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Chronic Myeloid Leukemia is a clonal disorder characterized by the presence of the Ph-chromosome and the BCR-ABL tyrosine-kinase (TK). Target-therapy with Imatinib has greatly improved its outcome. Deeper and faster responses are reported with the second-generation TKI Nilotinib. Sustained responses may enable TKI discontinuation. However, even in a complete molecular response, some patients experience disease recurrence possibly due to persistence of quiescent leukemic CD34+/lin−Ph+ stem cells (LSCs). Degree and mechanisms of LSCs clearance during TKI treatment are not clearly established. The PhilosoPhi34 study was designed to verify the in-vivo activity and timecourse of first-line Nilotinib therapy on BM CD34+/lin−Ph+ cells clearance. Eighty-seven CP-CML patients were enrolled. BM cells were collected and tested for Ph+ residual cells, at diagnosis, 3, 6 and 12 months of treatment. FISH analysis of unstimulated CD34+/lin− cells in CCyR patients were positive in 8/65 (12.3%), 5/71 (7%), 0/69 (0%) evaluable tests, respectively. Per-Protocol analysis response rates were as follows: CCyR 95% at 12 months, MR4.5 31% and 46% at 12 and 36 months, respectively. An exploratory Gene Expression Profiling (GEP) study of CD34+/lin− cells was performed on 30 patients at diagnosis and after, on 79 patients at diagnosis vs 12 months of nilotinib treatment vs 10 healthy subjects. Data demonstrated some genes significantly different expressed: NFKBIA, many cell cycle genes, ABC transporters, JAK-STAT signaling pathway (JAK2). In addition, a correlation between different expression of some genes (JAK2, OLFM4, ICAM1, NFKBIA) among patients at diagnosis and their achievement of an early and deeper MR was observed.

BACKGROUND: Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder with heterogeneous biological and clinical features. The biomolecular mechanisms of CML response to tyrosine-kinase inhibitors are not fully defined. OBJECTIVE: We undertook a gene expression profiling (GEP) study of selected bone marrow (BM) CD34+/lin-cells of chronic-phase CML patients at diagnosis and after 12 months of TKI nilotinib to investigate molecular signatures characterizing both conditions. METHODS:We selected and counted BM CD34+/lin- cells of 30 CML patients at diagnosis and during 3, 6 and 12 months of first-line nilotinib treatment. GEP was performed between CD34+/lin- cells of patients at diagnosis and the same patients after 12 months of nilotinib. RESULTS: The number of BM CD34+/lin- cells dramatically decreased after 3, 6 and 12 months of nilotinib. GEP detected 264 statistically significant differentially expressed genes at diagnosis vs. 12 months of nilotinib. Functional enrichment analysis revealed groups of genes belonging to 14 pathways differentially active during nilotinib treatment. CONCLUSIONS: In conclusion, lipid, glucose and sphingolipid metabolism, insulin resistance, complement and coagulation, platelet activation, cytoscheleton, cell adhesion, transport, B cell differentiation, RAS-signaling pathway, proliferation, growth factors, and apoptosis were significantly deregulated between CML patients at diagnosis and after 12 months of nilotinib.

Chronic myeloid leukemia (CML) is characterized by the constitutive tyrosine kinase activity of the oncoprotein BCR-ABL1 in myeloid progenitor cells that activates multiple signal transduction pathways leading to the leukemic phenotype. The tyrosine-kinase inhibitor (TKI) nilotinib inhibits the tyrosine kinase activity of BCR-ABL1 in CML patients. Despite the success of nilotinib treatment in patients with chronic-phase (CP) CML, a population of Philadelphia-positive (Ph+) quiescent stem cells escapes the drug activity and can lead to drug resistance. The molecular mechanism by which these quiescent cells remain insensitive is poorly understood. The aim of this study was to compare the gene expression profiling (GEP) of bone marrow (BM) CD34+/lin- cells from CP-CML patients at diagnosis and after 12 months of nilotinib treatment by microarray, in order to identify gene expression changes and the dysregulation of pathways due to nilotinib action. We selected BM CD34+/lin- cells from 78 CP-CML patients at diagnosis and after 12 months of first-line nilotinib therapy and microarray analysis was performed. GEP bioinformatic analyses identified 2,959 differently expressed probes and functional clustering determined some significantly enriched pathways between diagnosis and 12 months of nilotinib treatment. Among these pathways, we observed the under expression of 26 genes encoding proteins belonging to the cell cycle after 12 months of nilotinib treatment which led to the up-regulation of chromosome replication, cell proliferation, DNA replication, and DNA damage checkpoint at diagnosis. We demonstrated the under expression of the ATP-binding cassette (ABC) transporters ABCC4, ABCC5, and ABCD3 encoding proteins which pumped drugs out of the cells after 12 months of nilotinib. Moreover, GEP data demonstrated the deregulation of genes involved in the JAK-STAT signaling pathway. The down-regulation of JAK2, IL7, STAM, PIK3CA, PTPN11, RAF1, and SOS1 key genes after 12 months of nilotinib could demonstrate the up-regulation of cell cycle, proliferation and differentiation via MAPK and PI3K-AKT signaling pathways at diagnosis.

