Chromatin Accessibility Profiling Reveals Cis-Regulatory Heterogeneity and Novel Transcription Factor Dependencies in Multiple Myeloma

Abstract Multiple myeloma (MM) is a plasma cell malignancy characterized by clinical and genomic heterogeneity. Recurrent IgH translocations, copy number abnormalities and somatic mutations have been reported to participate in myelomagenesis; however no universal driver of the disease has been identified. Here, we hypothesize that transcriptional deregulation is critical for MM pathogenesis and the maintenance of the MM cell state. In order to capture signatures of transcription factor engagement with the myeloma epigenome, we performed the assay for transposase-accessible chromatin sequencing (ATAC sequencing), deep RNA sequencing in 23 primary myeloma samples and 5 normal plasma cell samples (NPC) from healthy donors along with whole genome sequencing and H3K27ac ChIP-seq in a cohort of these primary MM samples. We identified 22,603 variable accessible loci between MM and NPC and correlated impact of these on expression of associated genes using RNA-seq data. Together with robust differential analysis of open chromatin regions and nuclease-accessibility footprints to identify discrete transcription factor binding events, we have discerned the myeloma-specific open chromatin landscape, identified transcription factor dependencies and potential new myeloma drivers. In our dataset we observe a vast number of loci with heterogeneous chromatin states across the sample cohort, and the majority of the open chromatin sites identified are unique to a single sample. However, distinct variable chromatin accessibility signatures indicative of the MM chromatin state when compared to normal plasma cells were observed. Remarkably, we observed more frequent recurrent loss of variable accessible loci compared to gains. In addition, specific open chromatin profiles evident in hyperdiploid and non-hyperdiploid MM were also identified. Accessibility footprinting revealed MM-specific enrichment for transcription factors known to be essential for MM cell survival including Interferon Regulatory Factors (IRFs), Nuclear Factor Kappa B (NFkB), Ikaros, and Sp1. Interestingly, we also identify the myocyte enhancer factor 2 (MEF2) family of transcription factors as being specifically enriched in open chromatin regions in MM cells. Using a CRISPR-Cas9 knockout system, we identify the MEF2 family member MEF2C as essential for MM cell proliferation and survival. MEF2C is significantly overexpressed at the RNA level in our study as well as in several independent cohorts and is a central enhancer-localized transcription factor in MM core regulatory circuitry as determined by H3K27ac ChIP-sequencing profiles of primary MM samples. In order to evaluate MEF2C as a therapeutic target, we used small molecule inhibitors targeting MEF2C activity via inhibition of MEF2C phosphorylation using inhibitors of salt-induced kinases (SIK) and microtubule-associated protein/microtubule affinity regulating kinases (MARK). SIK/MARK have been described to specifically activate MEF2C. SIK and MARK inhibition resulted in both dose- and time-dependent inhibition of MM cell growth and survival in a panel of 12 MM cell lines with various genotypic and phenotypic characteristics, revealing a potential approach to targeting the dysregulated gene regulatory state of myeloma. To conclude, here we identify here an altered chromatin accessibility landscape in multiple myeloma that likely contributes to oncogenic transcription states through the activity of transcription factors such as MEF2C, representing a new MM dependency and potential therapeutic target. Disclosures Anderson: Millennium Takeda: Consultancy; C4 Therapeutics: Equity Ownership, Other: Scientific founder; Bristol Myers Squibb: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; OncoPep: Equity Ownership, Other: Scientific founder. Young:Camp4 Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Syros Pharmaceuticals: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Omega Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Munshi:OncoPep: Other: Board of director.

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Targeting Distinct Promoter- and Enhancer-Driven Dependencies in Multiple Myeloma

Blood ◽

10.1182/blood-2018-99-112583 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 3156-3156

Author(s):

Chandraditya Chakraborty ◽

Mehmet Kemal Samur ◽

Richard A. Young ◽

Kenneth Anderson ◽

Charles Y Lin ◽

...

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Multiple Myeloma ◽

Transcription Factor ◽

Board Of Directors ◽

Associated Factors ◽

Low Doses ◽

Advisory Committees ◽

Genetic Changes ◽

Equity Ownership

Abstract Uncontrolled proliferation is a hallmark of tumorigenesis and is associated with perturbed transcriptional profiles. The proliferative program in Multiple myeloma (MM), a complex disease with heterogeneous genetic changes, is controlled by transcription factors (TFs) and chromatin-associated factors. The dependency on these transcriptional regulators, leading to the dysregulated proliferation, is not predicted by genetic changes, making the tumor cells more sensitive to inhibition of these regulators than normal cells.The relationship between promoter proximal transcription factor-associated gene expression and super-enhancer-driven transcriptional programs is not well-defined. However, their distinct genomic occupancy suggests a mechanism for specific and separable gene control. Our genome-wide epigenomic profile in myeloma has identified the existence of two non-overlapping regulatory axes controlled by promoter and enhancer-driven processes, governing distinct biological functions. We have utilized E2F1 as promoter proximal transcription factor, and evaluated its transcriptional and functional interrelationship with enhancer-associated factors, such as BET bromodomain transcriptional co-activators. We identified that the transcription factor E2F1 and its heterodimerization partner DP1 represent a dependency in MM cells. Global chromatin analysis revealed two distinct regulatory axes, with E2F and MYC predominantly localized to active gene promoters of growth/proliferation genes and CDK9 and BETs disproportionately at enhancer-regulated tissue-specific genes. This divergent BRD4 enhancer and E2F promoter axes is also observed in diffuse large B-cell lymphoma, suggesting a more broader transcriptome control process. Dual inhibition of E2F and BETs displays a superior activity against MM cell growth and viability, both in vitro and in vivo, compared to single perturbation alone providing an important molecular mechanism for combination therapy. Moreover, at low doses of BRD4 inhibitor JQ1, the addition of E2F1 depletion down-regulates the promoter controlled proliferation gene expression axis. As for many TFs, direct pharmacologic inhibition of E2F remains a difficult challenge in drug discovery. However, E2F is not entirely "undruggable" as inhibitors of upstream regulators of the pRB-E2F axis are available. For example, a number of Cyclin dependent kinases (CDK) 4/6 inhibitors, including Palbociclib are now being investigated in clinical trials in in fact approved by the FDA in select malignancies. CDKs are serine threonine kinases that modulate cell cycle progression. CDK4 and CDK6 together with D-type cyclins and cyclin E/CDK2 complexes control the commitment to cell cycle entry from quiescence and the G1 phase. These kinase complexes can phosphorylate RB, releasing E2F to modulate the expression of E2F target genes that are required for S phase entry. We investigated combination of low doses of JQ1 and Palbociclib and observed a profound effect on E2F promoter driven transcriptional activity, and was highly synergistic with JQ1 in a large panel of MM cell lines and primary MM cells from newly diagnosed and relapsed patients. Cell cycle analysis revealed complete G1 arrest after treatment. Importantly, the combination regimen was not effective in healthy donor PBMCs activated with PHA, suggesting a favorable therapeutic index. Transcriptomic changes to assess the impact on promoter and SE-driven processes are ongoing and will be presented. In conclusion, these data implicates the existence of a sequestered cellular functional control that may be perturbed in cancer to maintain the tumor cell state. Simultaneous targeting of non-overlapping promoter and enhancer vulnerabilities impairs the myeloma proliferative program, with potential for development of a promising therapeutic strategy in MM and other malignancies. Disclosures Young: Omega Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Syros Pharmaceuticals: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Camp4 Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Anderson:Bristol Myers Squibb: Consultancy; C4 Therapeutics: Equity Ownership, Other: Scientific founder; Celgene: Consultancy; Millennium Takeda: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; OncoPep: Equity Ownership, Other: Scientific founder. Munshi:OncoPep: Other: Board of director.

