scholarly journals Tecfidera Modulates Activation of Malignant B-Cells: Correlative Analysis from a Phase 1 Clinical Trial in Patients with Chronic Lymphocytic Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3143-3143
Author(s):  
Christina Wu ◽  
Emanuela M. Ghia ◽  
Fitzgerald Lao ◽  
Minya Pu ◽  
Karen Messer ◽  
...  
Keyword(s):  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Cell Activation ◽  
Phase 1 ◽  
Leukemic Cell ◽  
Lymphocytic Leukemia ◽  
Advisory Committees ◽  
Phase 1 Clinical Trial ◽  
Bcr Signaling

Abstract Tecfidera (Dimethylfumarate, DMF) is an immunomodulatory drug currently approved in the United States for the treatment of patients with multiple sclerosis (MS). DMF formulations have also been utilized for the treatment of patients with psoriasis. The ability of DMF to Inhibit autoreactive T-lymphocytes may also be applicable to malignant T- and B- lymphocytes. Indeed, preclinical studies by multiple groups have highlighted its potential efficacy as a treatment for patients with various lymphoid cancers, though inhibition of STAT, NF-KB, Wnt signaling pathways, and glycolysis. This information provided rationale to conduct a phase 1 clinical trial of DMF as a treatment for patients with relapsed chronic lymphocytic leukemia (CLL). In this study we report the correlative assessment of the initial patients who received DMF. Patients with relapsed or refractory CLL received DMF 120 mg PO BID (based on preclinical modeling with primary CLL cells in vitro and in vivo and 50% lower than the standard DMF dose for patients with MS). Treatment was planned for a short duration of 2 months to evaluate tolerability and effects on CLL cell signaling and tolerability of the drug by patients with CLL. Peripheral blood leukemic cell were isolated and analyzed by RNAseq and phosphoprotein immunoblotting at times just prior to, and 6 hours immediately following drug administration. Consistent with preclinical results (Brennan et al, PLOS one 2015; Selman et al, Science Trans Med 2018), STAT1 phosphorylation at Y701 was decreased 6 hours following the initial dose, compared to high baseline levels. Differential expression analyses for RNAseq of total RNA isolated from peripheral blood CLL cells weere performed using limma models, which compared pretreatment versus post-treatment at a specific time point. Functional annotations of these genes revealed a significant enrichment related to B-cell activation, B-cell receptor (BCR) signaling, B-cell differentiation, and immune signaling generally. Specifically, several known CLL therapy targets including SYK, LYN, and BTK were significantly downregulated. Gene-set-enrichment analysis (GSEA) revealed that the "CLL-BCR gene signature" previously described by Herishanu et al. (Blood 2011) was consistently down-regulated after DMF treatment in samples from different time points (C1D1 post, C1D8 and C2D1) compared to pretreatment samples (FDR q of 0.24, 0.01 and 0.04, respectively). In conclusion, this is the first report of the clinical use of DMF for patients with CLL in which inhibition of leukemic cell activation has been demonstrated. The inhibitory effect of DMF on leukemic cell gene expression, in particular its antagonism of BCR signaling, is valuable information for the development of novel combination strategies for CLL or other B-cell malignancies. Disclosures Kipps: F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Verastem: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Verastem: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Research Funding; Genentech Inc: Consultancy, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Choi:Gilead: Speakers Bureau; Genentech: Speakers Bureau; Rigel: Consultancy; AbbVie, Inc: Consultancy, Speakers Bureau; Pharmacyclics: Consultancy, Research Funding, Speakers Bureau.

Distinct Gene Expression Signatures in Patients with Richter's Syndrome and Chronic Lymphocytic Leukemia with Prior Exposure to Ibrutinib

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 30-31
Author(s):  
Hanyin Wang ◽  
Shulan Tian ◽  
Qing Zhao ◽  
Wendy Blumenschein ◽  
Jennifer H. Yearley ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Cell Activation ◽  
Expression Profiles ◽  
Lymphocytic Leukemia ◽  
B Cell Activation ◽  
Advisory Committees ◽  
Upregulated Genes

Introduction: Richter's syndrome (RS) represents transformation of chronic lymphocytic leukemia (CLL) into a highly aggressive lymphoma with dismal prognosis. Transcriptomic alterations have been described in CLL but most studies focused on peripheral blood samples with minimal data on RS-involved tissue. Moreover, transcriptomic features of RS have not been well defined in the era of CLL novel therapies. In this study we investigated transcriptomic profiles of CLL/RS-involved nodal tissue using samples from a clinical trial cohort of refractory CLL and RS patients treated with Pembrolizumab (NCT02332980). Methods: Nodal samples from 9 RS and 4 CLL patients in MC1485 trial cohort were reviewed and classified as previously published (Ding et al, Blood 2017). All samples were collected prior to Pembrolizumab treatment. Targeted gene expression profiling of 789 immune-related genes were performed on FFPE nodal samples using Nanostring nCounter® Analysis System (NanoString Technologies, Seattle, WA). Differential expression analysis was performed using NanoStringDiff. Genes with 2 fold-change in expression with a false-discovery rate less than 5% were considered differentially expressed. Results: The details for the therapy history of this cohort were illustrated in Figure 1a. All patients exposed to prior ibrutinib before the tissue biopsy had developed clinical progression while receiving ibrutinib. Unsupervised hierarchical clustering using the 300 most variable genes in expression revealed two clusters: C1 and C2 (Figure 1b). C1 included 4 RS and 3 CLL treated with prior chemotherapy without prior ibrutinib, and 1 RS treated with prior ibrutinib. C2 included 1 CLL and 3 RS received prior ibrutinib, and 1 RS treated with chemotherapy. The segregation of gene expression profiles in samples was largely driven by recent exposure to ibrutinib. In C1 cluster (majority had no prior ibrutinb), RS and CLL samples were clearly separated into two subgroups (Figure 1b). In C2 cluster, CLL 8 treated with ibrutinib showed more similarity in gene expression to RS, than to other CLL samples treated with chemotherapy. In comparison of C2 to C1, we identified 71 differentially expressed genes, of which 34 genes were downregulated and 37 were upregulated in C2. Among the upregulated genes in C2 (majority had prior ibrutinib) are known immune modulating genes including LILRA6, FCGR3A, IL-10, CD163, CD14, IL-2RB (figure 1c). Downregulated genes in C2 are involved in B cell activation including CD40LG, CD22, CD79A, MS4A1 (CD20), and LTB, reflecting the expected biological effect of ibrutinib in reducing B cell activation. Among the 9 RS samples, we compared gene profiles between the two groups of RS with or without prior ibrutinib therapy. 38 downregulated genes and 10 upregulated genes were found in the 4 RS treated with ibrutinib in comparison with 5 RS treated with chemotherapy. The top upregulated genes in the ibrutinib-exposed group included PTHLH, S100A8, IGSF3, TERT, and PRKCB, while the downregulated genes in these samples included MS4A1, LTB and CD38 (figure 1d). In order to delineate the differences of RS vs CLL, we compared gene expression profiles between 5 RS samples and 3 CLL samples that were treated with only chemotherapy. RS samples showed significant upregulation of 129 genes and downregulation of 7 genes. Among the most significantly upregulated genes are multiple genes involved in monocyte and myeloid lineage regulation including TNFSF13, S100A9, FCN1, LGALS2, CD14, FCGR2A, SERPINA1, and LILRB3. Conclusion: Our study indicates that ibrutinib-resistant, RS-involved tissues are characterized by downregulation of genes in B cell activation, but with PRKCB and TERT upregulation. Furthermore, RS-involved nodal tissues display the increased expression of genes involved in myeloid/monocytic regulation in comparison with CLL-involved nodal tissues. These findings implicate that differential therapies for RS and CLL patients need to be adopted based on their prior therapy and gene expression signatures. Studies using large sample size will be needed to verify this hypothesis. Figure Disclosures Zhao: Merck: Current Employment. Blumenschein:Merck: Current Employment. Yearley:Merck: Current Employment. Wang:Novartis: Research Funding; Incyte: Research Funding; Innocare: Research Funding. Parikh:Verastem Oncology: Honoraria; GlaxoSmithKline: Honoraria; Pharmacyclics: Honoraria, Research Funding; MorphoSys: Research Funding; Ascentage Pharma: Research Funding; Genentech: Honoraria; AbbVie: Honoraria, Research Funding; Merck: Research Funding; TG Therapeutics: Research Funding; AstraZeneca: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Kenderian:Sunesis: Research Funding; MorphoSys: Research Funding; Humanigen: Consultancy, Patents & Royalties, Research Funding; Gilead: Research Funding; BMS: Research Funding; Tolero: Research Funding; Lentigen: Research Funding; Juno: Research Funding; Mettaforge: Patents & Royalties; Torque: Consultancy; Kite: Research Funding; Novartis: Patents & Royalties, Research Funding. Kay:Astra Zeneca: Membership on an entity's Board of Directors or advisory committees; Acerta Pharma: Research Funding; Juno Theraputics: Membership on an entity's Board of Directors or advisory committees; Dava Oncology: Membership on an entity's Board of Directors or advisory committees; Oncotracker: Membership on an entity's Board of Directors or advisory committees; Sunesis: Research Funding; MEI Pharma: Research Funding; Agios Pharma: Membership on an entity's Board of Directors or advisory committees; Bristol Meyer Squib: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Rigel: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Cytomx: Membership on an entity's Board of Directors or advisory committees. Braggio:DASA: Consultancy; Bayer: Other: Stock Owner; Acerta Pharma: Research Funding. Ding:DTRM: Research Funding; Astra Zeneca: Research Funding; Abbvie: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Membership on an entity's Board of Directors or advisory committees; alexion: Membership on an entity's Board of Directors or advisory committees; Beigene: Membership on an entity's Board of Directors or advisory committees.

