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  • 1
    In: Blood, American Society of Hematology, Vol. 124, No. 21 ( 2014-12-06), p. 3043-3043
    Abstract: Introduction: Phosphoinositide-3-kinases (PI3Ks) are pivotal in various cellular functions including cell proliferation and survival, cell differentiation, intracellular trafficking and immunity. The delta (δ) and gamma (γ) isoforms of PI3K are highly expressed in cells of hematopoietic origin, and often dysregulated in various hematologic malignancies. Because these isoforms contribute to the development, maintenance, transformation, and proliferation of immune cells, dual targeting of PI3K δ and γ represents a promising approach in the treatment of lymphomas. RP6530 is a novel, highly specific dual PI3K δ/γ inhibitor with nanomolar inhibitory potency at the enzyme and cellular level. Besides, RP6530 was effective in inhibiting Akt phosphorylation and inducing apoptosis in various lymphoma and leukemic cell lines. Herein we present preliminary results of a Phase I, first in human, open label study of an oral PI3K δ/ γ inhibitor, RP6530. (NCT02017613). Methods: The dose escalation will determine the maximum tolerated dose (MTD) of RP6530 using a standard 3+3 design. Patients (pts) with a confirmed diagnosis of B-cell non-Hodgkin lymphoma, peripheral T-cell lymphoma, chronic lymphocytic leukemia, Acute lymphoblastic leukemia (CLL), Primary central nervous system lymphomas or Multiple myeloma who have at least one prior therapy are eligible. Additional eligibility criteria include ECOG performance status ≤ 2, and measurable/evaluable disease with a life expectancy of at least 12 weeks. Primary endpoints are safety and pharmacokinetic (PK) parameters; secondary endpoints include pharmacodynamic and drug activity (overall and complete response rates). Correlative biomarker samples including quantitative/qualitative measurements of cytokines, chemokines and aberrations indicative of PI3K function and RP6530 efficacy will be analyzed. RP6530 is given orally twice daily in 28-day cycles until disease progression, unacceptable toxicity, or withdrawal from treatment. The study is designed to enroll up to 30 pts in the dose-escalation phase with up to an additional 42 pts in the cohort expansion phase. Efficacy evaluations are planned every 8 weeks. Adverse events (AE) are assessed using the CTCAE v4.0/ IWCLL guidelines as applicable. Results: Nine pts were enrolled to date across 3 dose levels: BID 25mg, 50mg and 100mg. Five pts were males; ECOG score was 0/1/2 in 5/1/3 pts, respectively, with mean age of 74 yrs (range: 54-82). Pts had median 5 (range: 1-11) prior treatment regimens, and 6 were refractory to prior treatments. Lymphoma categories included DLBCL (2 pts), Mantle Cell Lymphoma (2 pts), follicular lymphoma (1 pt), Marginal Zone Lymphoma (1 pt); and CLL/SLL (2 pts); one pt had multiple myeloma. All nine pts are evaluable for DLT assessment. Of the 9 evaluable pts, 6 are currently on study; 1 patient discontinued treatment due to disease progression. Pts tolerated the treatment well. To date, there have been no DLTs. One pt experienced G4 neutropenia that was unrelated to RP6530. No other G3/4 related hematologic or non-hematologic toxicities were observed. Of the six pts who completed 2 cycles of treatment (8 wks) at 50 mg daily dosing or less, 5 showed stable disease while 1 had disease progression. Three pts did not reach the first response assessment. Mean PK parameters determined on Day 1 of Cycle 1(C1D1) are: median Tmax of 1 hrs (range 0.5-2.0hrs), harmonic mean t1/2 of 2 (± 0.47) hr, and CL/F of 39.55 (± 19.3) L/hr. A linear relationship exists between dose and both AUC (r2 = 0.97) and Cmax (r2 = 0.97). The average accumulation index represented by Cmin on Cycle 2 day 1 is 1.12 (± 0.1). PK data from the first 3 cohorts on C1D1 is summarized below. Table 1.Dose25 mg (n=3)50 mg (n=3)100 mg (n=3)Cmax (µg/mL)0.356 (± 0.08)0.563 (± 0.12)1.329 (± 0.55)AUC (µg*hr/mL)0.775 (± 0.32)1.619 (± 0.67)2.482 (± 1.18) Conclusions: To date, RP6530 has been well tolerated in pts with heavily pre-treated relapsed/refractory hematologic malignancies. There were no DLTs and toxicities were minimal. Enrollment continues at higher dose cohorts. Updated safety, efficacy, PK, and PD data will be presented. Disclosures Scarfò: Rhizen Pharmaceuticals SA: Research Funding. Barde:Rhizen Pharmaceutical SA: Employment. Fazi:Rhizen Pharmaceuticals SA: Research Funding. Kumar:Rhizen Pharmaceuticals SA: Employment. Viswanadha:Incozen: Employment. Vakkalanka:Rhizen Pharmaceuticals SA: Employment, Equity Ownership. Ghia:Rhizen Pharmaceuticals SA: Research Funding. Ferreri:Rhizen Pharmaceuticals SA: Research Funding.