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Transcriptional Signaling Centers Govern Human Erythropoiesis and Harbor Genetic Variations of Red Blood Cell Traits

Blood ◽

10.1182/blood-2018-99-118637 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1277-1277

Author(s):

Avik Choudhuri ◽

Eirini Trompouki ◽

Brian J. Abraham ◽

Leandro Colli ◽

William Mallard ◽

...

Keyword(s):

Gene Expression ◽

Transcription Factor ◽

Transcription Factors ◽

Blood Cell ◽

Board Of Directors ◽

Red Blood Cell ◽

Erythroid Differentiation ◽

Regulatory Elements ◽

Advisory Committees ◽

Equity Ownership

Abstract Single Nucleotide Polymorphisms (SNPs) identified through genome-wide association studies (GWAS) provide insight into the mechanism of human genetic diseases, and majority of functional GWAS mutations target genomic regulatory elements. During erythroid differentiation of human CD34+ cells, we mapped regulatory DNA elements (enhancers and open chromatin regions) by H3K27Ac ChIP-seq and ATAC-seq, and studied the SNPs that reside within these DNA regulatory elements. We followed genomic binding of lineage restricted GATA transcription factors and also chose to examine the binding of the BMP signal responsive transcription factor SMAD1 in CD34+ cells during erythropoiesis. By overlapping their genomic occupancy with stage-matched RNA-seq, we found that SMAD1, in association with GATA-factors, serves as marker of genes responsible for differentiation at every step of erythropoiesis. ChIP-seq for other crucial signaling transcription factors, such as WNT-responsive and TGFb-responsive factors (TCF7L2 and SMAD2, respectively) demonstrated a remarkable co-existence of such factors at GATA+SMAD1 co-bound regions nearby stage-specific genes. We defined such regions as "Transcriptional Signaling Centers (TSC)" where multiple signaling transcription factors converge with master transcription factors to determine optimum stage-specific gene expression in response to growth factors. Our bioinformatics-algorithms demonstrated that PU1 and FLI1 binding sites were present in progenitor-specific TSCs whereas KLF1 and NFE2 sites were enriched in TSCs of red blood cells. We performed CRISPR-CAS9 mediated perturbations of each of the PU1, GATA and SMAD1 motifs separately in a representative progenitor TSC in K562 and HUDEP2 cells. Similar to loss of PU1 and GATA motifs, loss of SMAD1 motif selectively inhibited expression of the associated gene and showed defects in erythroid differentiation, demonstrating that TSCs are important to provide optimum gene expression and proper erythroid differentiation. To determine if such TSCs are targeted by GWAS mutations, we have studied 1270 lead and additional 27,799 SNPs in linkage disequilibrium with lead SNPs that are associated with six critical red blood cell traits - hemoglobin concentration (Hb), hematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and red blood cell count (RBC). Surprisingly, we observed that, out of the 3831 "functional" SNPs that fall within non-exonic H3K27Ac enhancers, while only 5% (188) of RBC-SNPs target only blood-master-transcription-factor motifs, at least 48% (1821) of them reside on various signaling pathway associated transcription factor motifs including SMADs (BMP/TGFb signaling), RXR/ROR (nuclear receptor signaling), FOXO/FOXA (FOX signaling), CREBs (cAMP signaling) and TCF7L2 (WNT signaling). Additionally, these RBC-trait-SNPs are specifically enriched in GATA+SMAD1 co-bound TSCs and fall within signaling factor binding sites. We validated such SNPs that target SMAD-motifs. The SNP rs9467664 is associated with the MCV-trait near HIST1H4A, a gene that increases in expression during differentiation. Using gel-shift assay, we found that SMAD1 binding is compromised when the major allele T changes to minor allele A under MCV-trait. Remarkably, eQTL analysis using microarray gene expression profiles of peripheral blood obtained from the Framingham Heart Studies revealed that expression of HIST1H4A is significantly more in a population with T-allele than that with A-allele. This demonstrates that inhibition of SMAD1 binding by the SNP causes a loss of allele-specific HIST1H4A expression. Another MCV-associated SNP rs737092 targets a SMAD motif within an erythroid-specific TSC near RBM38 gene. T-allele, in comparison with C-allele, that retains SMAD1 binding showed more expression in luciferase-based reporter assays specifically under BMP stimulation suggesting that rs737092 compromise BMP-responsiveness. Taken together, our study provides the first evidence that naturally occurring GWAS variations directly impact gene expression from signaling centers by modulating binding of signaling transcription factors under stimulation. Such aberrant signaling events over time could lead to "signalopathies", ultimately resulting in phenotypic variations of RBC traits. Disclosures Abraham: Syros Pharmaceuticals: Equity Ownership. Young:Omega Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Syros Pharmaceuticals: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Camp4 Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

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Mapping of the Multiple Myeloma Transcriptional Core Regulatory Circuitry Reveals TCF3 As a Novel Dependency and an Oncogenic Collaborator of MYC

Blood ◽

10.1182/blood.v130.suppl_1.64.64 ◽

2017 ◽

Vol 130 (Suppl_1) ◽

pp. 64-64

Author(s):

Charles Y Lin ◽

Mariateresa Fulciniti ◽

Michael A Lopez ◽

Mehmet Kemal Samur ◽

Raphael Szalat ◽

...