In the PhilosoPhi34 study (EudraCT: 2012-005062-34) on 87 CP-CML patients, we analyzed the gene expression profiling (GEP) of bone marrow (BM) CD34+/lin- cells of 79 patients with chronic-phase chronic myeloid leukemia (CP-CML) patients at diagnosis and after 12 months of nilotinib treatment (Pungolino et al. AM J Hematol. 2018). FISH analyses identified CD34+/lin- Ph+ cells in all 79 CML-CP patients at diagnosis. 78/79 patients achieved at least a complete cytogenetic response after 12 months of nilotinib whereas 1/79 patients relapsed at 12 months. No Ph+ nuclei were detected in 78/79 patients at 12 months. We have demonstrated that genes involved in the JAK-STAT signaling pathway, the cell cycle, and the ATP-binding cassette (ABC) transporters were significantly over expressed in patients at diagnosis compared to 12 months of nilotinib treatment (Trojani et al, PLoS One. 2019). In this preliminary study, we isolated BM CD34+/lin- cells from 9 healthy donors (CTRLs). We investigated the gene expression profiling of 79 CP-CML patients at diagnosis vs. the same patients after 12 months of nilotinib treatment (12 months) vs. 9 CTRLs using Affymetrix HTA 2.0. Data was preprocessed and normalized using RMA and ComBat. Selection of differentially expressed genes (DEg) was performed at diagnosis vs. 12 months of nilotinib vs. CTRLs, using Statistical Analysis for Microarrays (SAM) on 3 groups and a Benjamini Hochberg false discovey rate threshold of 5%, followed, for significance comparisons, by a pair-wise SAM test. We focused on 34 genes of the cell cycle and mitosis, 6 genes belonging to the JAK-STAT signaling pathway, and the ABC transporter gene ABCD3 which were significantly under expressed at diagnosis vs. 12 months of nilotinib vs. CRTLs (Tab.1). In the cell cycle, we found that ORC2, ORC4, ORC5, MCM6, and HDAC2 (G1 phase) were progressively significantly down regulated at diagnosis vs. 12 months vs. CTRLs. We noticed HDAC2 which showed the high fold changes of 2.89 and 4.29 in the comparison between 12 months vs. CTRLs and between diagnosis vs. CTRLs, respectively. This gene plays a crucial role in CML, as HDAC inhibitors treatment represent an effective strategy to target leukemic stem cells in CP-CML patients receiving tyrosine kinase inhibitors. CCNA2, CDK7, CDC6, DBF4 (S phase), WEE1, PRKDC, ATM, MDM2, CCNB1 (G2 phase), and TTK, MAD2L1, BUB1, BUB3, ANAPC4, CDC27, SMC3, YWHAE, and YWHAZ (M phase) were progressively down regulated at diagnosis vs. 12 months vs. CTRLs. Among them, SMC3, YWHAE and YWHAZ showed the following high fold changes in the comparison between 12 months vs. CTRLs and between diagnosis vs. CTRLs: 2.31 and 3.15, 2.59 and 3.94, 2.75 and 4.15, respectively. Notably, the proto-oncogene MDM2 which promotes the development of tumors by targeting p53, was progressively up regulated in CTRLs vs. 12 months vs. diagnosis. In the mitosis, we detected that 10 genes playing a crucial role in mitotic chromosome organization, were progressively under expressed at diagnosis vs. 12 months vs. CTRLs (Tab.1). Notably, CLAPS2, ZW10 and ANLN (hematopoietic cell differentiation) regulate the exit from mitosis. NDC80, SMC4, ZNF207, and NEK2 take part in the mitotic sister chromatid segregation whereas CENPE and SMC2 are mitotic cell cycle check points. In the JAK-STAT signaling pathway, SOS1, PIK3CA, IL7, JAK2, STAM, and PTPN11 were progressively up regulated in CTRLs vs. 12 months vs. diagnosis (Tab.1). ABCD3, encoding a protein which pumped drugs out of the cells, was progressively under expressed at diagnosis vs. 12 months vs. CRTLs as shown in Tab.1. In conclusion, we found progressive gene expression changes in BM CD34+/lin- cells of 79 CP-CML patients at diagnosis vs. 12 months of nilotinib vs. the normal cell counterparts of 9 CTRLs in the cell cycle, JAK-STAT, and the ABC transporter ABCD3. FISH analyses demonstrated that the BM CD34+/lin- cells of 78/79 patients after 12 months of nilotinib were Ph-negative. Despite, our GEP results suggested that BM CD34+/lin- cells after 12 months of nilotinib treatment and the normal cell counterparts differed mostly in the expression of genes regulating the cell cycle and the JAK-STAT signaling pathway. Disclosures Rossi: Daiichi-Sankyo: Consultancy; Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; Mundipharma: Honoraria; BMS: Honoraria; Sandoz: Honoraria. Elena:Novartis: Consultancy; Pfizer: Consultancy. Iurlo:Pfizer: Other: Speaker Honoraria; Incyte: Other: Speaker Honoraria; Novartis: Other: Speaker Honoraria.

Background Chronic Myeloid Leukemia (CML) is a clonal myeloproliferative disorder which molecular base is represented by the bcr-abl fusion gene, encoding for the constitutionally activated BCR-ABL tirosine-kinase. Three Tirosin-Kinase Inhibitors (TKI) are approved for first line treatment: Imatinib (IM) and the second generation (2G) TKI Nilotinib (NIL) and Dasatinib. 2G TKI are known to provide faster and deeper molecular responses (MR) compared to Imatinib, but serious toxicities may hamper long term treatment with these molecules. Furthermore, 2G TKI were usually employed as second line after IM failure, while the inverse sequence from second to first generation TKI (like an induction-maintenance model) has not been explored yet. We used this schedule in a small group of patients in the PhilosoPhi34 study (EudraCT: 2012-005062-34), a clinical trial designed by the REL (Rete Ematologica Lombarda) cooperative group. This study was composed by three consecutive phases: a Recruitment Phase, a Core Phase (CP) in which patients received NIL 300 mg BID for 12 month (mos), and an Observational Phase (OP), restricted for patients who obtained at least complete cytogenetic response at the end of the CP. During OP, treatment choice was up to the physician and any TKI approved for first line treatment could be used, including IM. In 2017 we presented preliminary data showing that a 12-mos-NIL treatment followed by IM appears as a safe and effective choice for first line therapy in chronic phase CML. Fluctuations in BCR/ABL ratio were similar between IM and NIL treated pts, and the probability of loss of MR4 or MR3 was the same in the two groups; furthermore, despite fluctuations, MR was maintained or improved over time in IM subgroup. Our purpose is to verify these data after 24 mos follow up (FU) at the end of OP. Methods We analyze PhilosoPhi34 database; MR is reported at 3, 6 and 12 mos during the CP and every 6 mos during the OP. The last pt completed the 24 mos of OP in June 2018. Database is still open, evaluations ongoing, and some data can be missing yet: our preliminary observations concern