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    Publisher: American Society of Hematology
    Publication Date: 2014
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  • 2
    In: Blood, American Society of Hematology, Vol. 120, No. 21 ( 2012-11-16), p. 2883-2883
    Abstract: Abstract 2883 CLL-like monoclonal B-cell lymphocytosis (MBL) shares common immunophenotypic features and cytogenetic abnormalities with CLL and is generally perceived as its premalignant state. The World Health Organization has set a consensus cut-off of 5×109/L circulating B cells to discriminate between what constitutes ‘disease’ and what not. However, the clonal size within MBL is extremely variable. High-count (HC), clinical MBL is associated with absolute lymphocytosis and progresses to CLL requiring treatment at a rate of 1–2% per year, whereas low-count (LC) MBL is found in the general population through high-sensitivity techniques and carries a risk of progression that is limited if any. Given the high frequency of CLL-like MBL in the general population, it is important to understand the underlying mechanisms and also identify biological markers endowing malignant potential that may distinguish between the different forms. To this end, we performed a detailed immunogenetic profiling of 334 CLL-like MBL cases (78 LC and 256 HC) for a total of 355 productive VDJ rearrangements (including double rearrangements), 91 from LC MBL and 264 from HC MBL. We also compared the immunoglobulin (IG) gene repertoires of MBL to 544 CLL Rai Stage 0 (CLL-0) that were part of an IG sequence dataset of 7424 CLL cases previously analyzed by our group. LC and HC MBL had distinct IG gene repertoires, with over-representation of the IGHV1–69 and IGHV4–34 genes in HC and the IGHV4–59/61 genes in LC MBL, respectively (p 〈 0.001). The HC MBL repertoire exhibited clear similarities to CLL-0 in terms of IGHV gene usage (similar frequencies of IGHV1–69 and IGHV4–34). Regarding somatic hypermutation, no differences were identified between LC MBL versus HC MBL versus CLL-0, in that the frequency of mutated rearrangements ( 〈 98% identity to the germline) was overall similar (LC MBL: 72.5%, HC MBL: 76.1%, CLL-0: 75%). In this respect, all the aforementioned subgroups differed significantly (p 〈 0.001) from the frequency previously reported by us in CLL where only 55% of rearrangements carried mutated IGHV genes. We finally analyzed the expression of stereotyped B cell receptor (BcR) IGs, identified through a cluster analysis of the MBL sequences together with all CLL sequences from our cohort and 5494 non-CLL IG sequences retrieved from public databases. Overall, only 6/91 (5.5%) LC MBL rearrangements could be clustered with other sequences in subsets with stereotyped BcRs. Two of these six LC MBL cases were clustered together with IG sequences from various entities, including CLL, other lymphomas and autoimmune diseases; thus, they were considered to carry ‘public’ BcR stereotypes. In contrast, HC MBL showed a significantly (p=0.0002) higher frequency of ‘CLL-specific’ BcR stereotypes versus LC MBL, with 60/264 (22.7%) HC MBL cases carrying stereotyped VH CDR3s. This frequency was comparable to the one observed in CLL-0 (20.2%). Notably, a gradation was observed in the frequency of BcR IG stereotypy depending on the absolute count of CLL-like cells, starting with 5.5% in LC MBL, raising to 22.7–20.2% in in HC MBL/CLL-0 and, finally, peaking at 30.4% in the entire CLL cohort as previously reported. Altogether, these findings suggest that rather than a true premalignant condition, LC MBL may merely reflect immune senescence or result from persistent antigen stimulation. On the other hand, HC MBL appears to be a continuum with Rai stage 0 in the evolution to clinically overt CLL, being maybe one step behind where it requires either additional genetic hits or simply extra time to cross the numerical border that discriminates it from CLL. Hence, the identification of molecular genetic markers that may predict progression of HC MBL/CLL-0 into full-fledged CLL is strongly warranted. Disclosures: Shanafelt: Genentech: Research Funding; GlaxoSmith Klein: Research Funding; Teva/Cephalon: Research Funding; Celgene: Research Funding.
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    Publication Date: 2012
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  • 3
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    American Society of Hematology ; 2014
    In:  Blood Vol. 124, No. 21 ( 2014-12-06), p. 4677-4677
    In: Blood, American Society of Hematology, Vol. 124, No. 21 ( 2014-12-06), p. 4677-4677
    Abstract: B-Cell Receptor (BCR) triggering and responsiveness play a crucial role in the survival and expansion of Chronic Lymphocytic Leukemia (CLL) clones. In the recent past, several groups including ours have investigated the activation status of the signaling pathways originating from the leukemic BCR. Specifically we found that around 50% of CLL patients display a biochemical signature characterized by constitutive phosphorylation of ERK1/2 (pERK(+)) and constitutive nuclear translocation of NF-ATc1. These cases are unable to respond in vitro to BcR stimulation and are resistant to spontaneous apoptosis, thus resembling B lymphocytes previously anergized in vivo. Similar biochemical and functional features have been recently demonstrated in B leukemic cells persisting in the blood in patients treated with the BTK inhibitor, Ibrutinib, thereby making anergy an attractive target on the way to obtain eradication of the disease. CLL-associated B cell anergy can be specifically targeted by using different MAPK-inhibitors that have been shown to induce apoptosis selectively in the group of pERK(+) CLL. These data suggested that MAPK signalling can be efficiently inhibited in CLL for therapeutic purpose and that the phosphorylation status of ERK1/2 may represent a reliable biomarker to predict and monitor treatment response. However, even if the tested compounds were shown to be extremely efficient in inhibiting ERK1/2 phosphorylation in vitro, a lack of clinical activity was reported for many of them when tested in patients, mostly with solid tumors. In the present work, we used Trametinib, a specific MEK1/2 inhibitor, recently approved as a single-agent for the treatment of V600E mutated metastatic melanoma, and we investigated, at preclinical level, its activity in both primary CLL samples and a xenograft leukemic mouse model. Trametinib treatment completely inhibited constitutive ERK1/2 phosphorylation in 10 pERK1/2(+) samples at 3uM after 30 minutes treatment. Additionally, in 23 patients Trametinib treatment for 48 hours reduced cell viability in the cells from all 12 pERK1/2(+) patients (28,2% ± 3,5 mean survival) tested as compared to those from the pERK(-) group (11 cases, 58,1% ± 3,8 mean survival, p 〈 0,0001). To strengthen our in vitro data, we evaluated the effect of Trametinib administration in the xenograft Rag2-/-gc-/- mouse model subcutaneously transplanted with the CLL cell line MEC1, characterized by specific features of anergy. Mice were subcutaneously injected with 10x106 cells and then challenged with Trametinib (oral gavage with 1mg/kg or with vehicle alone) starting from day 21 after tumour injection for 14 days. The effect of the inhibitor was monitored by tumour volume growth. Trametinb administration delayed tumour growth (p 〈 0.05 starting at days 27) and inhibited leukemic cell dissemination in the peripheral blood, peritoneal cavity and bone marrow. In summary, our data further support the idea that blocking anergic pathways may be highly effective not only in vitro but also in vivo with potential clinical implications at least in the subset of patients whose cells are characterized by anergic features, including those with persistent lymphocytosis when treated with Ibrutinib. The preclinical efficacy shown by Trametinib, a drug already approved for clinical use, warrants the implementation of controlled studies in CLL patients. Disclosures No relevant conflicts of interest to declare.