Keyword(s):

Multiple Myeloma ◽

Transcription Factor ◽

Transcription Factors ◽

Board Of Directors ◽

Cell Lines ◽

Plasma Cells ◽

Myeloma Cell ◽

Advisory Committees ◽

Myeloma Cells ◽

Over Time

Abstract Multiple Myeloma (MM) is a complex plasma cell malignancy driven by numerous genetic and epigenetic alterations that are acquired over time. The events controlling and modifying transcriptomic changes that drive MM cell growth and progression remains undefined. To reveal the epigenetic circuitry governing myeloma cells, we performed a comprehensive analysis integrating data obtained from Multiplexed Indexed T7 Chromatin IP (Mint-ChIP), Assay for Transposase-Accessible Chromatin with high-throughput sequencing (ATAC-Seq), and RNA-seq in 10 primary MM cells as well as 3 MM cell lines to identify genome-wide the master transcription factors (TFs), the enhancer elements they occupy, and the genes they regulate. Using these data, we have identified myeloma-specific core regulatory circuitry which includes several well-established regulators of MM such as IKZF, E2F, MYC and IRF family of genes. For example, our data show elevated MYC at numerous tissue specific enhancers in myeloma cells, including those that regulate lineage specifying transcription factors such as IRF4 and TCF3 (aka E2A). When translocated to the immunoglobulin enhancer, MYC in turn is regulated by these lineage transcription factors thus integrating MYC into the interconnected transcriptional core regulatory circuitry of MM (Figure 1a,b). We propose that this oncogenic "re-wiring" accounts for the observed addiction of MM cells to lineage factors such as IRF4 and in this work, we implicate the B-cell factor TCF3 as a novel multiple myeloma dependency. Using myeloma cell lines and primary samples, we observed elevated enhancer activity at TCF3 in primary CD138+ cells from myeloma patients compared to normal plasma cells (NPCs) (Figure 1c). As a result, TCF3 expression is significantly upregulated in our large cohort of MM patients (n=370) compared to normal bone marrow plasma cells (n=18). As MYC proteins can only bind pre-established and acetylated regions of active chromatin, we hypothesize that enhancer specifying lineage transcription factors such as TCF3 may cooperate with MYC to alter tissue specific gene expression programs. We show that TCF3 is regulated by a large proximal enhancer that is bound by MYC, and is highly sensitive to chemical perturbation of enhancer co-activators such as BRD4. As a helix-loop-helix transcription factor that similar to MYC binds short (CANNTG) E-box sequences, we computationally predict co-occupancy of MYC and TCF3 at ~80% of all enhancers that form the multiple myeloma transcriptional core regulatory circuitry. To evaluate the functional role of TCF3 in myeloma cells, we established TCF3 knock down myeloma cell lines and followed the cell growth over time. Stable knockdown of TCF3 preferentially blocks proliferation of IgH MYC translocated cell lines (such as MM1.S cells) versus non-translocated lines (such as U266 cells). Finally, high expression of TCF3 correlates with poor clinical outcome in myeloma patients. Together these data suggest TCF3 acts as an oncogenic collaborator with deregulated MYC and implicates transcriptional control of lineage as a dependency in multiple myeloma. Figure 1: Transcriptional core regulatory circuitry of multiple myeloma: A) ChIP-Seq tracks of IRF4, MYC, BRD4, and H3K27ac occupancy at the IRF4, IgH enhancer, and TCF3 loci respectively. B) Schematic of transcription factor to enhancer connectivity of the partial multiple myeloma transcriptional core regulatory circuitry highlighting interactions between IRF4, MYC, and TCF3 (computationally predicted based on TCF3 motif data). C) ChIP-Seq tracks of H3K27ac occupancy at the TCF3 locus in patient multiple myeloma (top, n=3) or normal plasma cells (bottom, n=2). Figure 1 Figure 1. Disclosures Bradner: Acetylon: Other: Scientific Founder; Novartis: Employment. Anderson: Oncopep: Other: scientific founder; Millenium Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; C4 Therapeutics: Other: scientific founder; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Membership on an entity's Board of Directors or advisory committees; MedImmune: Membership on an entity's Board of Directors or advisory committees.

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Primary Plasma Cell Leukemia Outcomes Remain Dismal Despite Novel Agents and Hematopoietic Cell Transplantation

Blood ◽

10.1182/blood-2019-127049 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 266-266

Author(s):

Sagar Patel ◽

Saulius K. Girnius ◽

Binod Dhakal ◽

Lohith Gowda ◽

Raphael Fraser ◽

...

Keyword(s):