pts with available data of 24 mos OP. Results Seventy-nine pts started the OP. Fourteen pts switched to IM during the OP (Table 1) due to high cardiovascular risk or grade 1-2 chronic AEs . Only 11 pts started IM since the beginning of OP, and we consider these pts in our analysis. Sokal score was high in 2 pts (18%), intermediate in 5 (45.5%), low in 4 (36.5%). At the beginning of OP, 6 pts had a MR ≥ 4 (54.5%), 5 had MR3 (45.5%). At 12 mos of the OP, 7 had MR ≥ 4, 3 had MR3 and 1 had lost MR3 with PCR 0.192%IS (1/5, 20%). At 24 mos of the OP, 9 had MR ≥ 4 (81,8%), and 2 had MR3. Notably, none of pts lost MMR; 2/3 pts(66%) improved response from MR 3 to MR 4 and the pt who transiently lost MMR at 12 mos, recovered it at 24. Sixty-four pts maintained 2G TKI: 62 NIL, 2 other TKI (not considered for analysis). Of them, 4 were lost during this phase: 2 within the first year of OP, other 2 within 12 and 24 mos of OP. In the NIL group, Sokal score was high in 10 pts (16.6%), intermediate in 19 (31.6%) and low in 31 (51.6%). At the beginning of OP, 32 pts had MR ≥ 4 (51.6%), 21 had MR3 (33.8%) and 9 less than MR 3 (14.5%). Responses were improved over time: at 12 mos, 36 pts had MR ≥ 4 (60%), 20 had MR3 (33%) and 4 less than MR3 (6%). At 24 mos 46 pts had MR ≥ 4 (78%), 8 MR3 (13.5%) and 4 less than MR3 (8,5%), Among them, 1 pt experienced disease progression due to a mutation. In particular, during the second year of OP, 11 pts improved response from MR3 to MR ≥ 4(11/20, 55%). Discussion Our data show progressive MR improvement in both IM and NIL group. In particular, risk of loss of MMR is not increased in IM group. More data, more balanced groups and a longer FU are necessary to further confirmations, but after three years of FU, we consider this combination of NIL-followed-by-IM a possible strategy for first line treatment in chronic phase CML, in particular for pts with cardiovascular risk factors. Disclosures Rossi: Janssen: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; Gilead: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Honoraria; BMS: Honoraria; Sandoz: Honoraria; Pfizer: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees.

The study analyzed 30 chronic phase CML patients at diagnosis and at 3, 6 and 12 months of first-line nilotinib treatment. As optimal molecular response was achieved at 3, 6 and 12 months after nilotinib in all the 30 patients (figure 1), we established cut off values of molecular response (MR) to define groups of CML patients (n =30), and to investigate differences of gene expression profiles between patients at diagnosis based on the MR achieved after 3, 6 and 12 months of nilotinib, respectively. We used the following cut off values: 1% IS at 3 months of nilotinib, 0.1% IS at 6 months of nilotinib, and 0.01% IS at 12 months of nilotinib. Patients were divided into 2 groups based on MR values of each patient at 3 months of nilotinib: group A (n =24) with MR ≤1.0% IS and group B (n =6) with MR >1% IS. Based on the values of MR at 6 months of nilotinib, patients were divided into 2 groups: group C (n =22) with MR ≤0.1% IS and group D (n =8) with MR >0.1% IS. At 12 months of nilotinib, patients were divided into the following groups: group E (n =18) with MR ≤0.01% IS and group F (n =12) with MR >0.01% IS. Gene expression profiling (GEP) on the selected bone marrow (BM) CD34+/lin- cells of 30 CML patients at diagnosis was performed using Affymetrix GeneChip HTA 2.0. GEP data was preprocesses using RMA. SAMR and GSEA were used to detect differentially expressed genes and pathways (i.e. MSigDB Canonical pathways and GOBP gene sets) associated with the different groups, respectively. In both cases, correction for multiple testing was performed using the false discovery rate procedure with a threshold 0.05 for SAMR and 0.25 for GSEA as suggested by the software developers. GSEA detected significant differences in the transcriptional signature between group A and group B associated with the MR at 3 months as well as between group C and group D in respect to the MR at 6 months of nilotinib, whereas no genes were identified as significantly differentially expressed. Based on the MR at 3 months, we identified Reactome pathways "P130 cascade" and "GRB2 SOS linkage to MAPK signaling for integrins" significantly upregulated in group A compared to group B. FGA, FGB, FGG, APBB1IP, ITGA2B and CRK genes contributed to call the pathways upregulated. In vitro studies (Ding J et al. PloS One, 2013) demonstrated that nilotinib induced dephosphorilation of the BCR-ABL1 target CRK oncogene which acts in the CML hematopoietic stem cells like an adaptor in diverse signaling pathways and cellular processes playing an apoptotic role in CML. Our GEP results highlighted that the Reactome pathway involved in MAPK signaling (CRK gene) wasover expressed in CML patients with a better MR ≤1% IS at 3 months of nilotinib. Pathway "aminoacid and amine transport across the plasma membrane" was also significantly over expressed, whereas "lipid metabolism" was significantly down regulated (genes AKR1C1 and ANGPTL3) in group A compared to group B, respectively. Based on the MR at 6 months, GEP results showed that "positive regulation of cytokine secretion" and "interleukin 1 secretion" were significantly upregulated in group C compared to group D, involving PYCARD8, NLRP2, NLRC4, NLRP3 and CARD8 genes. Of note, PYCARD and CARD8 represent key mediators, which promote caspase-mediated apoptosis processes involving the recruitment of certain recognition receptors, such as NLRP2, NLRP3 and NLRC4. In addition, CARD8 and PYCARD promote apoptosis inhibiting NFKB activation. In conclusion, the study showed that MAPK signaling for integrins and amine transport across the plasma membrane were significantly over expressed in CML patients with a MR ≤1.0% IS while lipid metabolism was significantly over expressed in CML patients with a MR >1% IS after 3 months of nilotinib. After 6 months of nilotinib, positive regulation of cytokine secretion and interleukin 1 secretion were significantly over expressed in CML patients with a MR ≤0.1 IS compared to patients with a MR >0.1% IS. We identified distinct sets of genes involved in apoptotic processes differentially expressed in 30 CML patients based on the MR at 3 months as well as 6 months of first-line nilotinib treatment. Studies in a larger cohort of CML patients are ongoing to define the expression, role and functions of the genes regulating apoptosis CRK, PYCARD and CARD8 as candidate prognostic factors for molecular response to first-line nilotinib treatment. Disclosures No relevant conflicts of interest to declare.