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    Publication Date: 2014
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  • 4
    In: Blood, American Society of Hematology, Vol. 120, No. 21 ( 2012-11-16), p. 928-928
    Abstract: Abstract 928 B-cell receptor (BCR) signaling and cytoskeletal activation represent critical steps in the pathogenesis of Chronic Lymphocytic Leukemia (CLL). We previously demonstrated that Hematopoietic cell specific Lyn substrate 1 (HS1) i) is a potential prognostic marker as CLL patients whose leukemic cells carry hypo-phosphorylated (hypo-p) HS1 have a better prognosis than patients with the hyper-phosphorylated (hyper-p) form; ii) is a central interactor of several cytoskeletal components and iii) has a profound effect on the development and progression of CLL in the Eμ-TCL1 transgenic mouse suggesting that the hyper-phosphorylation of the molecule may be responsible of HS1 inactivation rather than its activation. To better define the role of HS1 phosphorylation in CLL cell biology we dissected the BCR signaling pathway in cells with differential phosphorylation of the HS1 protein. Taking advantage of the CLL cell line MEC1 where we silenced the expression of HS1, we observed that the phosphorylation status of several BCR signalling molecules, including LYN kinase, is reduced in the absence of HS1. A similar pattern of modifications was confirmed in primary cells from 62 patients with different phosphorylation status of HS1 (Figure A n=35 HS1hypo-p vs n=27 HS1hyper-p, p=0,01), thereby identifying a distinct phospho-signature associated to HS1. LYN phosphorylation correlates with clinical parameters as phosphoLYN+ patients showed significantly increased (Figure B n=28 phosphoLYN+ vs n=28 phosphoLYN− p=0,0002) Progression-free survival and Treatment-free survival (Figure C n=27 phosphoLYN+ vs n=26 phosphoLYN− p=0,0002) as compared to phosphoLYN−patients. We further investigated the relationship between HS1 and LYN phosphorylations and showed that LYN kinase activation- Tyrosine (Y)396 phosphorylation- is associated with the phosphorylation of the active site Y397 on HS1 protein (Spearman correlation n=40, p 〈 0,0001). Patients may thus be categorized into two subgroups based on the phosphorylation status of the two molecules as “active-HS1” - HS1 hypo-p/phosphoLYN+ and “inactive-HS1” - HS1 hyper-p/phosphoLYN−-. These different patterns correlated with distinct cytoskeletal functionality in terms of migration (active-HS1 n=12 vs inactive-HS1 n=9, p= 0,009), spontaneous adhesion (active-HS1 n=12 vs inactive-HS1 n=9, p=0,03), adhesion to an HS5 stromal cell layer (active-HS1 n=9 vs inactive-HS1 n=10 p=0,006) and F-actin polymerization (active-HS1 n=12 vs inactive-HS1 n=11, p=0,001). Targeting the LYN/HS1 axis in vitro with the tyrosine kinase inhibitor Dasatinib significantly affected primary CLL cell viability with a direct correlation with basal LYN phosphorylation (Sperman correlation n=32, p=0,04) and interfered with cytoskeleton activity, with a preference for patients carrying the “active-HS1” signature. Accordingly, 100nM Dasatinib markedly reduced migration of active-HS1 samples (active-HS1 n=10, p=0,003 vs inactive-HS1 n=7, p 〉 0,05), with no significant effect on inactive-HS1 samples. F-actin polymerization (active-HS1 n=9 p=0,003, vs inactive-HS1 n=8 p=0,01) was reduced in both groups by Dasatinib treatment, while spontaneous (active-HS1 n=7, p=0,03 vs inactive-HS1 p 〉 0,05) and HS5-mediated cell adhesion (active-HS1 n=8, p=0,03 vs inactive-HS1 n=8 p 〉 0,05) were affected by the treatment only in the active-HS1 group. In the adoptive transfer mouse model based on the EmTCL1 transgenic mouse, a 4-week Dasatinib treatment reduced the percentage of CD19+CD5+Igk+ CLL cells in the blood as soon as one week after treatment initiation and throughout the whole treatment period (p(Day6)=0,007, p(Day13)=0,005, p(Day20)=0,004, p(day of killing)=0,01). At sacrifice, a significant reduction in the absolute number of leukemic cells in the spleen (p=0,05), bone marrow (p=0,03) and lymph nodes (p=0,04) was observed in treated mice as compared to controls. Consistent with the biochemical action of Dasatinib, significant reduction in SRC-Y416 phosphorylation was observed after intracellular staining of leukemic B cells (p=0,04) at the end of treatment. These observations suggest that the phosphorylations status of LYN and HS1 as a biological indicator of respectively distinct signaling pathway and cytoskeletal-related features that can be selectively targeted for therapeutic intervention in a sizable fraction of CLL patients. Disclosures: No relevant conflicts of interest to declare.