IKZF3 Overexpression Phenocopies Gain-of-Function Mutation in Chronic Lymphocytic Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 9-9
Author(s):  
Shanye Yin ◽  
Gregory Lazarian ◽  
Elisa Ten Hacken ◽  
Tomasz Sewastianik ◽  
Satyen Gohil ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chronic Lymphocytic Leukemia ◽  
Dna Binding ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Lymphocytic Leukemia ◽  
Advisory Committees ◽  
Bcr Signaling ◽  
Experimental Group

A hotspot mutation within the DNA-binding domain of IKZF3 (IKZF3-L162R) has been identified as a putative driver in chronic lymphocytic leukemia (CLL); however, its functional effects are unknown. We recently confirmed its role as a CLL driver in a B cell-restricted conditional knock-in model. IKZF3 mutation altered mature B cell development and signaling capacity, and induced CLL-like disease in elderly mice (~40% penetrance). Moreover, we found IKZF3-L162R acts as a gain-of-function mutation, altering DNA binding specificity and target selection of IKZF3, and resulting in overexpression of multiple B-cell receptor (BCR) genes. Consistent with the murine data, RNA-sequencing analysis showed that human CLL cells with mut-IKZF3 [n=4] have an enhanced signature of BCR-signaling gene expression compared to WT-IKZF3 [n=6, all IGHV unmutated] (p<0.001), and also exhibited general upregulation of key BCR-signaling regulators. These results confirm the role of IKZF3 as a master regulator of BCR-signaling gene expression, with the mutation contributing to overexpression of these genes. While mutation in IKZF3 has a clear functional impact on a cardinal CLL-associated pathway, such as BCR signaling, we note that this driver occurs only at low frequency in patients (~3%). Because somatic mutation represents but one mechanism by which a driver can alter a cellular pathway, we examined whether aberrant expression of IKZF3 could also yield differences in BCR-signaling gene expression. We have observed expression of the IKZF3 gene to be variably dysregulated amongst CLL patients through re-analysis of transcriptomic data from two independent cohorts of human CLL (DFCI, Landau et al., 2014; ICGC, Ferreira et al., 2014). We thus examined IKZF3 expression and BCR-signaling gene expression, or the 'BCR score' (calculated as the mean expression of 75 BCR signaling-associate genes) in those cohorts (DFCI cohort, n=107; ICGC cohort, n=274). Strikingly, CLL cells with higher IKZF3 expression (defined as greater than median expression) had higher BCR scores than those with lower IKZF3 expression (<median) (p=0.0015 and p<0.0001, respectively). These findings were consistent with the notion that IKZF3 may act as a broad regulator of BCR signaling genes, and that IKZF3 overexpression, like IKZF3 mutation, may provide fitness advantage. In support of this notion, our re-analysis of a gene expression dataset of 107 CLL samples (Herold Leukemia 2011) revealed that higher IKZF3 expression associated with poorer prognosis and worse overall survival (P=0.035). We previously reported that CLL cells with IKZF3 mutation appeared to increase in cancer cell fraction (CCF) with resistance to fludarabine-based chemotherapy (Landau Nature 2015). Instances of increase in mut-IKZF3 CCF upon treatment with the BCR-signaling inhibitor ibrutinib have been reported (Ahn ASH 2019). These studies together suggest an association of IKZF3 mutation with increased cellular survival following either chemotherapy or targeted treatment. To examine whether higher expression of IKZF3 was associated with altered sensitivity to ibrutinib, we performed scRNA-seq analysis (10x Genomics) of two previously treatment-naïve patients undergoing ibrutinib therapy (paired samples, baseline vs. Day 220). We analyzed an average of 11,080 cells per patient (2000 genes/cell). Of note, following ibrutinib treatment, remaining CLL cells expressed higher levels of IKZF3 transcript compared to pretreatment baseline (both p<0.0001), whereas no such change was observed in matched T cells (n ranging between 62 to 652 per experimental group, p>0.05), suggesting that cells with high expression of IKZF3 were selected by ibrutinib treatment. Moreover, we showed that ibrutinib treatment resulted in consistent upregulation of BCR-signaling genes (e.g., CD79B, LYN, GRB2, FOS, RAC1, PRKCB and NFKBIA) (n ranging between 362 to 1374 per experimental group, all p<0.0001), which were likewise activated by mutant IKZF3. Altogether, these data imply that IKZF3 mutation or overexpression may influence upregulation of BCR-signaling genes and enhance cellular fitness even during treatment with BCR-signaling inhibitors. We highlight our observation that IKZF3 mutation appears to be phenocopied by elevated IKZF3 expression, and suggest that alterations in mRNA or protein level that mimic genetic mutations could be widespread in human cancers. Disclosures Kipps: Pharmacyclics/ AbbVie, Breast Cancer Research Foundation, MD Anderson Cancer Center, Oncternal Therapeutics, Inc., Specialized Center of Research (SCOR) - The Leukemia and Lymphoma Society (LLS), California Institute for Regenerative Medicine (CIRM): Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech/Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; VelosBio: Research Funding; Oncternal Therapeutics, Inc.: Other: Cirmtuzumab was developed by Thomas J. Kipps in the Thomas J. Kipps laboratory and licensed by the University of California to Oncternal Therapeutics, Inc., which provided stock options and research funding to the Thomas J. Kipps laboratory, Research Funding; Ascerta/AstraZeneca, Celgene, Genentech/F. Hoffmann-La Roche, Gilead, Janssen, Loxo Oncology, Octernal Therapeutics, Pharmacyclics/AbbVie, TG Therapeutics, VelosBio, and Verastem: Membership on an entity's Board of Directors or advisory committees. Wu:BionTech: Current equity holder in publicly-traded company; Pharmacyclics: Research Funding.