Background. Chronic Myeloid Leukaemia (CML) can be effectively treated with the first generation Tyrosine Kinase Inhibitor (TKI) Imatinib, and more effectively with the second generation TKI, like Nilotinib. However, despite the deeper and faster responses induced by nilotinib in a large proportion of patients, the possible eradication of the pathological stem cells is not yet clearly elucidated. In fact, in vitro data suggest that quiescent stem cells are not sensitive to Bcr/Abl inhibition (Corbin AS, et al 2011; Hamilton A, et al 2012). A preliminary in-vivo study (Defina M, et al 2012) shows that in patients in CCyR even after short-term of nilotinib therapy, residual leukemic progenitors are rarely detected. Methods. On behalf of Rete Ematologica Lombarda (REL), Italy, we designed a single arm prospectic study, PhilosoPhi34 (EudraCT: 2012-005062-34), with the aim to investigate the efficacy of nilotinib 300 mg BID in obtaining the disappearance of Bone Marrow (BM) leukemic stem cells (CD34+/lin-Ph+) in newly diagnosed CP-CML. Primary objective of the study: to enumerate the BM CD34+/lin-Ph+ cells at the end of 6 months of treatment. Secondary objectives: to enumerate the BM CD34+/lin-Ph+ cells at 3 and 12 months; to assess the percentage of patients showing MR ≤10% IS at 3 months and MR ≤1% IS at 6 months and the MMR IS and MR4.5 IS by 3, 6 and 12 months of treatment. BM blood samples (range of 5-20 ml) were collected at diagnosis and after 3, 6 and 12 months of nilotinib treatment. BM mononuclear cells were purified by density gradient centrifugation and then CD34+/lin- cells were isolated using Diamond CD34 Isolation Kit (Miltenyi Biotec). The purity of CD34+/lin- cells was about 97% as determined by flow cytometry. BM CD34+/lin- cells were counted and a range of 100,000-800,000 has been noted at diagnosis. After the treatment we observed that the number of CD34+/lin- cells dramatically decreased after 3 (1,000-600,000), 6 (1,000-260,000) and 12 months (100-130,000). In particular, CD34+/lin- cells were even less than 1000 at 12 month of treatment. In order to verify the disappearance of leukemic stem cells, isolated CD34+/lin- cells were tested by standard FISH (i.e. to categorize a sample as negative at least 200 nucleus were examined). From April 2013 and June 2015 we enrolled 87 pts, as for protocol. We report here the preliminary results. Results. Of 56 patients in CCyR after 6 months of treatment, FISH performed on BM CD34+/lin- cells nuclei was evaluable in 51 cases (5 negative cases were excluded because of less than 200 nucleus were analysed). In 4 out of 51 patients (7.8%), Ph+ nuclei were detected. The Sokal score of these 4 patients was 1 low, 2 intermediate and 1 high risk with a ratio (positive nuclei/total nuclei) of 295/300, 1/200, 2/92, 3/300, respectively. Among 58 patients tested at 3 months and 44 tested at 12 months of treatment, the number of evaluable patients was 48 and 37, respectively; 8/48 (16.6%) and 0/37 (0%) patients showed Ph+ nuclei. Only 2 out of 8 positive patients had a high Sokal score. Regarding efficacy of treatment, Table 1 summarizes the MRs IS observed after 3, 6 and 12 months of treatment in 71, 57 and 41 patients, respectively. Conclusion. Data of this prospective study confirms that nilotinib 300 mg BID, rapidly and progressively induces the clearance of BM CD34+/lin-Ph+ cells in CP-CML patients. In particular, on CD34+/lin- cells, after 6 months of treatment, only 7.8% of patients showed positive nuclei. On 37 patients after 12 months of treatment, no positive nuclei were detected. So far, the kinetic of reduction of such cells seems not influenced by Sokal score. According to international studies, PhilosoPhi34 shows a very high efficacy of Nilotinib to induce MRs in CP-CML patients, at the standard time points. Table 1. Molecular Response (MR) in CP-CML patients treated with Nilotinib 300mg BID from diagnosis. MR IS 3 months 6 months 12 months ≤10% 67/71 94% 57/57 100% 40/41 97.50% ≤1% 57/71 80% 55/57 96.50% 40/41 97.50% ≤0.1% 17/71 24% 41/57 72% 35/41 85% ≤0.01% 3/71 4% 19/57 33% 20/41 48.70% MR4.5(UD) 2/71 2.80% 10 (6)/57 17.5% (10.5%) 15 (9)/41 36.5% (22%) UD: undetectable We acknowledge all REL Colleagues for their collaboration and Novartis SpA for the partial financial support to the study. Disclosures No relevant conflicts of interest to declare.