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    Publication Date: 2012
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  • 5
    In: Blood, American Society of Hematology, Vol. 132, No. Supplement 1 ( 2018-11-29), p. 3147-3147
    Abstract: Introduction. Observational, real-life studies are relevant to understand whether data derived from prospective controlled trials (CTs) are reproducible in the day-to-day clinical practice. Within a named patient program (NPP), free and early access to ibrutinib was made available for the treatment of relapsed/refractory (R/R) patients with chronic lymphocytic leukemia (CLL) until this agent was approved in Italy. To define the efficacy and toxicity profile of patients treated with ibrutinib in this real-life setting, the GIMEMA (Gruppo Italiano Malattie EMatologiche dell'Adulto) group carried out a retrospective analysis on the outcome of R/R patients with CLL who received ibrutinib in the NPP. Methods. Between April 2014 and January 2015, 216 R/R patients with CLL managed at 20 centers in Italy were included in the NPP. Patients were required to have R/R disease with disease progression within 24 months after prior chemo-immunotherapy. All patients received ibrutinib at the standard dose of 420 mg daily, continuously until disease progression or unacceptable toxicity. The period of observation included the duration of the NPP and was extended up to January 2016 for patients still on treatment with the commercial drug. Clinical data were reported retrospectively by the treating physicians using the Research Electronic Data Capture (REDCap) system. Results. The median age of patients was 58.3 years (range 27.5-81); 89% of patients were in Binet stage B-C. The median number of prior treatments was 3 (range 1-14). Thirty-seven % of patients was refractory to prior treatment. Deletion 17p and/or TP53 mutations were found in 54% of patients and deletion 11q in 11.6%. Seventy-eight % of patients had an unmutated IGHV gene profile. Prior atrial fibrillation (AF) was reported in 13 cases (6%), while 7 patients with AF (3.3%) were on anti-arrythmic treatment. Hypertension was recorded in 76 cases (35.2%). The median follow-up of patients was 24 months (range, 1-24 months. A response to ibrutinib was observed in 172 patients (79.6%) with a clinical CR/CRi in 34 (15.7%) and a PR/PR-L in 138 (63.9%). Similar response rates were observed in patients with an unmutated IGHV gene status (82.1%) and in those with deletion 17p/TP53 mutations (79.6%). The progression-free survival (PFS) and overall survival (OS) at 24 months were 64.6% (95%CI: 58.0-71.9) and 72.7% (95%CI: 66.5-79.4), respectively. No differences in PFS and OS were observed according to the IGHV mutational status (IGHV unmutated vs mutated: PFS, 65.2% vs 61.0%; p=0.7; OS, 65.2% vs 72.0%, p=0.6) and the presence of TP53 aberrations (TP53 aberrations, present vs absent: PFS, 64.8% vs 64.1%; p=0.6; OS, 69.8% vs 72.7%; p=0.8). Forty-eight patients (22.2%) discontinued ibrutinib within 12 months and 22 (10.2%) within 12-24 months from the start of ibrutinib. Progressive disease and Richter syndrome were the most common reasons for discontinuation that accounted for 16.2% (35 patients) and 1.8% (4 patients) of cases, respectively, and occurred after a median of 17 months from the start of ibrutinib. Treatment discontinuations due to adverse events (AEs) were recorded in 25 patients (11.6%) after a median time of 6 months from the start of treatment and included infections/febrile events in 7 cases, bleeding events in 3 (intracranial hemorrhage 1), sudden death in 3, acute myocardial infarction in 1, ischemic stroke in 2, second malignancy in 3, diarrhea in 1. AF occurred during treatment in 14 (6.5%) patients and was the reason of ibrutinib discontinuation in 2. AEs leading to discontinuation was not specified in 3 cases. Other reasons for ibrutinib discontinuation in 6 (2.8%) patients were ASCT in 4, unplanned surgery in 1, unknown in 1. Survival probability at 12 months from treatment discontinuation due to AEs or DP/RS was 38.2 and 37.2 months respectively (p= 0.6). Conclusions. The results of this real-life study show that in unselected patients with R/R CLL the clinical activity of ibrutinib was comparable to that reported in CTs. However, a third of patients discontinued ibrutinib within 24 months from the start of treatment. An earlier introduction of ibrutinib in the treatment approach of R/R patients, a careful surveillance and management of toxicities will optimise the clinical benefits of ibrutinib in CLL patients treated in the clinical practice. Disclosures Mauro: Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Shire: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Zinzani:TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astra Zeneca: Speakers Bureau; MSD: Honoraria, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SERVIER: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees. Cortelezzi:novartis: Consultancy; roche: Consultancy; abbvie: Consultancy; janssen: Consultancy. Carlo-Stella:AstraZeneca: Speakers Bureau; Bristol-Myers Squibb: Speakers Bureau; Janssen: Speakers Bureau; Sanofi: Consultancy; ADC Therapeutics: Research Funding, Speakers Bureau; Boehringher Ingelheim Italia: Consultancy; Genenta Science: Speakers Bureau; Rhizen Pharmaceuticals: Research Funding; Amgen: Speakers Bureau; MSD Italia: Speakers Bureau. Molica:Roche: Other: Advisory board; Gilead: Other: Advisory board; Jansen: Other: Advisory board; AbbVie: Other: Advisory board. Coscia:Janssen, Karyopharm: Research Funding; Abbvie, Gilead, Shire: Honoraria, Membership on an entity's Board of Directors or advisory committees. Zaja:Janssen: Honoraria; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Amgen: Honoraria; Takeda: Honoraria; Sandoz: Honoraria; Abbvie: Honoraria. Gaidano:Roche: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Morphosys: Honoraria; AbbVie: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Gobbi:Ariad: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; Amgen: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; Pfister: Membership on an entity's Board of Directors or advisory committees. Cuneo:janssen: Other: advisory board, Speakers Bureau; Gilead: Other: advisory board, Speakers Bureau; Abbvie: Other: advisory board, Speakers Bureau; Roche: Other: advisory board, Speakers Bureau. Foà:JANSSEN: Other: ADVISORY BOARD, Speakers Bureau; NOVARTIS: Speakers Bureau; ROCHE: Other: ADVISORY BOARD, Speakers Bureau; ABBVIE: Other: ADVISORY BOARD, Speakers Bureau; AMGEN: Other: ADVISORY BOARD; CELTRION: Other: ADVISORY BOARD; GILEAD: Speakers Bureau; CELGENE: Other: ADVISORY BOARD, Speakers Bureau; INCYTE: Other: ADVISORY BOARD.