scholarly journals Chronic Lymphocytic Leukemia B Cells Display IgM and IgD Isotype-Restricted Features That Affect Association with Co-Receptors, BCR Signaling, and Leukemic B-Cell Growth In Vivo

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3124-3124
Author(s):  
Andrea Nicola Mazzarello ◽  
Marcus Dühren-von Minden ◽  
Eva Gentner ◽  
Palash Chandra Maity ◽  
Gerardo Ferrer ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Board Of Directors ◽  
Cell Size ◽  
Metabolic Activity ◽  
Research Funding ◽  
Lymphocytic Leukemia ◽  
Advisory Committees ◽  
Bcr Signaling

Abstract The leukemic cells in patients with chronic lymphocytic leukemia (CLL) are highly dependent on B-cell receptor (BCR) mediated signaling. Despite this and the fact that >90% of CLL clones co-express IgM and IgD, the composition and molecular mechanisms regulating BCR signaling regarding the two isotypes and the co-receptors with which they associate is lacking. Here we have addressed these issues. First, using Imaging Flow Cytometry, we evaluated BCR organization on the surface membrane of CLL cells from 11 patients who had participated in a 2H2O-labeling study that determined in vivoCLL B-cell birth rates (BR). We found that in all cases mIgM resided in more and larger surface clusters than mIgD. Also, a statistically significant, direct correlation was observed for IgM density and in vivoCLL-cell BR, with patients exhibiting more recently-divided cells having the highest expression of IgM. This was not the case for IgD. BCR signaling requires co-receptors that can co-localize differently with the two isotypes. Thus, we tested co-localization of stimulatory (CD20) and inhibitory (CD22) co-receptors with mIgM and mIgD, using the proximity ligation assay technique that discriminates 10 to 40 nm distances. Higher IgM:CD20 and lower IgD:CD20 co-localization ratios directly associated with in vivo BR. Conversely, patients whose CLL B cells showed greater IgM to CD22 co-localization ratios had lower BRs. Thus, association of IgM with stimulatory versus inhibitory co-receptors correlated with positive or negative regulation of CLL growth in vivo. Next, we questioned the extent that the observed differences in BCR organization affected the entire clone by measuring a marker of single cell metabolic activity - cell size. IgM and BR associated with entire clonal populations that were skewed toward larger, more active cells. Similarly, high BR CLLs displayed an increased mitochondrial maximal respiration and glycolytic activity and capacity, based on measurements of oxygen consumption rate and extracellular acidification rate, respectively. Since our findings supported a link between IgM- but not IgD-BCRs, growth rate in vivoand clonal metabolic activity, we questioned whether intrinsic, constitutive CLL BCR autonomous signaling differed for these two isotypes. To address this, we examined the signaling capacities of CLL-derived BCRs expressed as IgM or IgD isotypes, while maintaining the original IGHV-D-J and IGLV-J rearrangements. We used B cells that do not express endogenous BCR-related molecules but do express an inducible ERT2- SLP-65 fusion protein which enables examining Ca++influx. All BCRs expressed as IgM effectively mobilized Ca++ without need for an external ligand, indicating autonomous signaling. In contrast, BCRs expressed as IgD did not signal autonomously but required crosslinking with anti-BCR. Thus, only mIgM BCRs naturally transduce a signal in the absence of antigen. To determine the extent that BCR signaling influences clonal activity and in vivoBR, we compared cell size of CLL B cells taken from patients before and after 4 weeks of treatment with the Bruton's tyrosine kinase (BTK) inhibitor, ibrutinib (iBTK). Ibrutinib had a strong treatment effect on cell activity, reducing overall cell size in 10/11 patients. A comparison of single cell areas for patients with lower (BR = 0.54%) and higher (BR = 1.42%) BRs showed an overall reduction of the median cell size for both cases. Thus, iBTK treatment leads to an equilibration of the cell size profile among the cases differing in BR, indicating that ibrutinib acts proportionally more potently on more metabolically active CLL B cells. Likewise, these findings are consistent with BCR signaling, transduced through BTK, being responsible for the increased cellular activity of aggressive CLL clones. In conclusion, increased mIgM density and proximity of mIgM to stimulatory receptors is linked to greater metabolic activity clones and increased rate of proliferationin vivo. Conversely, proximity of mIgM to inhibitory receptors has the opposite correlations.Moreover, only mIgM carries out autonomous signaling, providing another biologic trait linking all these features. Thus, our data support a tight, isotype-dependent regulation of BCR signaling and its consequences for CLL B cells. Further understanding these mechanisms should help generate novel therapies to modify the quality of BCR-transduced signaling and thus cell fate. Disclosures Barrientos: Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees. Rai:Cellectis: Membership on an entity's Board of Directors or advisory committees; Roche/Genentech: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees. Chiorazzi:AR Pharma: Equity Ownership; Janssen, Inc: Consultancy.

scholarly journals Subcutaneous Epcoritamab in Combination with R-CHOP in Patients with Previously Untreated High-Risk Diffuse Large B-Cell Lymphoma: Preliminary Results from a Phase 1/2 Trial

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1413-1413
Author(s):  
David Belada ◽  
Jacob Haaber Christensen ◽  
Kristina Drott ◽  
Sylvia Snauwaert ◽  
Joshua Brody ◽  
...  
Keyword(s):  
High Risk ◽  
B Cell ◽  
Board Of Directors ◽  
Dose Escalation ◽  
Research Funding ◽  
Metabolic Response ◽  
Phase 1 ◽  
B Cell Lymphoma ◽  
Advisory Committees ◽  
Grade 3