High Risk ◽

Board Of Directors ◽

Plasma Cell ◽

Research Funding ◽

Hematopoietic Cell Transplantation ◽

Disease Status ◽

Cell Leukemia ◽

Advisory Committees ◽

Primary Plasma Cell Leukemia ◽

Equity Ownership

Background Primary plasma cell leukemia (pPCL) is a rare plasma cell neoplasm with a high mortality rate. There have been improvements in multiple myeloma (MM) outcomes with novel induction agents and use of hematopoietic cell transplantation (HCT) with maintenance, but similar progress has not been reported for pPCL. We examined the outcomes of pPCL patients receiving novel agents with autologous (autoHCT) or allogeneic (alloHCT) approaches as reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) in the modern era. Methods From 2008 to 2015, 348 pPCL pts underwent HCT (N = 277 - autoHCT and 71 - alloHCT) with 45% and 48% having research level data available, respectively. Cumulative incidences of non-relapse mortality (NRM) and relapse/progression (REL), and probability of progression-free survival (PFS) and overall survival (OS) were calculated. Cox multivariate regression was used to model survival after autoHCT only. Median follow-up in autoHCT and alloHCT was 48 and 60 months, respectively. Results AutoHCT Cohort Median age was 60 years and 93% received HCT within 12 months of diagnosis with 76% after a single line of induction (Table 1). 35% had high risk cytogenetics. 23% received bortezomib, doxorubicin, cisplatin, cyclophosphamide, and etoposide (VDPACE). Moreover, 40% received bortezomib (BTZ) and immunomodulatory drug (IMIID)-based triplets. Disease status at HCT was VGPR or better in 47%. 27% received maintenance therapy. At 4 years post-HCT, NRM was 7% (4-11%), REL 76% (69-82%), PFS 17% (13-23%), and OS 28% (22-35%) (Figures 1A, 2A, 2B). Disease status ≥VGPR at HCT and Karnofsky Performance Score >90 significantly predicted superior OS in multivariate analysis. AlloHCT Cohort Median age was 53 years and 89% received HCT within 12 months of diagnosis (Table 1). 61% received a single alloHCT, while 39% used auto-alloHCT tandem approach. 42% had high-risk cytogenetics. 61% received total body irradiation with 44% receiving myeloablative conditioning. Use of VDPACE was higher at 41% in this cohort. VGPR status at HCT was similar (48%), while maintenance was used less often (12%). Grade II-IV acute GVHD occurred in 30% and chronic GVHD in 45%. At four years post-HCT, NRM was 12% (5-21%), REL 69% (56-81%), PFS 19% (10-31%), and OS 31% (19-44%) (Figures 1A, 1B, 2A, 2B). There were no differences in outcomes based on type of HCT. A comparison of post-HCT outcomes of CIBMTR pPCL patients from 1995 to 2006 showed that PFS and OS outcomes are inferior despite lower NRM in this modern cohort (Mahindra et al. Leukemia. 2012). In addition, analysis of SEER (1995-2009) and CIBMTR databases showed that use of HCT increased from 12% (7-21%) in 1995 to 46% (34-64%) in 2009. Conclusion More newly diagnosed pPCL patients are receiving modern induction regimens translating into a higher proportion receiving HCT, but without significant further benefit post-HCT. Post-HCT relapse remains the biggest challenge and further survival in pPCL will likely need a combination of targeted and cell therapy approaches. This study provides a benchmark for future HCT studies for pPCL. Disclosures Girnius: Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Dhakal:Takeda: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria. Shah:University of California, San Francisco: Employment; Indapta Therapeutics: Equity Ownership; Genentech, Seattle Genetics, Oncopeptides, Karoypharm, Surface Oncology, Precision biosciences GSK, Nektar, Amgen, Indapta Therapeutics, Sanofi: Membership on an entity's Board of Directors or advisory committees; Celgene, Janssen, Bluebird Bio, Sutro Biopharma: Research Funding; Poseida: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Nkarta: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kite: Consultancy, Membership on an entity's Board of Directors or advisory committees; Teneobio: Consultancy, Membership on an entity's Board of Directors or advisory committees. Qazilbash:Amgen: Consultancy, Other: Advisory Board; Bioclinical: Consultancy; Autolus: Consultancy; Genzyme: Other: Speaker. Kumar:Celgene: Consultancy, Research Funding; Takeda: Research Funding; Janssen: Consultancy, Research Funding. D'Souza:EDO-Mundapharma, Merck, Prothena, Sanofi, TeneoBio: Research Funding; Prothena: Consultancy; Pfizer, Imbrium, Akcea: Membership on an entity's Board of Directors or advisory committees. Hari:BMS: Consultancy, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Kite: Consultancy, Honoraria; Amgen: Research Funding; Spectrum: Consultancy, Research Funding; Sanofi: Honoraria, Research Funding; Cell Vault: Equity Ownership; AbbVie: Consultancy, Honoraria.

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Results of a Phase I Study of Pnk-007, Allogeneic, Off the Shelf NK Cell, Post Autologous Transplant in Multiple Myeloma (NCT02955550)

Blood ◽

10.1182/blood-2019-128467 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 4451-4451

Author(s):

Sarah A. Holstein ◽

Sarah Cooley ◽

Parameswaran Hari ◽

Sundar Jagannath ◽

Catherine R Balint ◽

...

Keyword(s):

Multiple Myeloma ◽

Maintenance Therapy ◽

Board Of Directors ◽

Research Funding ◽

Phase I Study ◽

Nk Cell ◽

Single Infusion ◽

Advisory Committees ◽

Cd34 Cells ◽

Equity Ownership

Background: PNK-007 is an allogeneic, off the shelf cell therapy product enriched for CD56+/CD3- NK cells expanded from placental CD34+ cells. PNK-007 cells exhibit cytotoxicity against various cancer cell types, including multiple myeloma (MM), and secrete cytokines during co-culture with cancer cells. This is a Phase I study of single infusion PNK-007 after autologous stem cell transplant (ASCT) in MM. Methods: Placental CD34+ cells were cultivated in the presence of cytokines for 35 days to generate PNK-007 under cGMP standards followed by release testing. HLA matching and KIR mismatching were not used. Four treatment arms were evaluated on patients (pts) following ASCT: 10 million (M) cells/kg Day (D) 14 with or without recombinant human IL-2 (rhIL-2), 30M cells/kg D14 with rhIL-2, or 30M cells/kg D7 with rhIL-2. rhIL-2 was administered subcutaneously at 6M units every other day for up to 6 doses to facilitate PNK-007 expansion. Pts received variable pre-ASCT induction therapy. Maintenance therapy was permitted after the Day 90-100 visit (D90). Subjects were followed for up to 1-year. Results: 15 pts who received PNK-007 (12 of whom received rhIL-2) were followed on this study. Pts aged 44-69 yrs included 12 newly diagnosed (ND)MM and 3 relapsed/refractory (RR)MM. The 3 RRMM pts had received 1, 2 or 5 prior lines of therapy, with 2 pts having previous ASCT. All pts had been exposed to immunomodulatory drug (IMiDs) and proteasome inhibitors (PIs). No serious adverse events (AEs) were attributable to PNK-007 and no dose-limiting toxicity, GvHD, graft failure or graft rejection were observed. 12/15 pts started maintenance therapy following the transplant while participating in this study, at the physician's discretion. Based on physician assessed responses by International Myeloma Working Group pre-ASCT, of the NDMM pts 10/12 achieved VGPR or better (1 CR and 9 VGPR), 1/12 achieved PR and 1/12 was not assessed during pre-ASCT induction. By D90 10/12 pts achieved VGPR or better (5 CR or sCR and 5 VGPR), 1/12 maintained PR and 1/12 stable disease. At 1-year 9/11 achieved VGPR or better (4 CR or sCR and 5 VGPR), 2/11 were not assessed and 1 was removed from the study prior to 1 year due to failure to respond to ASCT. Of the RRMM pts 2/3 achieved PR and 1/3 was not assessed during pre-ASCT induction, by D90 2/3 achieved VGPR and the pt that had not been assessed pre-ASCT achieved PR. At 1-year, 1 pt maintained VGPR, 1 pt was not assessed and 1 pt did not continue to the 1-year visit. Using a validated Euro-flow minimal residual disease (MRD) assay of bone marrow aspirate (BMA) samples, of the NDMM pts 4/12 were MRD negative (MRD-) pre-ASCT; by D90 9/12 were MRD-. At 1-year 6/12 were MRD-, 2/12 had insufficient BMA to perform testing, 2/12 refused BMA procedure, 1/12 did not convert to MRD-, and 1 was removed from the study prior to 1-year due to failure to respond to ASCT. Of the RRMM pts 0/3 were MRD- pre-ASCT with 1/3 having insufficient BMA to perform testing; by D90 1/3 were MRD-. At 1-year 1/3 was MRD-, 1/3 did not convert to MRD- and 1 pt did not continue to the 1-year visit. PNK-007 infusion did not interfere with immune reconstitution kinetics. Platelet, neutrophil, and absolute lymphocyte counts recovered by day 28 post-ASCT in 12/15 patients. All pts' sera tested negative for the presence of anti-HLA antibodies at all timepoints indicating the absence of humoral immunity and alloantibodies to PNK-007. Conclusion: PNK-007 is the first fully allogeneic, off the shelf CD34+ derived NK cell product in MM clinical trials. A single infusion of PNK-007 up to 30M cells/kg with and without rhIL-2 was well tolerated in the post-ASCT setting. We established the feasibility of infusing PNK-007 as early as 7 days post-ASCT without negative impact on blood count recovery or successful engraftment. BMA MRD- status was observed in 7/9 MRD evaluable pts at 1-year post ASCT. These clinical data are encouraging and warrant further evaluation. Disclosures Holstein: Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Takeda: Membership on an entity's Board of Directors or advisory committees; Sorrento: Consultancy; GSK: Consultancy; Genentech: Membership on an entity's Board of Directors or advisory committees. Cooley:Fate Therapeutics, Inc: Employment, Equity Ownership. Hari:Cell Vault: Equity Ownership; Celgene: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Research Funding; Janssen: Consultancy, Honoraria; Kite: Consultancy, Honoraria; Amgen: Research Funding; Spectrum: Consultancy, Research Funding; Sanofi: Honoraria, Research Funding; AbbVie: Consultancy, Honoraria. Jagannath:BMS: Consultancy; Merck: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Medicom: Speakers Bureau; Multiple Myeloma Research Foundation: Speakers Bureau. Balint:Celgene: Equity Ownership; Celularity, Inc: Employment. Van Der Touw:Celularity, Inc: Employment. Zhang:Celularity Inc: Employment. Hariri:Celularity Inc: Employment. Vij:Bristol-Myers Squibb: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Genentech: Honoraria; Janssen: Honoraria; Karyopharm: Honoraria; Sanofi: Honoraria; Takeda: Honoraria, Research Funding.