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    ISSN: 0006-4971 , 1528-0020
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    Publisher: American Society of Hematology
    Publication Date: 2018
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  • 6
    In: Blood, American Society of Hematology, Vol. 126, No. 23 ( 2015-12-03), p. 5263-5263
    Abstract: The IGHV4-34 gene is very frequent (~10%) in the B cell receptor immunoglobulin (BcR IG) gene repertoire of chronic lymphocytic leukemia (CLL). Over 30% of IGHV4-34 CLL cases can be assigned to different subsets with stereotyped BcR IG. The largest is subset #4 which represents ~1% of all CLL and ~10% of IGHV4-34 CLL and is considered a prototype for indolent disease. The BcR IG of a great majority (~85%) of IGHV4-34 CLL cases carry a significant load of somatic hypermutation (SHM), often with distinctive SHM patterns. This holds especially true for stereotyped subsets and is suggestive of particular modes of interactions with the selecting antigen(s). In detail, subsets #4 and #16, both involving IgG-switched cases (IgG-CLL), exhibit the greatest sequence similarity in SHM profiles, whereas they differ in this respect from IgM/D subsets #29 and #201. Prompted by these observations, here we explored the extent that these subset-biased SHM profiles in different IGHV4-34 stereotyped subsets were reflected in distinct demographics, clinical presentation, genomic aberrations and outcomes. Within a multi-institutional series of 20,331 CLL patients, 1790 (8.8%) expressed IGHV4-34 BcR IG. Following established bioinformatics approaches for the identification of BcR IG stereotypy, 573/1790 IGHV4-34 CLL cases (32%) were assigned to stereotyped subsets; of these, 340 cases (19% of all IGHV4-34 CLL and 60% of stereotyped IGHV4-34 cases) belonged to subsets #4, #16, #29 and #201, all concerning IGHV-mutated CLL (M-CLL). Clinicobiological information was available for 275/340 patients: #4, n=150; #16, n=44; #29, n=39; and #201, n=42. Comparisons between subsets revealed no differences in gender and age distribution. Interestingly, however, 36-43% of each subset cases were young for CLL (defined as patients aged ≤55 years), which is higher compared to general CLL cohorts, where young patients generally account for ~25% of cases. In contrast, significant differences were identified between subsets regarding: (i) disease stage at diagnosis, with 〉 90% of IgG subsets #4 and #16 diagnosed at Binet stage A versus 83% in subset #201 and 74% in subset #29 (p=0.029); (ii) CD38 expression, ranging from 1% in subset #4 to 10% in subset #201 (p=0.013); (iii) the distribution of del(13q), peaking at a remarkable 92% in subset #29 versus only 37% in subset #16 (p 〈 0.0001). Regarding other genomic aberrations, they were either absent (NOTCH1 mutations) or rare (SF3B1 mutations, trisomy 12, del(11q), TP53 aberrations due to either del(17p) and/or TP53 mutations). The sole exception concerned a high frequency (14%) of TP53 aberrations in subset #29 (p 〈 0.05 compared with the other subsets), which is notable for M-CLL cases in general. Time to first treatment (TTFT) could be analyzed in 228 cases. IgG subsets #4 and #16 had significantly (p=0.036) longer TTFT (median TTFT: not yet reached) compared to the IgM/D subsets #29 and #201 (median TTFT: 11 and 12 years, respectively). In conclusion, we have identified distinct clinicobiological profiles for different stereotyped IGHV4-34 M-CLL subsets, highlighting subsets #4 and #16 as particularly indolent, which is important for both medical and social reasons, especially considering that a significant proportion of patients in these subsets are diagnosed at younger ages. Our findings support the notion that BcR IG stereotypy refines prognostication in CLL, superseding the crude immunogenetic distinction based on SHM load only. Additionally, the observed heterogeneity suggests that not all M-CLL are equal, prompting further research into the underlying biological background with the ultimate aim of tailored patient management. Disclosures Tausch: Gilead: Other: Travel support. Shanafelt:Glaxo-Smith_Kline: Research Funding; Genentech: Research Funding; Celgene: Research Funding; Polyphenon E Int'l: Research Funding; Hospira: Research Funding; Janssen: Research Funding; Pharmactckucs: Research Funding; Cephalon: Research Funding. Niemann:Gilead: Consultancy; Janssen: Consultancy; Roche: Consultancy; Novartis: Other: Travel grant. Langerak:InVivoScribe: Patents & Royalties: Licensing of IP and Patent on BIOMED-2-based methods for PCR-based Clonality Diagnostics.; DAKO: Patents & Royalties: Licensing of IP and Patent on Split-Signal FISH. Royalties for Dept. of Immunology, Erasmus MC, Rotterdam, NL; Roche: Other: Lab services in the field of MRD diagnostics provided by Dept of Immunology, Erasmus MC (Rotterdam). Hallek:Celgene: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; AbbVie: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Roche: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Boehringher Ingelheim: Honoraria, Other: Speakers Bureau and/or Advisory Boards; Pharmacyclics: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Mundipharma: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Janssen: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Gilead: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding. Ghia:Janssen Pharmaceuticals: Research Funding.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2015
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  • 7
    In: Blood, American Society of Hematology, Vol. 134, No. Supplement_1 ( 2019-11-13), p. 170-170
