). The fatality rate for Gram-negative, Gram-positive bacteremias and probable/proven IFI was 10%, 8% and 60% respectively. During consolidation, 75 (35%) patients had FUO, 43 (20%) and 40 (19%) patients had Gram-negative and positive bacteremias, respectively, and 5 (2%) patients developed a probable/proven IFI. The fatality rate for Gram-negative, Gram-positive bacteremias and probable/proven IFI was 14%, 5% and 80% respectively. Interestingly, the overall incidence of microbiologically documented infections during induction was 38% and the incidence of probable/proven IFIs during the induction/consolidation programme was 7%. No infections caused by viruses or opportunistic pathogens were observed neither during induction, nor during consolidation. Conclusions: These data, although retrospectively collected, suggest that fludarabine-based chemotherapy is not associated with an increased incidence of infections, in particular IFIs, compared to conventional regimens commonly used for AML induction.