Abstract Background: In patients (pts) with newly diagnosed diffuse large B-cell lymphoma (DLBCL) that is considered high risk (revised International Prognostic Index [R-IPI]: 3-5), standard treatment with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is associated with a 4-year overall survival rate of 55% (Sehn et al, Blood 2007). Epcoritamab (DuoBody ®-CD3×CD20) is a subcutaneously administered bispecific antibody that simultaneously binds to CD3 on T cells and CD20 on malignant B cells to induce T-cell-mediated killing. Single-agent epcoritamab demonstrated a manageable safety profile and substantial antitumor activity in pts with heavily pretreated B-cell non-Hodgkin lymphoma (NHL) in the first-in-human phase 1/2 trial (EPCORE NHL-1; NCT03625037). Among pts with relapsed/refractory DLBCL treated at the identified recommended phase 2 dose (RP2D) of 48 mg (n=8), the overall response rate was 88% and the complete response rate was 38% (Hutchings, Lancet, in press). These encouraging data supported initiation of the EPCORE NHL-2 phase 1/2 trial (NCT04663347), which is evaluating epcoritamab in combination with various standard of care therapies in pts with B-cell NHL. We present data from arm 1 of this trial, in which epcoritamab in combination with R-CHOP is evaluated in pts with previously untreated high-risk DLBCL. Methods: Adults with previously untreated DLBCL and an R-IPI score ≥3 received flat-dose epcoritamab in combination with standard R-CHOP for 6 cycles followed by epcoritamab monotherapy. The study includes a dose-escalation cohort (epcoritamab doses: dose level 1 = 24 mg; dose level 2 = 48 mg). Step-up dosing of epcoritamab (ie, priming and intermediate doses before first full dose) and corticosteroid prophylaxis were used as previously described (Hutchings, Lancet, in press) to mitigate cytokine release syndrome (CRS). Tumor response was evaluated by positron emission tomography-computed tomography obtained once every 6 weeks for the first 24 weeks. Results: As of July 15, 2021, 9 pts have been treated with the combination of epcoritamab + R-CHOP (4 with epcoritamab 24 mg; 5 with 48 mg). Median age was 66 years (range, 56-78). All pts had stage III-IV disease. At data cutoff, all pts remained on treatment with a median follow-up of 12.2 weeks (range, 2.2-28.2). The most common treatment-emergent adverse events were CRS (56%; all grade 1/2), anemia (56%; grade 1-3), neutropenia (44%; all grade 3/4), fatigue (33%; all grade 1/2), and peripheral neuropathy (33%; all grade 1/2). Notably, no grade ≥3 CRS events or cases of febrile neutropenia were reported. No dose-limiting toxicities have been observed. Four pts have had ≥1 response assessment, with 3 achieving complete metabolic response (CMR; all in the epcoritamab 24 mg dose-escalation cohort) and 1 pt achieving partial metabolic response (epcoritamab 48 mg cohort) by week 6; 2 of the 3 pts with CMR had response assessments at 6 months, and both remained in CMR at that time. Both dose cohorts have been cleared by the Dose Escalation Committee and Safety Committee, and the expansion part has been opened to enroll additional pts. Conclusions: These preliminary data from a small number of pts suggest that epcoritamab in combination with R-CHOP has a manageable safety profile with no new safety signals. Adverse events were similar to those previously reported for epcoritamab and R-CHOP individually. All evaluable pts achieved early responses, and all pts remain on treatment. Updated and additional data from pts treated in the expansion phase will be presented. These findings warrant further evaluation of epcoritamab for the treatment of high-risk, newly diagnosed DLBCL. Disclosures Belada: Genmab: Research Funding. Drott: Roche: Honoraria; Kyowa Kirin: Honoraria; Respiratorius AB: Membership on an entity's Board of Directors or advisory committees. Narkhede: TG Therapeautics: Research Funding; Genmab: Other: Medical writing support, Research Funding; Genentech/Roche: Research Funding; Gilead: Research Funding. Elliot: Genmab: Current Employment, Patents & Royalties: P158-US-PSP3 . Liu: Genmab: Current Employment. Cota Stirner: AbbVie: Current Employment. Abbas: Genmab: Current Employment. Falchi: Abbvie: Consultancy, Research Funding; Genmab: Consultancy, Research Funding; Roche: Research Funding; Genetech: Research Funding. Clausen: Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel expences ASH 2019; Gilead: Consultancy, Other: Travel expences 15th ICML ; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees.

scholarly journals A Novel Approach to Identify a Putative Leukemia Stem Cell Population in Acute Lymphocytic Leukemia (ALL) and Distinguish Philadelphia Chromosome-Positive ALL from Lymphoid Blast Crisis Chronic Myeloid Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2912-2912
Author(s):  
Jonathan M. Gerber ◽  
Lawrence J. Druhan ◽  
David Foureau ◽  
Elizabeth Jandrisevits ◽  
Amanda Lance ◽  
...  
Keyword(s):  
B Cell ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Blast Crisis ◽  
Philadelphia Chromosome ◽  
Chronic Phase ◽  
Lymphocytic Leukemia ◽  
Aldh Activity ◽  
Advisory Committees

Abstract Introduction: Recent evidence supports the clinical significance of leukemia stem cells (LSCs) in acute myeloid leukemia (AML). However, the identification of LSCs in acute lymphocytic leukemia (ALL) has proved challenging, as transplantation studies in immunocompromised mice have yielded conflicting results. The distinction between Philadelphia chromosome-positive (Ph+) ALL and lymphoid blast crisis (LBC) chronic myeloid leukemia (CML) is also controversial. We previously identified a clinically relevant CD34+CD38- population of LSCs with intermediate (int) levels of aldehyde dehydrogenase (ALDH) activity (CD34+CD38-ALDHint) in AML [Gerber, et al. Blood, 2012]. This population was not present in healthy controls and could be distinguished from normal hematopoietic stem cells (HSCs), which had higher levels of ALDH activity (CD34+CD38-ALDHhigh). We hypothesized that the same approach could be used to identify a putative LSC population in ALL. Furthermore, in contrast to most cases of AML, the chronic phase CML stem cell was found to reside in the same CD34+CD38-ALDHhigh population as normal HSCs [Gerber, et al. Am J Hematol, 2011]. We therefore also hypothesized that the presence of BCR/ABL mutations in the CD34+CD38-ALDHhigh population might help distinguish LBC CML from Ph+ ALL. Methods: Bone marrow and/or peripheral blood specimens were collected at diagnosis from patients with B cell ALL or LBC CML on an IRB-approved protocol. A total of 7 patients were evaluated: 2 Ph- ALL, 2 Ph+ ALL, and 3 LBC CML patients. CD34+ cells were isolated by magnetic bead and column selection, then analyzed by flow cytometry with respect to CD38 expression and ALDH activity. Sorted cell populations were analyzed by fluorescence in situ hybridization (FISH) for leukemia-specific abnormalities. Polymerase chain reaction was performed on clinical samples to determine the presence of a p190 vs. p210 transcript. Results: All patients harbored an aberrant CD34+CD38-ALDHint population, similar to that previously seen in AML. This population was ≥95% positive for BCR/ABL by FISH in all Ph+ ALL and LBC CML cases. It was similarly positive (≥75%) for other leukemia-specific FISH abnormalities (including trisomy 4, 8, 10, 12, and/or 21) in all four ALL cases, as well as one LBC CML case. Conversely, the CD34+CD38-ALDHhigh population (which typically contains the normal HSCs) lacked any of the other cytogenetic abnormalities in all of the cases, irrespective of Ph status or a diagnosis of ALL vs. CML. Notably, the CD34+CD38-ALDHhigh population was negative for BCR/ABL in the Ph+ ALL cases but was >95% positive for BCR/ABL by FISH in the LBC CML cases. The B cell differentiation marker, CD19, was expressed on the CD34+CD38-ALDHint but not the CD34+CD38-ALDHhigh population in all ALL cases, both Ph- and Ph+. In contrast, CD19 expression was variable in the LBC CML cases. Both Ph+ ALL cases possessed a p190 BCR/ABL transcript, whereas all of the LBC CML cases contained a p210 transcript. Also of note, the CD34+CD38-ALDHint population was persistently detectable in one of the LBC CML patients while in complete remission after induction therapy; that patient subsequently relapsed. Conclusions: An abnormal CD34+CD38-ALDHint population was identified in all cases of B cell ALL and LBC CML. This population is analogous to a previously identified, clinically relevant LSC population in AML and may represent a putative LSC population in ALL. The CD34+CD38-ALDHhigh population was normal by FISH in the ALL cases but contained the BCR/ABL mutation in the LBC CML cases, thus permitting distinction between Ph+ ALL and LBC CML (which also differed based on the presence of p190 vs. p210 transcripts, respectively). Additionally, clonal evolution from chronic phase to lymphoid blast crisis CML was apparent, based on the acquisition of additional cytogenetic abnormalities unique to the CD34+CD38-ALDHint population as compared to the CD34+CD38-ALDHhigh population. The presence of CD19 on the putative LSCs in the four cases of ALL suggest that CD19-directed therapies may target the LSCs and thus may have curative potential in those cases. This assay may serve as a means to evaluate other possible therapeutic targets. Lastly, the detection of the abnormal CD34+CD38-ALDHint population may have utility as a minimal residual disease assay for monitoring response to treatment. These findings warrant validation in a larger patient cohort. Disclosures Gerber: Janssen: Research Funding; Alexion: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Grunwald:Alexion: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Medtronic: Equity Ownership; Janssen: Research Funding; Ariad: Membership on an entity's Board of Directors or advisory committees; Forma Therapeutics: Research Funding. Avalos:Seattle Genetics: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Axl Regulates Fibroblast Growth Factor Receptor Signaling in B-Cell Chronic Lymphocytic Leukemia: Dual Targeting in CLL Therapy