    Abstract: One of the most common secondary resistance mechanisms to ibrutinib (IBR, a first-generation, irreversible Bruton's tyrosine kinase [BTK] inhibitor) in CLL is the development of mutations in BTK involving Cys481, leading to impaired drug binding (Woyach et al, NEJM 2014; Furman et al, NEJM 2014). The mechanisms of resistance to second generation BTK inhibitors are currently unknown. We aimed to assess the spectrum of acquired BTK mutations in patients with CLL progression on zanubrutinib (ZANU), a second-generation, irreversible inhibitor of BTK. We identified 38 CLL patients, treated with ZANU on clinical trials (NCT02343120, NCT02569476, NCT03336333, NCT02795182) at three centres, for whom serial samples were available. Four of 38 patients (10.5%) had CLL progression on ZANU (time to progression 5, 26, 29 and 48 months) and underwent amplicon next generation sequencing (NGS) of BTK (exon 11, 15, 16) and PLCG2 (exon 16, 19-20, 24, 27-28). Remarkably, we detected a BTK kinase domain mutation, BTK Leu528Trp (NM_000061.2:c.1583T & gt;G), in all four patients progressing on ZANU. In addition, all four patients had detectable Cys481 mutations at lower variant allele frequency (VAF) than the BTK Leu528Trp (median BTK Leu528Trp 34.9% vs BTK Cys481 9.1%). Analysis of sequence reads from amplicon NGS and RNA-sequencing data demonstrated that BTK Leu528Trp and BTK Cys481 mutations were present on different alleles. Assessment of the BTK Leu528Trp and BTK Cys481 mutations with high sensitivity droplet digital PCR (ddPCR) confirmed the absence of both mutations prior to ZANU exposure in all patients (sensitivity 0.1% VAF). Longitudinal analysis of the four patients with the BTK Leu528Trp mutation demonstrated the appearance of the Leu528Trp coincident with rising measurable disease and subsequent clinical CLL progression. We then went on to test patients on ZANU without disease progression but with persistent measurable disease (n=34) by ddPCR and detected three further patients harbouring low level BTK Leu528Trp mutations (VAF & lt;1%). These mutations were first detected after a median of 40 months on ZANU therapy. The BTK Leu528Trp mutation has been described only once previously in a patient in the context of IBR resistance (who transformed with Richter's syndrome) where it co-occurred with Cys481 mutations (Maddocks et al, JAMA Oncol 2015). As the prevalence of BTK Leu528Trp among progressive disease samples in our cohort exceeds all prior reports in IBR-treated patients, we sought to further understand the specificity of BTK Leu528Trp for ZANU progression. Targeted sequencing in a cohort of 49 patients progressing on IBR from the European Research Initiative on CLL (ERIC) did not detect the BTK Leu528Trp in any patients (sensitivity 1% VAF). We went on to perform biochemical and cellular studies on the BTK Leu528Trp mutation. Assessment of enzymatic activity of BTKLeu528Trp demonstrated a significant loss of activity compared to both BTKWT and BTKCys481Ser. This was further confirmed by assessing BTK autophosphorylation in HEK293 cells. Autophosphorylation at BTK Tyr223 was markedly reduced in HEK293 cells stably expressing BTKLeu528Trp compared to both BTKCys481Ser and BTKWT. In addition, a crystal structure of apo-BTKLeu528Trp was solved to understand effects of BTKLeu528Trp on ZANU binding to BTK. The alignment of the crystal structure of apo-BTKLeu528Trp with that of BTKWT-ZANU or the modeled structure of BTK-ATP suggested potential steric clashes between BTKLeu528Trp and ZANU (Figure 1A), as well as BTKLeu528Trp and ATP (Figure 1B). In conclusion, we have described the novel enrichment of BTK Leu528Trp mutations occurring in patients with CLL progressing on ZANU and both structural and experimental data consistent with this mutation resulting in interference with both ATP and ZANU binding to BTK. These findings emphasize the potential for agent-specific resistance mutations with second generation BTK inhibitors and the need to include these mutations in diagnostic screening for BTK resistance in the clinic. SH/CPST co-first authors, CT/PB co-senior authors Disclosures Handunnetti: Abbvie: Other: Travel Grant; Gilead: Honoraria. Zhou:Beigene: Employment. Sun:Beigene: Employment. Xing:Beigene: Employment. Zhang:Beigene: Employment. Guo:Beigene: Employment. Sutton:Abbvie: Honoraria; Gilead: Honoraria; Janssen: Honoraria. Ghia:Dynamo: Consultancy, Honoraria; ArQule: Consultancy, Honoraria; BeiGene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Sunesis: Consultancy, Honoraria, Research Funding; Acerta/AstraZeneca: Consultancy, Honoraria; Pharmacyclics LLC, an AbbVie Company: Consultancy; Novartis: Research Funding; Juno/Celgene: Consultancy, Honoraria. Scarfo:AstraZeneca: Honoraria; Janssen: Honoraria; AbbVie: Honoraria. Seymour:Takeda: Consultancy; Acerta: Consultancy; Celgene: Consultancy, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Research Funding; Roche: Consultancy, Research Funding, Speakers Bureau. Anderson:Walter and Eliza Hall Institute: Employment, Patents & Royalties: Institute receives royalties for venetoclax, and I receive a fraction of these.. Roberts:AbbVie: Other: Unremunerated speaker for AbbVie, Research Funding; Australasian Leukaemia and Lymphoma Group: Membership on an entity's Board of Directors or advisory committees; Walter and Eliza Hall Institute: Patents & Royalties: Institute receives royalties for venetoclax, and I receive a fraction of these.; Janssen: Research Funding; BeiGene: Research Funding. Huang:Genentech: Patents & Royalties: DCSH is an employee of the Walter and Eliza Hall Institute which receives milestone and royalty payments related to venetoclax. Liu:Beigene: Employment. Cheah:Roche, Janssen, MSD, Gilead, Loxo Oncology, Acerta, BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene, Roche, Abbvie: Research Funding; Roche: Other: Travel expenses. Tam:Janssen: Honoraria, Research Funding; BeiGene: Honoraria; Pharmacyclics LLC, an AbbVie company: Honoraria; Roche: Honoraria; Novartis: Honoraria; AbbVie: Honoraria, Research Funding. Blombery:Janssen: Honoraria; Invivoscribe: Honoraria; Novartis: Consultancy.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2019