This study aimed to determine the gene expression profiling (GEP) of bone marrow (BM) CD34+/lin- cells of CML patients at diagnosis and after nilotinib treatment.Microarray was performed on 30 CML patients at diagnosis as well as 8 patients after 12 months of nilotinib treatment using the latest generation Affymetrix GeneChip HTA 2.0 to further investigate genomic complexity. Bone marrow blood (in a range of 5-20 ml) samples were collected from patients at diagnosis and after 3, 6 and 12 months of nilotinib treatment. BM mononuclear cells were purified by density gradient centrifugation at 800 rpm for 20 min and soon after CD34+/lin- cells were isolated using Diamond CD34 Isolation Kit (Miltenyi Biotec). The purity of CD34+/lin-cells was about 97% as determined by flow citometry and the cells were counted at diagnosis and after the treatment with nilotinib (at 3, 6, and 12 months). BM CD34+/lin- cells of 30 patients at diagnosis and after 3 and 6 months of nilotinib were resuspended in RNAlater (Ambion, Life Technologies) and stored at -20°C until RNA extraction was performed. Total RNA was extracted from BM CD34+/lin- cells using MagMAX 96 Total RNA Isolation Kit (Ambion). BM CD34+/lin- cells were counted and a range of 100,000-800,000 has been noted at diagnosis. cRNA was prepared according to OvationPico WTA System V2 kit followed by Encore Biotin Module Kit (NuGEN). Ultimately, cRNA was hybridized to HTA 2.0 and signals were scanned by Affymetrix GeneChip Scanner 3000 following the manufacturer’s instructions. We observed that the number of CD34+/lin- cells dramatically decreased at 3 months (1,000-600,000), after 6 months (1,000-260,000) and after 12 months (100-130,000). In particular, CD34+/lin- cells were even less than 1000 after 12 months of nilotinib. If the number of CD34+/lin- cells after 12 months of nilotinib was less than 1000, we directly resuspended the cells in Prelude direct Lysis module (NuGEN) and microarray experiments were performed without RNA extraction. In this case, cRNA was prepared using Ovation One Direct System kit followed by Encore Biotin Module Kit (Nugen) and finally hybridized to the HTA 2.0. Microarray experiments were performed on CD34+/lin- cells of 30 CML patients at diagnosis with HTA 2.0. Moreover, we performed microarray experiments on CD34+/lin- cells of 8 CML patients at diagnosis vs. 8 CML patients after 12 months of nilotinib using HTA 2.0. Data was preprocessed and normalized using Robust Multi-array Average (RMA) algorithm. The Significant Analysis of Microarrays (SAM) was used to identify genes with statistically significant changes in expression in CML patients at diagnosis and at 12 months of treatment. P-values were corrected for multiple testing using false discovery rate. In conclusion, as far as we know, this is the first study which has isolated BM CD34+/lin-cells from CML patients at diagnosis and after nilotinib treatment. We observed a wide variety of the number of CD34+/lin- cells in 30 CML patients at diagnosis as well as after 3, 6 and 12 months of nilotinib. In particular, CD34+/lin- cells of CML patients at diagnosis were over 100.000. RNA was extracted and cRNA was prepared with OvationPico WTA System V2 kit followed by Encore Biotin Module Kit (NuGEN) and finally hybridized to HTA 2.0. On the other hand, the number of CD34+/lin- cells of CML patients after 12 months of nilotinib markedly decreased as low as 100 cells. In this case, we decided to avoid RNA extraction from the cells and we directly prepared cRNA using Ovation One Direct System kit and Encore Biotin Module Kit (Nugen) followed by the hybridization to the HTA 2.0 Array. To increase the statistical power in biomarker identification, we combined samples pre-processed with different experimental protocols (NuGEN) using ComBat, an empirical Bayes framework that adjusts data for batch effects and is robust to outliers in small datasets. Principal component analysis applied to the expression data before and after ComBat adjustment shows that the adopted normalization procedure effectively removes the systematic bias introduced by different protocols. Disclosures No relevant conflicts of interest to declare.

Background CML is a clonal disorder characterized by the presence of the Philadelphia (Ph) chromosome which encodes for the bcr-abl tyrosine-kinase (TK). Target therapy with the TK inhibitors (TKIs)) has greatly improved its outcome. Treatment with second generation TKIs - e.g. nilotinib (NIL) - results in deeper and faster responses and prevents disease progression. Sustained responses may enable TKI discontinuation. However, even in the event of qPCR negativity, a fraction of patients (pts) experience disease recurrence possibly due to persistence of quiescent leukemic stem cells (LSCs). Degree and mechanisms of LSCs clearance during TKI treatment are not established yet and conflicting results are reported in the literature. Work from the group of Bocchia (Bocchia 2008; Defina 2012) showed reduction of LSCs during long term imatinib (IM) therapy; moreover, in CCyR pts residual LSCs are more rarely detected after NIL compared to IM therapy and, in a small fraction of pts this occurs after very short-term NIL therapy. This data conflicts with in vitro evidence that NIL is not superior to IM in inducing growth suppression in CML LSCs (Konig, 2008). To verify the in vivo activity and time-course of first-line NIL therapy on bone marrow (BM) Ph+ stem cells (CD34+/lin-) clearance, on behalf of the Rete Ematologica Lombarda (REL) the PhilosoPhi34 study (EudraCT: 2012-005062-34) was designed. Primary efficacy endpoint was to measure the rate of BM residual CD34+/lin-Ph+ cells in CCyR pts at 6 months of treatment. Methods BM cells were collected and stored at diagnosis and at 3,6 and 12 mos of treatment. CD34+/lin- cells were purified using a Diamond CD34 Isolation Kit Miltenyi (97% of purity). FISH analysis of selected unstimulated CD34+/lin- cells was performed according to standard procedures; considering the low sensitivity of the test, in order to define the test as negative at least 200 nuclei were examined. The A'Hern single stage design was chosen for the present study; considering the CCyR results obtained in the ENESTnd study and the anticipated number of un-evaluable tests, a minimun of 87 pts were required. Results Enrolment of the 87 pts was completed by June 2015. Table 1 summarises pts' characteristics and response to treatment. FISH results are as follows: at 3 mos, 8/65 (12,3%; CI 95%: 2,3%-15,7%) evaluable FISH tested positive (10 negative tests not evaluable); at 6 mos 5/71 (7%; CI 95% :2,3-15,7%) evaluable FISH tested positive (7 negative tests not evaluable); at 12 mos, 0/68 (0%; CI95%:0,0-5,2%) evaluable FISH tested positive (9 negative tests not evaluable). At any time point, Sokal score did not predict for FISH results. However, as outlined in Table 2, H-Sokal score pts are less prevalent among pts who achieve a CCyR, a requirement for FISH analysis. Of the 4 pts who failed the treatments' objectives by 12 mos, 1 was in CCyR with detectable residual CD34+/lin-Ph+ cells at 3 mos; 2 were not in CCyR and with residual CD34+/lin-Ph+ cells at 3mos; 1 was in CCyR and with CD34+/lin-Ph- cells at 3 and 6 mos but with increasing qPCR. Only 1 pt with CD34+/lin-Ph- cells at all time points and with optimal molecular response harboured a NIL-resistant mutation at 26 mos of treatment. None of the 22 pts (including 4 H-Sokal score pts = equal proportion of study cohort) in Molecular Response (MR) 3.0 at 3 mos had a positive FISH at 3 and 6 mos or failed treatment at follow-up. Conclusion. Our final results on the whole cohort of pts confirm our preliminary data on the efficacy of NIL 300 g BID in early clearance of BM LSCs (CD34+/lin-Ph+) in newly diagnosed CP-CML patients tested at 3, 6 and 12 mos of treatment. Moreover, according to our data, fast disease debulking seems crucial for obtaining BM LSCs clearance and it can be speculated that the same mechanism responsible for this early MR 3.0 achievement is also capable of preventing H-Sokal risk pts from failing treatment. Disclosures Orlandi: Ariad: Honoraria; BMS: Honoraria; Novartis: Honoraria.