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 831-831
Author(s):  
Sutapa Sinha ◽  
Justin Boysen ◽  
Charla Secreto ◽  
Steven L. Warner ◽  
Neil E. Kay ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Lymphocytic Leukemia ◽  
Advisory Committees ◽  
High Affinity ◽  
Fgfr Signaling ◽  
Cell Chronic Lymphocytic Leukemia

Abstract B-cell chronic lymphocytic leukemia (CLL) is an incurable disease and represents a significant health problem in the western world. We and others have reported that primary CLL B-cells spontaneously produce increased levels of proangiogenic basic fibroblast growth factor (bFGF) in vitro and that most CLL plasma contains elevated levels of bFGF. However, the precise role of bFGF in CLL pathobiology is not clearly understood. In this study we investigated the functional implication of the FGF/FGF receptor (FGFR) signaling axis in CLL B-cell biology. We have detected expression of FGFR1 and FGFR3 with comparatively higher levels of the latter receptor tyrosine kinase (RTK), but no or notably low levels of FGFR2/FGFR4, by flow cytometry and Western blot analyses in primary CLL B-cells. This observation was further supported by detection of FGFR1/FGFR3 transcripts in CLL B-cells by semi-quantitative reverse transcriptase polymerase chain reaction. Although both FGFR1 and FGFR3 in CLL B-cells remain as constitutively phosphorylated, we found significantly higher levels of phosphorylation on FGFR3 and thus this latter receptor is likely the predominant RTK of the FGFR family in these leukemic B-cells. Of note, in vitro stimulation of FGFRs with recombinant bFGF was unable to increase total phosphorylation on FGFRs from their constitutive basal levels in CLL B-cells. Further analysis using a bFGF neutralizing antibody suggested that FGFR phosphorylation in CLL B-cells is likely independent of bFGF ligation. We then interrogated the mechanism of how FGFRs were being phosphorylated and/or maintained at the observed constitutive levels of phosphorylation in CLL B-cells. Our previous studies established that Axl is a critical RTK in CLL B-cells since it acts as a docking site for multiple cellular kinases/lipase, an observation supported by earlier literatures in human malignancies. Given this, Axl is likely capable of cross talk with other RTKs including FGFRs to regulate FGFR-signaling in CLL B-cells. Therefore, in an effort to determine whether Axl is functionally associated with FGFR, we examined if these two RTKs exist in the same molecular complex in CLL B-cells. Indeed, immunoprecipitation assays demonstrated that Axl formed a complex with FGFR3 in CLL B-cells, suggesting that Axl is likely functionally linked to the FGFR signaling. In this regard we found that Axl inhibition, using a high-affinity Axl inhibitor (TP-0903; Tolero Pharmaceuticals), resulted in significant reduction of total FGFR phosphorylation in CLL B-cells. Additionally, siRNA-mediated partial depletion of Axl in CLL B-cells reduced total FGFR phosphorylation. In contrast, inhibition of FGFR phosphorylation using a high-affinity FGFR inhibitor could not alter phosphorylation levels on Axl RTK in CLL B-cells. Together, these findings suggest that Axl has a dominant role in the regulation of FGFR signaling in CLL B-cells. To find out if inhibition of FGFR can induce apoptosis in CLL B-cells we used a specific inhibitor for FGFR (TKI-258; Novartis) to treat CLL B-cells. Here we found a substantial level of apoptosis induction in the leukemic B-cells with a mean LD50 dose of ~2.5 μM. Interestingly, Axl inhibition by TP-0903 induced a robust level of apoptosis in CLL B-cells in the nanomolar dose range with a mean LD50 dose of 0.14 mM. Thus Axl inhibition exerts a very robust cytotoxic effect on CLL B-cell survival likely targeting both Axl and FGFR signaling pathways via Axl inhibition. In conclusion, we have detected expression of constitutively active FGFR1 and 3 in primary CLL B-cells and that inhibition of FGFR signaling induces considerable levels of CLL B-cell apoptosis albeit lower than that observed on Axl RTK inhibition. Interestingly, our findings here suggest that Axl forms an active RTK complex with FGFR and that Axl inhibition modifies FGFR phosphorylation levels. Thus it is likely that Axl RTK can regulate FGFR signaling in the CLL B-cells. In total these observations suggest that the finding of robust induction of apoptosis in CLL B-cells is as a result of targeting two signaling pathways with Axl inhibition: Axl and FGFR. These studies further support investigation of Axl inhibition as a way to develop a more effective and efficient therapeutic intervention for CLL patients. Disclosures Warner: Tolero Pharmaceuticals: Employment, Equity Ownership, Patents & Royalties. Kay:Genetech: Research Funding; Pharmacyclics: Research Funding; Hospira: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Clinical Characteristics and Outcomes of Chronic Lymphocytic Leukemia Patients with Richter Transformation

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1857-1857
Author(s):  
Yucai Wang ◽  
Marcella Tschautscher ◽  
Kari G. Chaffee ◽  
Timothy G. Call ◽  
Jose F. Leis ◽  
...  
Keyword(s):  
B Cell ◽  
Board Of Directors ◽  
High Intensity ◽  
Research Funding ◽  
Clinical Characteristics ◽  
B Cell Lymphoma ◽  
Lymphocytic Leukemia ◽  
Novel Agents ◽  
First Line ◽  
Advisory Committees