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Phase II Trial of the Combination of Ixazomib, Lenalidomide, and Dexamethasone in High-Risk Smoldering Multiple Myeloma

Blood ◽

10.1182/blood-2018-99-117871 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 804-804 ◽

Cited By ~ 7

Author(s):

Mark Bustoros ◽

Chia-jen Liu ◽

Kaitlen Reyes ◽

Kalvis Hornburg ◽

Kathleen Guimond ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

High Risk ◽

Disease Progression ◽

Board Of Directors ◽

Rna Sequencing ◽

Research Funding ◽

Response Rate ◽

Advisory Committees ◽

Equity Ownership

Abstract Background. This study aimed to determine the progression-free survival and response rate using early therapeutic intervention in patients with high-risk smoldering multiple myeloma (SMM) using the combination of ixazomib, lenalidomide, and dexamethasone. Methods. Patients enrolled on study met eligibility for high-risk SMM based on the newly defined criteria proposed by Rajkumar et al., Blood 2014. The treatment plan was designed to be administered on an outpatient basis where patients receive 9 cycles of induction therapy of ixazomib (4mg) at days 1, 8, and 15, in combination with lenalidomide (25mg) at days 1-21 and Dexamethasone at days 1, 8, 15, and 22. This induction phase is followed by ixazomib (4mg) and lenalidomide (15mg) maintenance for another 15 cycles. A treatment cycle is defined as 28 consecutive days, and therapy is administered for a total of 24 cycles total. Bone marrow samples from all patients were obtained before starting therapy for baseline assessment, whole exome sequencing (WES), and RNA sequencing of plasma and bone marrow microenvironment cells. Moreover, blood samples were obtained at screening and before each cycle to isolate cell-free DNA (cfDNA) and circulating tumor cells (CTCs). Stem cell collection is planned for all eligible patients. Results. In total, 26 of the planned 56 patients were enrolled in this study from February 2017 to April 2018. The median age of the patients enrolled was 63 years (range, 41 to 73) with 12 males (46.2%). Interphase fluorescence in situ hybridization (iFISH) was successful in 18 patients. High-risk cytogenetics (defined as the presence of t(4;14), 17p deletion, and 1q gain) were found in 11 patients (61.1%). The median number of cycles completed was 8 cycles (3-15). The most common toxicities were fatigue (69.6%), followed by rash (56.5%), and neutropenia (56.5%). The most common grade 3 adverse events were hypophosphatemia (13%), leukopenia (13%), and neutropenia (8.7%). One patient had grade 4 neutropenia during treatment. Additionally, grade 4 hyperglycemia occurred in another patient. As of this abstract date, the overall response rate (partial response or better) in participants who had at least 3 cycles of treatment was 89% (23/26), with 5 Complete Responses (CR, 19.2%), 9 very good partial responses (VGPR, 34.6%), 9 partial responses (34.6%), and 3 Minimal Responses (MR, 11.5%). None of the patients have shown progression to overt MM to date. Correlative studies including WES of plasma cells and single-cell RNA sequencing of the bone microenvironment cells are ongoing to identify the genomic and transcriptomic predictors for the differential response to therapy as well as for disease evolution. Furthermore, we are analyzing the cfDNA and CTCs of the patients at different time points to investigate their use in monitoring minimal residual disease and disease progression. Conclusion. The combination of ixazomib, lenalidomide, and dexamethasone is an effective and well-tolerated intervention in high-risk smoldering myeloma. The high response rate, convenient schedule with minimal toxicity observed to date are promising in this patient population at high risk of progression to symptomatic disease. Further studies and longer follow up for disease progression are warranted. Disclosures Bustoros: Dava Oncology: Honoraria. Munshi:OncoPep: Other: Board of director. Anderson:C4 Therapeutics: Equity Ownership; Celgene: Consultancy; Bristol Myers Squibb: Consultancy; Takeda Millennium: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; Oncopep: Equity Ownership. Richardson:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding. Ghobrial:Celgene: Consultancy; Takeda: Consultancy; Janssen: Consultancy; BMS: Consultancy.

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A Phase I Study of Bendamustine Combined with Lenalidomide and Dexamethasone in Patients with Refractory or Relapsed Multiple Myeloma.

Blood ◽

10.1182/blood.v114.22.1856.1856 ◽

2009 ◽

Vol 114 (22) ◽

pp. 1856-1856 ◽

Cited By ~ 1

Author(s):

Suzanne Lentzsch ◽

Amy O’Sullivan ◽

Silvana Lalo ◽

Carrie Kruppa ◽

Diane Gardner ◽

...