1. In a multicenter, placebo-controlled, double-blind clinical trial in 156 elderly patients with psychopathologic symptoms, glycosaminoglycan polysulfate was found to be a therapeutlcally effective agent in the treatment of the earliest manifestations of a dementing process. 2. Treatment with glycosaminoglycan polysulfate in the daily dosage of 600 LRU, administered on the basis of a divided dosage schedule for 24 weeks, was significantly superior to an inactive placebo on several several outcome measures including the SCAG Total and factor scores (i.e., Cognitive Dysfunction, Withdrawal, Agitation/Irritability and Depression), the NOHLIS Total and Fatiguability factor scores, the MMSE, the HAM-D Total and Vegetative Symptoms factor score and the CGI Severity of Illness and Global Improvement. 3. The drug was well tolerated; vital signs and laboratory measures did not show clinically significant changes within the experimental period.

Chronic myeloid leukemia (CML) is a disease of stemming from genetic damage to a hematopoietic stem cell. Despite nilotinib being a very effective drug for the treatment of CML, drug resistance can emerge. In the contest of the REL-PhilosoPhi34 study on behalf of the Rete Ematologica Lombarda, we performed an exploratory study aimed to identify the gene expression signature of bone marrow (BM) CD34+/lin- cells of CML patients at diagnosis as well as after 12 months of nilotinib to investigate the genes and pathways responsible for the response or resistance to nilotinib. Microarray experiments were performed using the latest generation Affymetrix GeneChip HTA 2.0 to further investigate genomic complexity. The study was developed in two steps as follows: In the first step we analyzed 30 CML patients and from the comparison between the BM CD34+/lin- cell counts from each patient at diagnosis and after 3 and 6 months of nilotinib, patients were divided into 2 classes: class 1 (n=24) showed highly reduced levels of CD34+/lin- cells while class 2 (n=6) demonstrated increasing levels of CD34+/lin- cells after 3 and 6 months of nilotinib, respectively (Fig.1). The 30 patients can be divided into 6 groups showing different patterns of CD34+/lin- cellularity (Figure 1). Data was preprocessed and normalized using Robust Multi-array Average (RMA) algorithm. The Significant Analysis of Microarrays (SAM) was used to identify genes with statistically significant changes in expression in CML patients. P-values were corrected for multiple testing using false discovery rate. No transcripts were selected as differentially expressed using this threshold. However, if a nominal significance level alpha equal to 0.05 is adopted together with a fold-change threshold equal to 2 (absolute value), 56 transcripts were selected in the comparison between the 2 groups of CML patients. Among them, we focused on NFKBIAgene which was over expressed in class 1 compared to class 2.NFKBIA is involved in 68 pathways regulating apoptosis (PI3K,NF-kB) and encodes IkBα protein belonging to the NF-kB pathway which is a potential downstream target of BCR-ABL1 due to its role in regulating cell survival and proliferation. Of note, 31/56 transcripts are located on chromosome 15 suggesting that this region could be crucial for transcriptional regulation of CML correlated to nilotinib response. The second step analyzed the GEP of CD34+/lin- cells of 8 patients at diagnosis (class 1) vs. the same 8 patients after 12 months of nilotinib (class 2) to investigate the gene expression changes and the pathways induced by nilotinib treatment. Data was preprocessed and analyzed as described above. 247 probes (corresponding to 51 genes and 180 non-annotated transcripts) were selected with a p-value lower than 0.05 after multiple testing correction and using a fold-change threshold equal to 3 (absolute value). Functional enrichment analysis was performed using DAVID and highlighted the following pathways and genes: ¯ Defense response and immune system: CAMP, CRISP3, CYBB, RGS1, CEACAM8, LTF (cell growth and differentiation), MNDA and HP (positive regulation of apoptosis) were over expressed in class 2 with high fold changes of 7.65, 9.95, 4.40, 3.47, 4.28, 3.61, 3.60, 3.95, respectively ¯ Transcriptional regulation and cell cycle: MMP8was under expressed in class 1 with the high fold change of 8,94 ¯ S100A12, S100A8, S100A9 (regulation of the cell cycle and differentiation) were over expressed in class 2 with the FC of 8.68, 3.96, 4.49, respectively ¯ RNA5S-ribosomal pseudogenes 310-311-312-313-314-315-316-317-320-363 were downregulated in class 2 ¯ 10 small-nuclear-RNAs and 11 small-nucleolar RNA were differently deregulated between the 2 classes ¯ APOC1, PLBD1 (lipid metabolism) were overexpressed and underexpressed in class 1, respectively In conclusion, this is the first study of GEP of CD34+/lin- cells with HTA 2.0 which demonstrated that 51 genes mostly involved in immune system, transcriptional regulation and cell cycle were significantly differently expressed from the comparison between CML patients at diagnosis and after 12 month of nilotinib. Ongoing studies are focused on examining the genetic and biologic mechanisms underlying nilotinib response or resistance to predict response or failure providing new insights into the molecular mechanisms in CML. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