Abstract Introduction: Richter transformation (RT) refers to transformation of chronic lymphocytic leukemia (CLL) to an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL). Most studies on the management of RT were either small retrospective series or early phase non-randomized trials before the era of novel agents. The natural history, prognostication and optimal treatment of patients with RT remain undefined. Here we report the clinical characteristics and outcomes of a large series of RT from a single center. Methods: Biopsy-confirmed RT (limited to non-Hodgkin lymphoma) diagnosed from 4/1993 to 4/2018 were identified from the Mayo Clinic CLL database. Clinical characteristics, treatment information and follow-up data were abstracted by chart review. Overall survival (OS) was defined as time from RT diagnosis to death from any cause and analyzed using the Kaplan-Meier method. Statistical analysis was done in SAS 9.4. Results: A total of 204 patients with CLL who developed RT were identified. The median age at CLL diagnosis was 62 years (range 22-85), and 148 (73%) were male. The median time to transformation was 4.7 years (range 0-34.5). Prior to RT, 68 (33.3%) patients received no treatment for CLL, 109 (53.4%) received chemoimmunotherapy (CIT) only, and 27 (13.2%) received at least one novel agent (idelalisib, ibrutinib, or venetoclax) for CLL. The median lines of CLL therapy prior to RT was 2 (range 0-13). The median age at RT diagnosis was 69 years (range 30-88). Pathology of RT was DLBCL and high grade B-cell lymphoma in 193 (94.6%) and 11 (5.4%) patients, respectively. The median LDH was 306 IU/L (range 99-9000). 62/125 (49.6%) patients had bulky disease (≥ 5 cm), and the median PET SUVmax was 13.9 (range 2.9-30.0). 45/131 (34.4%) patients had del(17p) or TP53 mutation, 12 (9.2%) had del(11q), 21 (16.0%) had trisomy 12, 27 (20.6%) had del(13q), and 25 (19.1%) had normal FISH. The CLL and RT were clonally related in 12/21 (57.1%) patients. For the transformed lymphoma, cell of origin by Han's algorithm was germinal center B cell-like (GCB) and non-GCB in 31/100 (31.0%) and 69/100 (69.0%) patients, respectively. EBV was positive in 14/52 (26.9%) patients. The median Ki-67 was 80% (range 10-100). Myc and Bcl-2 were positive by IHC in 31/43 (72.1%) and 83/103 (80.6%) patients, respectively; 27/56 (48.2%) were double-expressors. MYC, BCL2, and BCL6 rearrangement was positive by FISH in 18/68 (26.5%), 10/34 (29.4%), and 4/31 (12.9%) patients, respectively; 8/66 (12.1%) were double/triple-hit. The most common first-line treatment (Table 1 notes) of RT was R-CHOP-like regimen (n=114, 65.5%). Other treatments included R-EPOCH-like (n=6, 3.4%), high-intensity chemotherapy (n=15, 8.6%), novel agents (eg, ibrutinib, venetoclax, pembrolizumab; n=19, 10.9%), other chemotherapy (n=12, 6.9%), and palliative therapy (n=8, 4.6%). Response to first-line treatment was CR in 57 (38.0%), PR in 33 (22.0%), SD in 18 (12.0%), and PD in 42 (28.0%) patients. The median OS of the entire cohort after RT diagnosis was 12.0 months. The median OS for patients who received no prior CLL treatment, CIT only or at least one novel agent for CLL were 65.5, 7.3, and 12.0 months, respectively (P<0.0001; Figure 1). Of note, in patients who received CIT only for CLL, ~10% and 60% received high-intensity and R-CHOP/R-EPOCH-like chemotherapy, respectively, as first-line RT therapy. In contrast, in patients who had prior novel agents for CLL, 56% and 26% were treated with novel agents and R-CHOP/R-EPOCH-like chemotherapy, respectively, as first-line RT therapy. Patients with or without del(17p)/TP53 mutation had a median OS of 8.3 and 12.8 months, respectively (P=0.046). Patients who were treated with high intensity chemotherapy, R-CHOP/R-EPOCH-like regimens, novel agents, and other therapies for RT had a median OS of 35.1, 14.4, 10.9 and 6.1 months, respectively (P=0.02; Figure 2). OS comparisons by CLL/RT clonal relationship, double expressor or double/triple-hit status are shown in Table 1, with no significant differences noted. Conclusions: Over two thirds of RT were the non-GCB subtype, and about half were Myc/Bcl-2 double expressors. Patients who developed RT without prior CLL therapies had a significantly better OS. In contrast, patients who had received prior CLL therapies had poor outcomes. Myc/Bcl-2 double expressor and MYC/BCL2/BCL6 double/triple hit status had no impact on OS. Disclosures Kenderian: Humanigen: Research Funding; Novartis: Patents & Royalties; Tolero Pharmaceuticals: Research Funding. Kay:Infinity Pharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Acerta: Research Funding; Cytomx Therapeutics: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees. Parikh:Janssen: Research Funding; Abbvie: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; MorphoSys: Research Funding; Gilead: Honoraria; Pharmacyclics: Honoraria, Research Funding. Ding:Merck: Research Funding.

scholarly journals A Phase 1 Study of NKX019, a CD19 Chimeric Antigen Receptor Natural Killer (CAR NK) Cell Therapy, in Subjects with B-Cell Malignancies

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3868-3868
Author(s):  
Michael Dickinson ◽  
Nada Hamad ◽  
Christian E Bryant ◽  
Gautam Borthakur ◽  
Chitra Hosing ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Nk Cells ◽  
Board Of Directors ◽  
Research Funding ◽  
Phase 1 ◽  
Publicly Traded ◽  
Phase 1 Study ◽  
Advisory Committees ◽  
Car T

Abstract Background: B-cell lineage cancers are a worldwide healthcare burden. Over 500,000 new cases of non-Hodgkin lymphoma (NHL) and 50,000 new cases of acute lymphoblastic leukemia (ALL) are diagnosed world-wide each year (seer.cancer.gov, Smith 2015, Solomon 2017). Despite progress in treatment, many patients diagnosed with this heterogeneous group of cancers still succumb to their disease. Recently approved autologous chimeric antigen receptor (CAR) T cells specific for CD19 have altered the treatment landscape for some patients with relapsed or refractory (R/R) B-cell malignancies, though significant toxicities associated with T-cell expansion and the necessity for bespoke manufacturing have limited their use. Natural killer (NK) cells, part of the innate immune system, efficiently recognize transformed cells and are particularly suited to address limitations of the approved CAR T products (Marcus 2014, Morvan 2016). Lacking a T-cell receptor and the consequent clonal expansion, non-engineered NK cells have been safely administered after lymphodepletion without side effects typically associated with T-cell therapies, such as severe cytokine release syndrome or neurotoxicity (Bachier 2020). Allogeneic NK cell-based therapies allow off-the-shelf use, obviating the necessity to wait for manufacture of autologous T-cell therapies. CD19-directed CAR NK cells have been administered safely, with promising preliminary efficacy (Liu 2020). NKX019 is a cryopreserved product, composed of expanded NK cells engineered to express a humanized CAR against CD19, fused to co-stimulatory (OX40) and signaling (CD3ζ) domains to enhance their intrinsic antitumor activity. NKX019 also expresses a membrane-bound interleukin-15 (IL-15) to serve as an autocrine growth factor and thereby increase NKX019 persistence, with an in vivo half-life of over up to 28 days without systemic IL-2 support. Preclinical characterization has shown that NKX019 cells are 10 times more effective at killing CD19+ target cells than non-engineered NK cells, resulting in greater suppression of xenograft tumor models (Morisot 2020). Further, NKX019, unlike CD19 CAR T cells, retained cytotoxicity even when CD19 antigen density was reduced &gt;50x on target cells. Hence, clinical evaluation of NKX019 is being undertaken in this Phase 1 study in subjects with R/R NHL or ALL. Methods: This is a multicenter, open-label, Phase 1 study of NKX019 (Figure). The study will be conducted in 2 parts: Part 1 (dose finding) to determine the recommended Phase 2 dose (RP2D) of NKX019 separately in adult patients with CAR T naïve R/R NHL or B-ALL, utilizing a "3+3" enrollment schema. Part 2 (dose expansion) will further evaluate safety and tolerability, pharmacokinetics (PK), immunogenicity, pharmacodynamics (PDn), and antitumor activity of NKX019 using RP2D with separate expansion cohorts for patients with ALL as well as different subtypes of NHL, including a cohort of CAR T pretreated large B-cell lymphoma. NKX019 is being manufactured from NK cells obtained from healthy adult donors. The study evaluates two dose levels of NKX019: 3 × 10 8 and 1 × 10 9 viable CAR+ NK cells. NKX019 will be administered on Days 0, 7, and 14 of a 28-day cycle following standard fludarabine/cyclophosphamide lymphodepletion (Table). Up to 5 total cycles may be administered based on response and tolerability assessed at the end of each cycle. The primary endpoint is incidence of adverse events, dose-limiting toxicities, clinically significant laboratory abnormalities, and determination of the RP2D. Secondary endpoints include evaluation of standard cellular PK parameters, PDn, immunogenicity, and antitumor responses. Subjects will be assessed for efficacy using disease-specific criteria: Lugano classification with LYRIC refinement for pseudo-progression (NHL), 2018 International Workshop (IW) criteria (CLL), 6th IW criteria (Waldenström macroglobulinemia [WM]), and National Comprehensive Cancer Version 1.2020 (B-ALL) (Cheson 2006, Cheson 2014, Hallek 2018, Owen 2013, Brown 2020). Enrollment across multiple sites in the US and Australia is expected to start in the second half of 2021. Figure 1 Figure 1. Disclosures Dickinson: Celgene: Research Funding; Gilead Sciences: Consultancy, Honoraria, Speakers Bureau; MSD: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Takeda: Research Funding; Amgen: Honoraria; Roche: Consultancy, Honoraria, Other: travel, accommodation, expenses, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau. Hamad: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Bryant: Jansen, BMS/Celgene, Skyline Diagnostics: Consultancy; Amgen: Honoraria. Borthakur: Astex: Research Funding; University of Texas MD Anderson Cancer Center: Current Employment; Protagonist: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy; Ryvu: Research Funding; ArgenX: Membership on an entity's Board of Directors or advisory committees. Hosing: Nkarta Therapeutics: Membership on an entity's Board of Directors or advisory committees. Shook: Nkarta Therapeutics: Current Employment, Current equity holder in publicly-traded company. Tan: Nkarta Therapeutics: Current Employment, Current equity holder in publicly-traded company. Rajangam: Nkarta Therapeutics: Current Employment, Current equity holder in publicly-traded company. Liu: SITC: Honoraria; BMS; Karyopharm; Miltenyi: Research Funding; Agios; NGM Biopharmaceuticals; BeiGene: Consultancy. McSweeney: Kite-Gilead: Consultancy; Kite-Gilead, Autolus, Novartis: Research Funding; Kite-Gilead: Honoraria, Speakers Bureau. Hill: Novartis: Consultancy, Honoraria, Research Funding; Epizyme: Consultancy, Honoraria; AstraZenica: Consultancy, Honoraria; Beigene: Consultancy, Honoraria, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel Support, Research Funding; Pfizer: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria, Research Funding; Incyte/Morphysis: Consultancy, Honoraria, Research Funding; Gentenech: Consultancy, Honoraria, Research Funding; Celgene (BMS): Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding.