Keyword(s):

Multiple Myeloma ◽

Partial Response ◽

Board Of Directors ◽

Dose Level ◽

Research Funding ◽

Advisory Board ◽

Clinical Activity ◽

Advisory Committees ◽

Equity Ownership ◽

Grade 3

Abstract Abstract 1856 Poster Board I-882 Background: Lenalidomide is an analog of thalidomide that has shown significant clinical activity in patients with relapsed or refractory multiple myeloma (MM), both as a single agent and in combination with dexamethasone. Bendamustine is a bifunctional alkylating agent that is approved for the treatment of chronic lymphocytic leukemia and indolent non-Hodgkin's lymphoma that has progressed during or relapsed within 6 months following a rituximab-containing regimen. Bendamustine combined with lenalidomide may be an effective treatment option for MM patients, particularly those with preexisting or bortezomib-induced neuropathy. Our primary objective was to determine the maximum tolerated dose (MTD) and safety profile of bendamustine and lenalidomide when administered with dexamethasone for patients with relapsed or refractory MM. Methods: Patients aged ≥18 years with confirmed, measurable stage 2 or 3 MM that was refractory to or progressed after 1 or more prior therapies, including lenalidomide, received bendamustine by intravenous infusion on days 1 and 2, oral lenalidomide on days 1–21, and oral dexamethasone on days 1, 8, 15, and 22 of each 28-day cycle. Treatment was continued until a plateau of best response, as determined by the IBMTR/ABMTR, was reached. Study drug doses were escalated through 4 levels (Table), with 3–6 patients enrolled at each level depending on the rate of dose-limiting toxicity (DLT). After determining the MTD, up to an additional 12 patients will be enrolled in an MTD expansion arm to better evaluate toxicity and clinical activity. Secondary endpoints included preliminary efficacy, as evidenced by objective response, time to disease progression, and overall survival. Results: To date, 11 patients have been enrolled, with a median age of 63 years (range, 38–75 years). The MTD of bendamustine and lenalidomide has not been identified at this point; currently, patients are enrolling on dose level 3 with 100 mg/m2 bendamustine and 10 mg lenalidomide. Thus far, DLT included 1 grade 4 neutropenia at dose level 2. Nine of 11 patients are currently eligible for response assessment. A partial response was observed in 67% of patients, including 1 very good partial response and 5 partial responses (PR). Two patients experienced stable disease and 1 exhibited progressive disease. Grade 3/4 adverse events included grade 3 neutropenia, thrombocytopenia, anemia, hyperglycemia, and prolonged QTC, and 1 grade 4 neutropenia. Conclusions: Bendamustine, lenalidomide, and dexamethasone form a well-tolerated and highly active regimen even in heavily pretreated MM patients, with a PR rate of 67%. Additional updates on response and MTD will be available at the time of presentation. Disclosures: Lentzsch: Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cephalon: Consultancy, Membership on an entity's Board of Directors or advisory committees. Off Label Use: Bendamustine is not FDA approved for the treatment of multiple myeloma in the USA. Burt:Millennium: Honoraria; Celgene: Honoraria. Mapara:Resolvyx: Consultancy, Research Funding; Genzyme: Membership on an entity's Board of Directors or advisory committees; Gentium: Equity Ownership; Celgene: Spouse is consultant , has received research funding, and participates on advisory board; Cephalon: Spouse has received funding for clinical trial and participates on advisory board. Redner:Biogen: Equity Ownership; Wyeth: Equity Ownership; Glaxo-Smith-Kline: Equity Ownership; Pfizer: Equity Ownership; Genzyme: Membership on an entity's Board of Directors or advisory committees. Roodman:Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy; Acceleron: Consultancy. Zonder:Amgen: Consultancy; Pfizer: Consultancy; Cephalon: Consultancy; Millennium: Consultancy, Speaking (CME only); no promotional talks.

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A Phase I Study of Vorinostat, Lenalidomide, and Dexamethasone In Patients with Relapsed or Relapsed and Refractory Multiple Myeloma: Excellent Tolerability and Promising Activity In a Heavily Pretreated Population

Blood ◽

10.1182/blood.v116.21.1951.1951 ◽

2010 ◽

Vol 116 (21) ◽

pp. 1951-1951 ◽

Cited By ~ 4

Author(s):

Paul Richardson ◽

Donna Weber ◽

Constantine S. Mitsiades ◽

Meletios A. Dimopoulos ◽

Jean-Luc Harousseau ◽

...

Keyword(s):