The most common staging systems for CLL were developed many years ago and are based on blood cell count and the presence of enlarged lymph nodes by physical exam. Many studies have tried to identify prognostic factors in early stage patients. A recent paper (Muntanola et al: Abdominal Computed Tomography Predicts Progression in Patients With Rai Stage 0 CLL. J Clin Oncol. 25:1576-1580) showed that patients with Rai 0 disease and a pathologic abdominal CT scan had a reduced time to progression (TTP), more similar to Rai stage I disease; however CT cannot be used routinely, especially in patients with early stage CLL, whose life expectancy may be very long. When compared to CT, ultrasonography (US) can be used at diagnosis and in follow-up, when it can show progression of abdominal lymph nodes. Patients and Methods The aims of the study were to investigate: 1) if a pathologic ultrasonography (PU) showing the presence of abdominal lymphadenopathy at diagnosis could allow identifying patients with different risk of evolution. 2) if there is a correlation between PU and different prognostic factors, such as mutational state, absolute lymphocyte count, CD38 positivity, age 3) if patients with Rai 0 disease and with PU are prognostically similar to Rai 1. Between 1999 and 2011, 189 patients with Rai 0 or Rai 1 CLL had a ultrasonography (US) performed at diagnosis. Lymph nodes more than 10 mm in diameter were considered abnormal. In 137 of them mutational status had been determined. Fluorescence in situ hybridization (FISH) analysis for 11,12, 13 17 was not generally performed at diagnosis but only before the beginning of treatment. The Fisher’s exact or t tests were used to analyze the association between the presence of an abnormal US and the clinical characteristics. Survival time and time to progression (TTP) were analyzed using the Kaplan-Meier method and curves were compared by means of the log-rank test. Results Mean age was 63.2 years (range 41-85). Patients had Rai stage 0 (n=130) disease or Rai stage 1 (n=59). Median absolute lymphocyte count was 12.2 x 10^9/L. Overall, PU were present in 40/189 (21.2%) patients, with dimensions of lymph nodes up to 120 mm. PU were significantly more frequent in patients with Rai 1 disease (23/59 – 39%) than in Rai 0 (17/130 – 13.1%) disease (p 20 x 10^9/L (15/47 – 31.9%) than in patients with absolute lymphocyte count at diagnosis < 20 x 10^9/L (25/142 – 17.6%) (p=0.03). No significant differences were present in age, hemoglobin concentration, absolute neutrophil count, platelet count or CD38 positivity. When all patients are considered, patients with PU had a shorter time to progression when compared to patients without PU (median 56 months vs not reached - p The presence of PU has a significant prognostic significance for TTP in patients with unmutated disease with median TTP of 68 vs. 25 months (p=0.007). Among patients with mutated disease, median TTP were 112 for patients with PU and not reached for patients without PU (p=n.s.). No differences in overall survival could be shown. Conclusions The presence of PU at diagnosis can identify a subgroup of Rai 0 CLL with shorter TTP; this confirms results reported with computed tomography. Patients with Rai 0 disease and PU had an intermediate but significantly different TTP between Rai 0 without PU and Rai 1. PU retains its importance also when only unmutated patients are considered; among mutated patients, a statistically significant difference could not be shown , also due to the low number of events in these patients. An ultrasonography performed at diagnosis appears to be useful in low-risk CLL patients: it is a non-toxic imaging technique that can identify subgroups of low-risk patients; in patients with PU at diagnosis, it can be repeated in follow-up to evidence progressive abdominal disease. Disclosures: No relevant conflicts of interest to declare.

Abstract 2877 The Anaplastic Lymphoma Kinase (ALK) gene is fused to several partner genes (mainly NPM) in the majority of Anaplastic Large Cell lymphoma (ALCL) patients (pts). Deregulated ALK tyrosine kinase activity represents the driver alteration in this disease, through the phosphorylation of proteins belonging to signal transduction pathways involved in cellular proliferation, apoptosis and differentiation. Although ALK+ ALCL pts are responsive to cytotoxic drugs, relapses occur frequently and bear a dismal prognosis. Crizotinib is a competitive small-molecule inhibitor of the ALK and c-Met/HGFR receptor tyrosine kinases with cellular IC50 values in NPM-ALK expressing cells comprised between 24 and 60 nM. A dose of 250 mg BID orally was previously established as the recommended dose in a phase I study. We report here on the safety and activity profile of crizotinib in two ALK+ ALCL pts resistant to cytotoxic therapy who received crizotinib 250 mg BID as part of a compassionate use named patient protocol. No steroids or drugs with antineoplastic activity were allowed; potent CYP3A4 inhibitors/inducers were also excluded. Pt # 1 is a 26 year old female who received 7 cycles of CHOP-15 with a partial response that lasted only 1 month. Subsequently she was treated with the DHAP and ICE regimens in an attempt to collect stem cells for an autologous BMT. However, even with these two salvage regimens, the pts relapsed within 2–3 weeks after each one. Pretreatment evaluation included fever (>38 C), cervical and inguinal adenopathies, positive PET and CT scans of para-aortic and iliac adenopathies; a bone marrow (BM) aspirate showed 3% of cells with positivity using an ALK break-apart probe by FISH. Fever disappeared within 48 hours after starting crizotinib; by day 7 all superficial adenopathies were no longer present. PET, CT and BM aspirate performed at day 28 days showed regression of previous lesions persisting so far for 2 months. Side effects included transient ocular flashes and grade I LFT elevation. Pt # 2 is a 21 year old male diagnosed with ALK+ ALCL in August 2009. The pt was treated with 6 cycles of CHOP obtaining a CR that was lost in February 2010. The pt underwent re-induction/mobilization chemotherapy with MAD and received an Autologous Bone Marrow Transplantation in May 2010 after conditioning with the BEAM regimen; he obtained a PR which was lost again after 1 month. Pretreatment evaluation included fever (>39 C, requiring 60 mg prednisone and 3 g paracetamol daily), axillary and inguinal adenopathies, positive PET and CT scans of all internal nodal stations; BM showed 8% of positive cells using an ALK break-apart probe. Within 8 days of treatment constitutional symptoms subsided, all superficial adenopathies disappeared and PET scan shows complete regression of all lesions. Adverse events reported so far include grade I dizziness. Longer follow-up data along with results from a third ALCL patient will be presented at the meeting. Disclosures: No relevant conflicts of interest to declare.