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  • 8
    In: Blood, American Society of Hematology, Vol. 136, No. Supplement 1 ( 2020-11-5), p. 30-31
    Abstract: INTRODUCTION. Kinase inhibitors and glycoengineered monoclonal antibody, such as obinutuzumab (G), have significantly changed the treatment landscape of chronic lymphocytic leukemia (CLL). Both like the BTK inhibitor ibrutinib (IB) and obinutuzumab plus chlorambucil (G-CHL) are approved as first line therapy in CLL patients unfit for a fludarabine-base treatment. While IB has proved to be superior to bendamustine-rituximab in a phase 3 trial and an ongoing retrospective ERIC study, no head-to-head comparison has been done for IB vs G-CHL in a real-world evidence study. The aim of this study was to compared the clinical efficacy of the fixed duration G-CHL treatment vs continuous treatment with IB. METHODS. The inclusion criteria for this observational study were patients with a diagnosis of CLL, requiring treatment according to the iwCLL guideline (Hallek M, Blood 2018) and considered unfit for fludarabine-base therapy by the treating physician belonging to the Italian CLL campus. Patients received ibrutinib 420mg daily until progression or unacceptable toxicity, while G was administrated at 100mg on day 1, 900mg on day 2 and 1000mg on days 8 and 15 of the 1st cycle, then at 1000mg from cycles 2-6. Chlorambucil was administrated according to the local policy. An IGHV gene sequence homology ³98% was considered as unmutated (U-IGHV), as opposed to mutated (M-IGHV). TP53 disruptions (TP53dis) included deletions and mutations. Progression-free survival (PFS), time-to-next treatment (TTNT) and overall survival (OS) were calculated according to the iwCLL 2018 guideline. Minimal residual disease (MRD), assessed by flow cytometry, was considered undetectable when & lt;10-4 (uMRD4). Survival curves were compared with the log-rank test and p & lt;0.05 was considered as significant. The study was approved by the ethic committee of Padua university hospital. RESULTS. We recruited 284 CLL patients from 16 hematologic centers, 104 were treated with G-CHL and 180 with IB as first-line treatment. Once TP53dis cases were excluded, 102 patients treated with G-CHL and 80 treated with IB were included for further analysis. Among patients managed with G-CHL the median age was 75 years and 20% were older than 80 years, 47% had a CIRS≥6 (range 2-18), 68% had a clearance creatinine & lt;70ml/min, 60% showed a Rai stage III-IV, 32% were U-IGHV and 11% harbored 11q deletion by FISH. Patients treated with IB displayed a better renal function (p=0.0011) and were enriched in U-IGHV cases (p=0.0001). After a median follow-up of 21 months, 23 patients relapsed (20 G-CHL, 3 IB), 16 required a subsequent treatment (14 G-CHL, 2 IB) and 17 died (10 G-CHL and 7 IB). Two patients in the IB arm developed Richter syndrome. After 8 months from the start of treatment, the overall response rates in the G-CHL and IB arms were 86% vs 77% (p=0.1480), including 25% vs 6% complete remissions (CR, p=0.0013) and 61% vs 71% partial responses (PR, p=0.6320). Remarkably, an uMRD4 by flow-cytometry was documented in 42% and 9% of G-CHL patients in the peripheral blood and bone marrow, respectively. The median PFS was 33 months for G-CHL arm, but not reached for IB patients. The 24months PFS, TTNT and OS was 67% vs 91% (p=0.0012), 83% vs 97% (p=0.0128) and 89% vs 95% (p=0.5314) for the G-CHL and IB arms, respectively. Interestingly, the depth of response influenced PFS only in the G-CHL arm both in terms of clinical response (the median PFS was 8, 29 and 38 months for no responding, PR and CR patients) and MRD status (the 24 months PFS was 82% vs 50% and 100% vs 58% for uMRD4 vs MRD+ evaluated on peripheral blood and bone marrow). While the PFS was significantly better with IB than with G-CHL in U-IGHV (p=0.007), it was superimposable for M-IGHV patients (p=0.1946). Dose reductions or discontinuations were recorded in 39% and 44% of patients in the G-CHL and IB arms. Atrial fibrillation and infections occurred in 2% and 6% (p=0.0442), and in 25% and 17% (p=0.1455) of patients in the G-CHL and IB arms, respectively. CONCLUSIONS. The Italian experience with G-CHL confirms the marked efficacy and safety of this combination, in particular for patients who reach a CR and/or an uMRD4. The continuous treatment with ibrutinib provides a better disease management in CLL patients unfit for fludarabine-base therapy, but some on them - particularly those with a M-IGHV status - can achieve a long-term disease control with a fixed duration obinutuzumab-based chemoimmunotherapy. Disclosures Visentin: Janssen: Honoraria; Gilead: Honoraria; Abbvie: Honoraria. Mauro:Takeda: Membership on an entity's Board of Directors or advisory committees; Octopharma: Consultancy; Astrazeneca: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jannsen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Vitale:Janssen: Honoraria. Ciolli:Janssen: Honoraria; Abbvie: Research Funding. Sportoletti:Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Rigolin:Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Murru:Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Gozzetti:Janssen: Honoraria, Research Funding; Takeda: Honoraria; Amgen: Honoraria. Molica:Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees. Marchetti:Pfizer: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees. Scarfo:Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria. Reda:Gilead: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Coscia:Karyopharm Therapeutics: Research Funding; Shire: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Laurenti:Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees. Pizzolo:Abbvie: Speakers Bureau; janssen: Speakers Bureau. Semenzato:Takeda: Honoraria; Roche: Honoraria; Abbvie: Honoraria. Foà:Novartis: Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees. Cuneo:Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Trentin:Shire: Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Octapharma: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2020