Multiple Myeloma ◽

Phase I ◽

Board Of Directors ◽

Research Funding ◽

Phase I Study ◽

Response Rate ◽

Advisory Board ◽

Advisory Committees ◽

Equity Ownership ◽

Grade 3

Abstract Abstract 1951 Background: Although novel treatment combinations for multiple myeloma (MM) have improved outcomes, the disease remains incurable and new drug combinations are urgently needed. Vorinostat is an oral histone deacetylase inhibitor approved in the United States for treatment of patients (pts) with advanced cutaneous T-cell lymphoma who failed prior therapies. Vorinostat alters gene expression and protein activity, promoting MM cell death through multiple pathways, and has been shown in preclinical studies to synergistically enhance the anti-MM activity of bortezomib and immunomodulatory drugs, including lenalidomide, with or without dexamethasone. Aims: The primary objective of this Phase I study was to determine the maximum tolerated dose (MTD) of vorinostat plus lenalidomide and dexamethasone in pts with relapsed or relapsed and refractory MM. Secondary objectives included overall safety, tolerability, response rate, duration of response, and time to progression (TTP). Methods: Pts in this Phase I multicenter open-label study were sequentially enrolled into 1 of 5 escalating doses of the combination regimen using a standard 3 + 3 design for ≤8 cycles. Pts who tolerated treatment and experienced clinical benefit were eligible for enrollment in an extension phase. Toxicity was evaluated using the National Cancer Institute Common Terminology Criteria (version 3.0). Response was assessed using the modified European Group for Blood and Marrow Transplantation criteria and International Myeloma Working Group Uniform Criteria. Safety and efficacy data were analyzed using summary statistics, except for TTP, which was estimated by the Kaplan-Meier method. Results: As of July 15, 2010, 31 pts were treated and evaluable for toxicity; 4 pts remain on study. Most pts had received prior thalidomide (n=22; 71%), bortezomib (n=20; 65%), or lenalidomide (n=14; 45%), with a median of 4 prior therapies (range, 1–10). The patient population contained both high-risk and low-risk pts, based on cytogenetic and/or fluorescence in situ hybridization analyses. Most adverse events (AEs) were mild or moderate in severity. The most common grade ≥3 treatment-related AEs, experienced by 19 (61%) pts, were neutropenia (26%), thrombocytopenia (16%), diarrhea (13%), anemia (10%), and fatigue (10%); 8 pts discontinued due to toxicity. One dose-limiting toxicity (grade 3 diarrhea lasting >48 h) was observed at the maximum assessed dose (level 5), but MTD was not reached (Table) and there were no treatment-related deaths. Among 30 pts evaluable for response, the median TTP was 32 weeks (5 mo), and 4 pts remain on study as of the data cutoff date; 26 of 30 pts (87%) have achieved at least stable disease (SD). Best single responses included 2 complete responses, 3 very good partial responses (VGPR), 11 partial responses (PR), and 5 minimal responses (MR), with 5 pts achieving SD and 4 developing progressive disease, resulting in an overall response rate (ORR; PR or better) of 53%. Of 13 evaluable pts who had previously received lenalidomide, a best single response of SD or better was observed in 9 (69%; 2 VGPR, 3 PR, 1 MR, 3 SD), resulting in a 38% ORR. Notably, SD or better (2 PR, 1 MR, 3 SD) was observed in 60% of 10 evaluable pts who were relapsed, refractory, or intolerant to previous lenalidomide-containing regimens. Conclusions: Preliminary data from this Phase I study suggest that vorinostat plus lenalidomide and dexamethasone is a convenient and generally well-tolerated regimen with promising activity for relapsed or relapsed and refractory MM. The MTD for this combination was not reached. Importantly, responses were observed in pts who had received prior lenalidomide, bortezomib, and thalidomide. Further evaluation of this regimen is planned in future trials. Disclosures: Richardson: Celgene: Membership on an entity's Board of Directors or advisory committees; Millenium: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Membership on an entity's Board of Directors or advisory committees. Off Label Use: Vorinostat, Lenalidomide, and Dexamethasone for treatment in Multiple Myeloma. Weber:Novartis-unpaid consultant: Consultancy; Merck- unpaid consultant: Consultancy; Celgene- none for at least 2 years: Honoraria; Millenium-none for 2 years: Honoraria; Celgene, Millenium, Merck: Research Funding. Mitsiades:Millennium: Consultancy, Honoraria; Novartis Pharmaceuticals: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Merck & Co.: Consultancy, Honoraria; Kosan Pharmaceuticals: Consultancy, Honoraria; Pharmion: Consultancy, Honoraria; Centrocor: Consultancy, Honoraria; PharmaMar: Patents & Royalties; OSI Pharmaceuticals: Research Funding; Amgen Pharmaceuticals: Research Funding; AVEO Pharma: Research Funding; EMD Serono: Research Funding; Sunesis: Research Funding; Gloucester Pharmaceuticals: Research Funding; Genzyme: Research Funding. Dimopoulos:MSD: 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. Harousseau:Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Houp:Merck Research Laboratories: Employment. Graef:Merck Research Laboratories: Employment. Gause:Merck Research Laboratories: Employment. Byrne:Celgene Corporation: Employment, Equity Ownership. Anderson:Millennium Pharmaceuticals: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy; Merck: Consultancy; BMS: Consultancy; Acetylon: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Siegel:Celgene and Millennium: Advisory Board, Speakers Bureau; Merck: Advisory Board.

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Carfilzomib, Lenalidomide, and Dexamethasone In Newly Diagnosed Multiple Myeloma: Initial Results of Phase I/II MMRC Trial

Blood ◽

10.1182/blood.v116.21.862.862 ◽

2010 ◽

Vol 116 (21) ◽

pp. 862-862 ◽

Cited By ~ 5

Author(s):

Andrzej J Jakubowiak ◽

Dominik Dytfeld ◽

Sundar Jagannath ◽

David H. Vesole ◽

Tara B. Anderson ◽

...

Keyword(s):

Multiple Myeloma ◽

Phase I ◽

Board Of Directors ◽

Newly Diagnosed ◽

Employment Equity ◽

Advisory Committees ◽

Level 3 ◽

Equity Ownership ◽

Level 1 ◽

Level 2

Abstract Abstract 862 Background: Carfilzomib (Cfz) is a novel, irreversible proteasome inhibitor that has demonstrated promising single-agent activity and favorable toxicity profile, including very low rates of peripheral neuropathy and neutropenia in relapsed/refractory multiple myeloma (MM). Combining Cfz with Lenalidomide (Revlimid®, Len), and Dexamethasone (Dex) into CRd shows an additive anti-MM effect in preclinical studies and lack of overlapping toxicity allowing for the use of these agents at full doses and for extended duration of time in relapsed/refractory MM (Niesvizky et al, ASH, 2009). This Phase I/II study was designed to determine the maximum tolerated dose (MTD) of CRd and to assess safety and evaluate efficacy of this combination in newly diagnosed MM. Methods: In Phase I, dose escalation follows the TITE-CRM algorithm, with Cfz as the only escalating agent starting at 20 mg/m2 (level 1), maximal planned dose 27 mg/m2 (level 2), and 15 mg/m2, if needed (level -1), given IV on days 1, 2, 8, 9, 15, 16 in 28-day cycles. Len is used at 25 mg PO (days 1–21), and Dex at 40/20 mg PO weekly (cycles 1–4/5-8) for all dose levels. Based on toxicity assessment, the study was amended to add dose level 3 with Cfz at 36 mg/m2 and the number of pts in the Phase I was increased to 35. A total of 36 pts are planned to be treated at the MTD in Phase I/II. Pts who achieve ≥ PR can proceed to stem cell collection (SCC) and autologous stem cell transplant (ASCT) after ≥ 4 cycles, although per protocol design, ASCT candidates are offered to continue CRd treatment after SCC. After completion of 8 cycles, pts receive 28-day maintenance cycles with Cfz (days 1, 2 15, 16), Len days 1–21, and Dex weekly at the doses tolerated at the end of 8 cycles. Responses are assessed by IMWG criteria with the addition of nCR. Results: The study has enrolled 24 pts to date, 4 pts at level 1 (Cfz 20), 14 at level 2 (Cfz 27) and at 6 at level 3 (Cfz 36). Toxicity data are available for 21 pts, of which 19 have completed at least the first cycle required for DLT assessment; 2 pts were removed during the first cycle for events unrelated to study therapy (1 at level 1 and 1 at level 2), and 3 are currently within their first cycle of treatment. There was a single DLT event at dose level 2 (non-febrile neutropenia requiring dose reduction of Len per protocol) and the MTD has not been reached. Hematologic toxicities were reversible and included Grade (G) 3/4 neutropenia in 3 pts, G3/4 thrombocytopenia in 3, and G3 anemia in 2. There have been additional G3 non-hematologic AEs including 1 case of DVT while on ASA prophylaxis, 1 fatigue, 1 mood alteration, and 5 glucose elevations; the last 2 AEs were related to Dex. There was no emergence of peripheral neuropathy (PN), even after prolonged treatment, except in 2 pts who developed G1 sensory PN. Twenty-three pts continue on treatment, most (20 pts) without need for any dose modifications. After a median of 4 (range 1–8) months of treatment, preliminary response rates by IMWG in 19 evaluable pts who completed at least 1 cycle are: 100% ≥ PR, 63% ≥ VGPR, 37% CR/nCR, including 3 pts with sCR. Responses were rapid with 17 of 19 pts achieving PR after 1 cycle and improving responses with continuing therapy in all pts. To date, 7 pts proceeded to SCC using growth factors only, with a median 6.3 × 106 CD34+ cells/kg collected (range 4.1–8.2), after a median of 4 cycles of CRd (range 4–8); all resumed CRd treatment after SCC. After a median of 4 months of follow-up, none of evaluable pts progressed and all are alive. Conclusion: CRd is well tolerated and highly active in newly diagnosed MM with ≥ PR of 100%, including 63% ≥VGPR and 37% CR/nCR. Accrual is ongoing, with updated toxicity and efficacy data to be presented at the meeting. The results of this study represent the first report of treatment of frontline myeloma with Cfz to date, and provide additional support to recently initiated Phase 3 trial of CRd vs. Rd in relapsed MM. Disclosures: Jakubowiak: Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Exelixis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Centocor OrthoBiotech: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Off Label Use: Lenalidomide for newly diagnosed multiple myeloma. Jagannath:Millennium: Honoraria; OrthoBiotech (Canada): Honoraria; Celgene: Honoraria; Merck: Honoraria; Onyx Pharmaceuticals: Honoraria; Proteolix, Inc: Honoraria; Imedex: Speakers Bureau; Medicom World Wide: Speakers Bureau; Optum Health Education: Speakers Bureau; PER Group: Speakers Bureau. Vesole:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Anderson:Millennium: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau. Stockerl-Goldstein:Celgene: Speakers Bureau; Millennium: Speakers Bureau. Barrickman:Celgene: Employment, Equity Ownership. Kauffman:Onyx Pharmaceuticals: Employment, Equity Ownership. Vij:Proteolix: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Onyx: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