scholarly journals B-Cell Receptor Signaling Drives Glycolysis in Chronic Lymphocytic Leukemia Cells

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3121-3121
Author(s):  
Andrew James Clear ◽  
Annalisa D'Avola ◽  
Samir G. Agrawal ◽  
Laura Z. Rassenti ◽  
Thomas J. Kipps ◽  
...  
Keyword(s):  
B Cells ◽  
Glucose Uptake ◽  
Board Of Directors ◽  
Research Funding ◽  
Aerobic Glycolysis ◽  
Lymphocytic Leukemia ◽  
Advisory Committees ◽  
Mitochondrial Mass ◽  
Bcr Signaling ◽  
The Impact

Abstract A key feature of tumor cell energetics is preferential metabolism of glucose to lactate even in the presence of oxygen (aerobic glycolysis). While this is an inefficient way of producing energy, it enables cancer cells to use glucose to generate biomass to support cellular proliferation. It is unclear whether this process is playing a role in the pathogenesis of chronic lymphocytic leukemia (CLL). Previous studies have noted that CLL cells have increased numbers of mitochondria when compared with healthy B cells (Carew Leukaemia 2004, Jitschin Blood 2014). As CLL cells have increased expression of lipoprotein lipase it has been hypothesized that CLL cells adopt a predominantly mitochondrial metabolism. In this study, we investigated the role of metabolism in the pathogenesis of CLL. While initial analysis of mitochondrial mass by flow cytometry showed that CLL cells do have increased mitochondrial content compared to healthy B cells, these and previous observations were comparing a monoclonal population of CLL cells with a CD27+ activated/memory phenotype with polyclonal healthy B cells predominantly composed of naïve CD27- cells. When we investigated this further we found that healthy CD27+ memory B cells have a higher mitochondrial mass when compared with healthy CD27- naïve B cells. CLL cells actually had reduced mitochondrial mass when compared healthy CD27+ memory B cells, which fell further with disease progression. B-cell receptor (BCR) signaling plays a vital role in the pathogenesis of CLL, as shown by the clinical efficacy of inhibitors of this pathway. Despite this little is known regarding the impact of BCR-signaling on CLL-cell metabolism. Primary human CLL cells were stimulated with either anti-IgM, anti-IgD or anti-IgG (isotype control) for up to 72 hours before measuring the residual glucose concentration of the media to assess glucose uptake. Anti-IgM treated CLL cells showed an increase in glucose uptake compared to control. The impact of anti-IgM on the expression of enzymes involved in glycolysis including glucose transporters (GLUTs), hexokinase, phosphofructokinase, enolase, and pyruvate kinase was assessed by immunoblotting. As myc is induced by BCR-signaling in CLL cells we focused on known myc targets hexokinase 2 (HK2), enolase 1 (ENOL-1), lactate dehydrogenase A (LDHA) and the heterogenous nuclear ribonuclearproteins (hnRNPs) A1, A2/B1 and PTBP1. GLUT3, HK2 and the hnRNPs were all expressed at low levels in resting CLL cells but increased significantly (at 24 hours) after anti-IgM stimulation. The other myc targets ENOL-1 and LDHA were constitutively expressed and did not increase further after stimulation. There was significant heterogeneity in response to anti-IgM stimulation with IGHV unmutated cases showing a trend toward greater glucose uptake and enzyme induction, while anti-IgD stimulation had a similar but weaker effect. Immunohistochemistry on lymph node biopsies from CLL patients showed a significant increase in expression of GLUT3 and HK2 within CLL proliferation centres. hnRNP induction has been shown to promote a switch to use of the M2 isoform of pyruvate kinase (PKM2): a key feature of many cancers. Interestingly, both circulating and lymph node CLL cells were already switched to using PKM2 and so anti-IgM stimulation had little further effect. However, when the relative levels of PKM1 and PKM2 were compared between early- and advanced-stage patients there was a significant shift to use of PKM2 with disease progression. Treatment of CLL cells in vitro by ibrutinib, idelalisib and the MEK inhibitor U0126 all blocked the anti-IgM induced increase in glucose uptake and GLUT3, HK2 and hnRNP expression. Investigation of the expression of GLUT3 and HK2 in CLL cells obtained from ibrutinib-treated patients also showed a reduction in the expression of these proteins demonstrating that ibrutinib is metabolically reprogramming CLL cells in vivo. We conclude that previous observations regarding an increase in mitochondrial mass in CLL cells compared to healthy B cells reflects their differentiation states. In contrast, we show that BCR-signaling increases glucose uptake and glycolytic enzyme expression in a myc-dependent manner as part of a switch to aerobic glycolysis. Treatment with BCR inhibitors block this effect. Therefore, we anticipate that many of the novel anti-glycolytic therapies currently in development will prove useful in the treatment of CLL. Disclosures Kipps: F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Verastem: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy; Gilead: Consultancy, Honoraria, Research Funding; Genentech Inc: Consultancy, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Verastem: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Gribben:Acerta Pharma: Honoraria, Research Funding; Novartis: Honoraria; Wellcome Trust: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Abbvie: Honoraria; Kite: Honoraria; TG Therapeutics: Honoraria; Cancer Research UK: Research Funding; Unum: Equity Ownership; Medical Research Council: Research Funding; Janssen: Honoraria, Research Funding; NIH: Research Funding; Roche: Honoraria; Pharmacyclics: Honoraria.