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  • 9
    In: Blood, American Society of Hematology, Vol. 122, No. 21 ( 2013-11-15), p. 4157-4157
    Abstract: Chronic lymphocytic leukemia (CLL) develops in a stepwise fashion, starting in a restricted set of normal B lymphocytes that clonally expand, presumably due to antigen stimulation, reaching levels exceeding normal homeostasis but less than required for a diagnosis of CLL. Immunologic, genetic, and epidemiologic studies suggest these clonal expansions, termed monoclonal B lymphocytosis (MBL), are requisite precursors of CLL. Although ∼5% of normal subjects over age of 60 years old exhibit MBL, only ∼1% evolve to overt CLL each year. Hence, it is likely the genetic factors leading to the development of MBL from normal B cells are not sufficient to automatically lead to CLL and additional genetic lesions are needed for the final conversion to leukemia. To understand the development of MBL and its evolution to CLL, we investigated gene expression profiles of normal blood (N) B cells, MBL cells, and CLL cells using microarray technology. Methods RNA was purified from 31 N CD19+ B cells, 21 CD19+CD5+CD20dimIgL-restricted MBL cells, and 65 CD5+CD19+ CLL cells. Microarray assays were performed using Illumina Human HT12 BeadChips. Genes differentially expressed between the 3 populations were identified (MBL vs N and MBL vs CLL) and sets of significant genes (≥1.5 fold change and P 〈 0.01) were analyzed using Ingenuity Pathway Analysis (IPA). Results Focusing on comparisons between MBL and N B cells, 1040 genes were higher and 868 lower in MBL than N B cells. Genes higher in MBL fall into different IPA categories including “PI3K/AKT Signaling” and “Inflammatory Disease”, thereby further underscoring a potential role of antigenic/inflammatory stimuli at the origin of MBL. In the “Inflammatory Disease” category, genes belonging to IFNα pathway were over-expressed in MBL. Eighteen of these IFN-associated genes overlapped with 74 genes in a type I IFN signature characteristic of systemic lupus erythematosus (SLE). Interestingly, 4 genes belonging to the “Post-Translational Modification” category that were more expressed in MBL - SPOP, SPK1, SRRM1, and ADAR (all P 〈 0.0001) - have been directly linked to SLE. Finally, 21 genes in the Wnt/b-catenin pathway were also overexpressed in MBL compared with N B cells. Among these genes are WNT ligands (WNT3, 10A, and 5b), receptors (ROR1 and FZD3), effectors (TCF3, 4, and 25 and LEF1), targets (CCND1 and 3), inhibitors (GSKB, TLE4, PIN1, and AES) (all P 〈 0.0001). In contrast, the 683 genes more expressed in CLL than MBL B cells fall into the “Cell Death and Survival” and “Cancer” categories. Of note, several of the genes in the Wnt pathway over-expressed between MBL and N were lower in CLL B cells; however, since these comparisons were not paired (i.e., MBL clones that evolved to CLL were not studied), some of these differences may be spurious since we expect that not all MBL cases would evolve into CLL. Discussion Our studies implicate several pathways in the development and evolution of MBL. First, an interferon pathway, similar to that activated in SLE, may be operational in MBL, hinting such signaling is involved in the amplification of MBL clones and associating CLL precursors with autoimmunity, a well documented fact for overt CLL cells. Second, over-representation of genes involved in RNA processing suggests this function is also important in MBL. This again associates MBL with CLL and autoimmunity as splicing factor mutations have been identified in CLL and the small nuclear ribonucleoproteins involved in splicing are often autoantibody targets in SLE. Of note, mutations that affect SF3B1 and its splicing function have been recently described in a subset of CLL patients and implicated in its pathogenesis. Finally, our data strongly incriminate the Wnt/b-catenin pathway in MBL. Since both Wnt ligand and receptor genes are upregulated, autocrine as well as paracrine loops may be operative. It is interesting that the WNT effector, LEF1, which has been reported as upregulated in MBL previously, is an interferon-responsive gene, possibly linking those two pathways. Finally, if not an artifact of sample availability, it is curious that most of the Wnt pathway genes diminish in expression at the level of manifest CLL. Additional studies are needed to determine the functional relevance of our observations to MBL and CLL B-cell biology. Disclosures: No relevant conflicts of interest to declare.
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    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2013
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  • 10
    In: Blood, American Society of Hematology, Vol. 127, No. 16 ( 2016-04-21), p. 1987-1997
    Abstract: HIF-1α critically regulates the interaction of neoplastic CLL cells with the leukemic microenvironment. HIF-1α is regulated at the transcriptional level in CLL patients and correlates with CXCR4 expression.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2016
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