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Targeting Brouton's Tyrosine Kinase with PCI-32765 Blocks Growth and Survival of Multiple Myeloma and Waldenström Macroglobulinemia Via Potent Inhibition of Osteoclastogenesis, Cytokines/Chemokine Secretion, and Myeloma Stem-Like Cells in the Bone Marrow Microenvironment

Blood ◽

10.1182/blood.v118.21.883.883 ◽

2011 ◽

Vol 118 (21) ◽

pp. 883-883

Author(s):

Yu-Tzu Tai ◽

Betty Y Chang ◽

Sun-Young Kong ◽

Mariateresa Fulciniti ◽

Guang Yang ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Tyrosine Kinase ◽

B Cell ◽

Board Of Directors ◽

Research Funding ◽

Advisory Committees ◽

Growth And Survival ◽

Equity Ownership ◽

Trap Staining

Abstract Abstract 883 Specific expression of Bruton's tyrosine kinase (Btk) in osteoclasts (OC), but not osteoblasts (OB), suggests its role in regulating osteoclastogenesis. Although Btk is critical in B cell maturation and myeloid function, it has not been characterized in plasma cell malignancies including multiple myeloma (MM) and Waldenström Macroglobulinemia (WM). We here investigate effects of PCI-32765, an oral, potent, and selective Btk inhibitor with promising clinical activity in B-cell malignancies, on OC differentiation and function within MM bone marrow (BM) microenvironment, as well as on MM and WM cancer cells. We further define molecular targets of Btk signaling cascade in OCs and MM in the BM milieu. In CD14+ OC precursor cells, RANKL and M-CSF stimulate phosphorylation of Btk in a time-dependent fashion; conversely, PCI-32765 abrogates RANKL/M-CSF-induced activation of Btk and downstream PLCγ2. Importantly, PCI-32765 decreased number of multinucleated OC (>3 nuclei) by tartrate-resistant acid phosphatase (TRAP) staining and the secretion of TRAP5b (ED50 = 17 nM), a specific mature OC marker. It increased size of OCs and number of nuclei per OC, with significantly defective bone resorption activity as evidenced by diminished pit formation on dentine slices. Moreover, lack of effect of Dexamethasone on OC activity was overcome by combination of Dexamethasone with PCI-32765. PCI-32765 significantly reduced cytokine and chemokine secretion from OC cultures, including MIP1α, MIP1β, IL-8, TGFβ1, RANTES, APRIL, SDF-1, and activin A (ED50 = 0.1–0.48 nM). It potently decreased IL-6, SDF-1, MIP1α, MIP1β, and M-CSF in CD138-negative cell cultures from active MM patients, associated with decreased TRAP staining in a dose-dependent manner. In MM and WM cells, immunoblotting analysis confirmed a higher Btk expression in CD138+ cells from majority of MM patients (4 out of 5 samples) than MM cell lines (5 out of 9 cell lines), whereas microarray analysis demonstrated a higher expression of Btk and its downstream signaling components in WM cells than in CD19+ normal bone marrow cells. PCI-32765 significantly inhibits SDF-1-induced adhesion and migration of MM cells. It further blocked cytokine expression (MIP1a, MIP-1β) at mRNA level in MM and WM tumor cells, correlated with inhibition of Btk-mediated pPLCγ2, pERK and NF-kB activation. Importantly, PCI-32765 inhibited growth and survival triggered by IL-6 and coculture with BM stromal cells (BMSCs) or OCs in IL-6-dependent INA6 and ANBL6 MM cells. Furthermore, myeloma stem-like cells express Btk and PCI-32765 (10–100 nM) blocks their abilities to form colonies from MM patients (n=5). In contrast, PCI-32765 has no adverse effects on Btk-negative BMSCs and OBs, as well as Btk-expressing dendritic cells. Finally, oral administration of PCI-32765 (12 mg/kg) in mice significantly suppresses MM cell growth (p< 0.03) and MM cell-induced osteolysis on implanted human bone chips in a humanized myeloma (SCID-hu) model. Together, these results provide compelling evidence to target Btk in the BM microenvironment against MM and WM., strongly supporting clinical trials of PCI-32765 to improve patient outcome in MM and WM. Disclosures: Chang: Pharmacyclics Inc: Employment. Buggy:Pharmacyclics, Inc.: Employment, Equity Ownership. Elias:Pharmacyclics Inc: Consultancy. Treon:Millennium: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Genentech: Honoraria. Richardson:Millennium: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees. Munshi:Millennium: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Anderson:Millennium Pharmaceuticals, Inc.: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy; Merck: Consultancy; Bristol-Myers Squibb: Consultancy; Actelion: Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

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