scholarly journals A New Role for the SRC Family Member HCK As a Driver of BCR/SYK Signaling in MYD88 Mutated Lymphomas

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3512-3512
Author(s):  
Manit Munshi ◽  
Xia Liu ◽  
Amanda Kofides ◽  
Nickolas Tsakmaklis ◽  
Maria G Demos ◽  
...  
Keyword(s):  
B Cell ◽  
Family Member ◽  
Board Of Directors ◽  
Research Funding ◽  
Marked Reduction ◽  
Wild Type ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Bcr Signaling ◽  
Survival Signaling

Abstract Activating mutations in MYD88 (MYD88 Mut) are common in B-cell malignancies including Waldenstrom Macroglobulinemia (WM) and ABC subtype of diffuse B-cell lymphoma (ABC DLBCL). MYD88 is a component of the Toll-like receptor (TLR) pathway. We and others previously showed that MYD88 Mut triggers assembly of a "Myddosome" complex that leads to downstream pro-survival signaling that includes IRAK4/IRAK1 and BTK triggered NF-κB (Ngo et al, Nature 2011; Treon et al, NEJM 2012; Yang et al, Blood 2013) and HCK mediated BTK/NF-κB, PI3K/AKT, and MAPK/ERK signaling (Yang et al, Blood 2016; Liu et al Blood Adv. 2020). The activation of the B-cell receptor (BCR) signaling component SYK has also been observed in MYD88 Mut WM (Argyropoulos et al, Leukemia 2016). In ABC DLBCL, chronic active BCR signaling underlies SYK activation that is triggered by the SRC family member LYN (Davis et al, Nature 2010). These observations led us to explore potential drivers of BCR/SYK activation in WM. We previously reported that MYD88 Mut triggered activation of SYK in WM and ABC DLBCL cells (Munshi et al, BCJ 2020). Herein, we investigated if HCK, a SRC family member that is transcriptionally upregulated and activated by MYD88 Mut could trigger the BCR pathway through SYK activation. Since LYN is an integral part of BCR signaling, we first examined its expression and activation state in MYD88 Mut WM and ABC DLBCL cells. While MYD88 Mut TMD8, HBL-1 and OCI-Ly3 ABC DLBCL cells showed strong expression of p-LYN, such expression was absent or low in MYD88 Mut BCWM.1 and MWCL-1 cells, as well as CD19-selected bone marrow derived primary lymphoplasmacytic cells (LPCs) from WM patients. In view of the above findings, we next interrogated a direct role for HCK in mediating SYK activation. We over-expressed wild-type HCK (HCK WT) or gatekeeper mutated HCK (HCK T333M) in MYD88 Mut BCWM.1 and MWCL-1 WM cell lines, and TMD8 ABC DLBCL cells. In all these cell lines, over-expression of HCK WT or HCK T333M triggered a robust increase in phosphorylation of SYK Y525/Y526 in comparison to vector only transduced cells. Moreover, using an inducible vector system, knockdown of HCK showed a marked reduction in phosphorylation of SYK Y525/Y526 in MYD88 Mut BCWM.1 WM and TMD8 ABC DLBCL cells. We next sought to clarify if HCK and activated SYK were present in the same signaling complex. We performed co-immunoprecipitation experiments using an HCK antibody in MYD88 Mut BCWM.1, TMD8 and wild-type MYD88 (MYD88 WT) Ramos cells. The HCK antibody effectively pulled down p-SYK in MYD88 Mut BCWM.1 and TMD8 cells, but not in MYD88 WT Ramos cells. To confirm whether SYK activation was a result of HCK kinase activity, we next performed rescue experiments with the HCK inhibitors A419259 and KIN-8194 in MYD88 Mut BCWM.1 and MWCL-1 WM and TMD8 ABC DLBCL cells expressing either HCK WT or the HCK T333M protein that abrogated the activity of these inhibitors against HCK. Expression of the HCK T333M protein produced marked resistance to A419259 as well as KIN-8194 versus vector or HCK WT transduced BCWM.1 and MWCL-1 cells. By PhosFlow analysis, we observed that expression of HCK T333M but not HCK WT led to persistent activation of HCK and SYK in the presence of A419259 or KIN-8194 in BCWM.1 and MWCL-1 WM cells, and TMD8 ABC DLBCL cells. Consistent with these observations, treatment of primary MYD88 mutated WM LPCs cells with either A419259 or KIN-8194 also showed marked reduction in both p-HCK and p-SYK expression by PhosFlow analysis. Taken together, our findings show that SYK is activated by HCK in MYD88 Mut B-cell lymphomas cells; broaden the pro-survival signaling generated by aberrant HCK expression in response to MYD88 Mut; and help further establish HCK as an important therapeutic target in MYD88 Mut B-cell lymphomas. Disclosures Palomba: Juno: Patents & Royalties; Rheos: Honoraria; Seres: Honoraria, Other: Stock, Patents & Royalties, Research Funding; Notch: Honoraria, Other: Stock; Kite: Consultancy; Novartis: Consultancy; BeiGene: Consultancy; Priothera: Honoraria; Nektar: Honoraria; PCYC: Consultancy; Wolters Kluwer: Patents & Royalties; WindMIL: Honoraria; Magenta: Honoraria; Pluto: Honoraria; Lygenesis: Honoraria; Ceramedix: Honoraria. Castillo: Abbvie: Consultancy, Research Funding; BeiGene: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Janssen: Consultancy; Roche: Consultancy; TG Therapeutics: Research Funding. Gray: Syros, C4, Allorion, Jengu, B2S, Inception, EoCys, Larkspur (board member) and Soltego (board member: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Novartis, Takeda, Astellas, Taiho, Jansen, Kinogen, Arbella, Deerfield and Sanofi: Research Funding. Munshi: Bristol-Myers Squibb: Consultancy; Janssen: Consultancy; Amgen: Consultancy; Celgene: Consultancy; Oncopep: Consultancy, Current equity holder in publicly-traded company, Other: scientific founder, Patents & Royalties; Abbvie: Consultancy; Takeda: Consultancy; Karyopharm: Consultancy; Adaptive Biotechnology: Consultancy; Novartis: Consultancy; Legend: Consultancy; Pfizer: Consultancy. Anderson: Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Millenium-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-Aventis: 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; Pfizer: Membership on an entity's Board of Directors or advisory committees; Scientific Founder of Oncopep and C4 Therapeutics: Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Mana Therapeutics: Membership on an entity's Board of Directors or advisory committees. Yang: Blueprint Medicines Corporations: Current Employment, Current holder of individual stocks in a privately-held company. Treon: BeiGene: Consultancy, Research Funding; Eli Lily: Research Funding; Abbvie/Pharmacyclics: Consultancy, Research Funding.

Sign in / Sign up

Export Citation Format

Share Document