Abstract 2489 Introduction: Epigenetic aberrations play an important role in the development and progression of Multiple Myeloma (MM). 5-aza-2-deoxycytidine (5Aza-dC) and Trichostatin A (TSA) have been studied in reactivating the expression of epigenetically-silenced genes. IGFBP3 gene is a member of the insulin-like growth factor binding protein (IGFBP) family and can regulate cell growth and death by the ability to bind insulin-like growth factors (IGFs) as well as its IGF-independent effects involving binding to other molecules. Several in vitro, in vivo studies as well as clinical evidence point to IGFBP-3 as an anti-cancer molecule. In our study we analyzed global changes in gene expression profiles of MM cell lines, responding to 5Aza-dC and TSA and we evaluated the IGFBP3 expression in three myeloma cell lines and in samples from myeloma patients. Methods: Human MM cell lines U266 and H929 were treated either with 0.5 micromol/L 5Aza-dC for 7 days or with 100 ng/mL TSA for 24 h or with the combination of 0.5 micromol/L 5Aza-dC for 7 days and 100 ng/mL TSA for additional 24 h. Control cells received no drug treatment. Applied Biosystems microarray platform ABI 1300 was used for carrying out microarray profiling and analysis. To classify up-regulated genes into functional categories the PANTHER Classification System was used (http://www.pantherdb.org). Stained or unstained bone marrow slides were collected from archival samples of 179 myeloma patients. For validation of microarray results, real-time reverse transcription-PCR (RT-PCR) was performed using Taqman Gene Expression Assays (Applied Biosystems). Results: After treatment with 5Aza-dC there was up regulation of gene expression in 698 genes in H929 cell line and 258 genes in U266 cell line. After treatment with TSA 719 genes were up regulated in H929 cell line and 742 genes in U266 cell line. The exposure to the combination of 5Aza-dC/TSA resulted in up-regulation of 921 genes in H929 cell line and 615 genes in U266 cell line. By using Panther classification system we classified up-regulated genes into functional categories and we identified several 5Aza-dC or TSA up-regulated genes that are involved in important cancer-related pathways including cell cycle, apoptosis, cell adhesion, oncogenesis and cell metabolism, including DNA repair and nucleosome assembly. Between these genes we particularly found interesting the expression changes of IGFBP-3 which was up regulated after treatment with 5-azacitidine in U266 cell line (level of induced expression was 5,16). The microarray data were validated in 3 MM cell lines and 179 patients samples by analysis of relative changes in IGFBP3 expression through ΔΔCt method. We found that the expression levels of IGFBP3 were significantly lower in U266 and RPMI myeloma cell lines, but not in H929 cell line and interestingly levels were lower in 54 percent of patients (Fig 1). It has been demonstrated decreased IGFBP-3 expression is associated with cancer progression and in our study we have shown that the down-regulation of this gene may be involved also in myeloma pathogenesis and mediate progression events, hence levels of IGFBP3 may be considered as a biomarker for disease staging. From a therapeutic point of view, up-regulation of IGFBP3 might be considered as target therapeutic strategy for monoclonal gammopathies/ smouldering Myelomas at high risk of progression to active myeloma. Disclosures: No relevant conflicts of interest to declare.

The course of early stage CLL patients may be very different with patients who never need therapy and other who need therapy at different times. The presence or absence of somatic mutations in the immunoglobulin heavy-chain gene of the CLL cell (mutational status) was recently identified as one of the most predictive factors for the time from diagnosis to initial treatment. CD-38 and ZAP-70 were also shown to have a similar prognostic value and they were sometimes considerate as a “surrogate” markers of mutational state. This study was aimed to evaluate the prognostic impact of different prognostic factors on time from diagnosis to initial treatment in this subgroup of CLL patients. We studied 127 patients (71 M; 56 F); median age was 64,3 (range 42 – 84). All they had a stage A CLL at diagnosis. When Rai stage was considered, 83 had stage 0, 32 stage I and 12 patients stage II. Median follow-up was 65 months (range 6 – 232 months). Absolute lymphocyte count was: median 19 cells × 10^9/l (range 2,5 – 99). Median hemoglobin was 13,82 g/dL (range 11,3 g/dL – 17,5 g/dL). Median platelet count was 209 × 109/L (range 102 × 109/L e 533 × 109/L.). Patients were treated when symptomatic or progressive disease developed, according to National Cancer Institute Working Group criteria. The following cut-off values were used: CD38 >20%; ZAP-70 > 20%; VH unmutated: >98% homology with germ-line sequence. 26% of patients were CD38 positive, 28% were ZAP-20 positive; 24% patients were VH unmutated. 39/127 patients included in the study had received one or more chemotherapy regimens. First line therapy was chlorambucil in 28 patients, fludarabine in six, different therapies (cyclophosphamyde, prednisone, rituximab) in 5. Median interval between diagnosis and initial therapy was 30 months (range 1–96). 22 % of Rai 0 pts, 44 % of Rai 1 pts 50% of Rai 2 pts were treated. 65% of ZAP-70 positive were treated vs 18% of ZAP-70 negative. 55% of unmutated were treated vs 18% of mutated pts. 42% of CD-38 positive were treated vs 26% of CD-38 negative. When the interval from diagnosis to therapy was analyzed with a Kaplan-Meier survival curve (see figures), mutational status and ZAP-70 positivity were the most significant prognostic factors. Median treatment-free time was 35 months for ZAP-70 negative patients vs. 190 months for ZAP-70 positive patients (p= 0,001). Median treatment-free time was 40 months for unmutated vs. 190 months for mutated patients (p= 0,002). When CD-38 was analyzed, a borderline significant value was obtained (p=.0.08) with median treatment-free interval of 70 months in CD-38 positive patients vs. 98 months in CD-38 negative patients. Absolute lymphocyte count (with a cut-off at 15 cells × 10^9/l) also showed a significant impact on the need of treatment. Time from diagnosis to initial treatment and IgVH omology Time from diagnosis to initial treatment and IgVH omology Time from diagnosis to initial therapy and ZAP 70 Time from diagnosis to initial therapy and ZAP 70