scholarly journals Cross-Talk between Cytokine and NF-ĸb Signaling in the CLL Microenvironment Can Affect Sensitivity for Venetoclax

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5449-5449
Author(s):  
Marco Haselager ◽  
Rachel Thijssen ◽  
Arnon P. Kater ◽  
Eric Eldering
Keyword(s):  
Lymph Node ◽  
Chronic Lymphocytic Leukemia ◽  
Cross Talk ◽  
Binding Sites ◽  
Research Funding ◽  
Time Course ◽  
Lymphocytic Leukemia ◽  
Cytokine Signaling ◽  
T Helper ◽  
Cd40 Stimulation

INTRODUCTION. The Bcl-2 inhibitor Venetoclax provides profound reductions in circulating chronic lymphocytic leukemia (CLL) cells in the majority of patients. However, lymph node (LN) responses are less robust, which may be linked to an acquired resistance imposed by pro-survival signals. Prime among these is CD40 stimulation leading to activation of NF-kB, and induction of Bcl-XL expression1. Bcl-XL is a prime determinant of resistance to Venetoclax2 and regulatory mechanisms of its expression are of clinical significance. Cytokines IL-21 and IL-4 are secreted by T helper cells and abundant in the CLL lymph node microenvironment. Importantly, IL-21 and IL-4 play an important role in CLL survival and proliferation3. In the present study, we investigated how signals from T helper cytokines IL-21 or IL-4 affect Bcl-XL expression as a model for the CLL LN microenvironment, specifically in relation to Venetoclax resistance. RESULTS. Following CD40 stimulation, IL-21 and IL-4 show opposing effects on Bcl-XL expression. Correspondingly, this was associated with CD40-induced resistance to Venetoclax which was augmented by IL-4 and reversed by IL-21. We subsequently investigated the rewiring between CD40 activation, differential cytokine signaling and Bcl-XL expression. IL-21 or IL-4 stimulation correspond with differential STAT3 or -6 phosphorylation and STAT3 and -6 have predicted binding sites near the known p65 and p52 binding sites in the Bcl-XL promoter region. Using reporter assays with Bcl-XL promotor constructs we demonstrate competition (through IL-21-induced STAT3) or synergy (through IL-4 induced-STAT6) with CD40-mediated activation of the NF-kB pathway. By applying in situ proximity ligation (isPLA) in primary CLL cells, we showed direct interaction of both (non-)canonical p65 and p52 with STAT3 and STAT6. Moreover, time-course analyses indicated that STAT3 drives NF-kB out of the nucleus, whereas STAT6 keeps NF-kB inside the nucleus, and this distinction controls Bcl-XL expression. These observations suggest that cross-talk between JAK/STAT signaling and NF-kB signaling happens by direct binding to the Bcl-XL promoter and by limiting NF-kB availability at the Bcl-XL promoter. CONCLUSIONS. These data show that protective signals from the CLL microenvironment can be tipped towards apoptosis sensitivity by interfering with JAK/STAT and NF-kB signaling, providing novel therapeutic clues in case of emerging resistance to targeted drugs such as Venetoclax. 1 J. Tromp, S. Tonino, J. Elias, A. Jaspers, D. Luijks, A. Kater, R. van Lier, M. van Oers, E. Eldering. Dichotomy in NF-kB signaling and chemoresistance in IGHV mutated versus unmutated CLL cells upon CD40/TLR9 triggering. Oncogene 2010. 2 R. Thijssen, E. Slinger, K. Weller, C. Geest, T. Beaumont, M. van Oers, A. Kater, E. Eldering. Resistance to ABT-199 induced by microenvironmental signals in chronic lymphocytic leukemia can be counteracted by CD20 antibodies or kinase inhibitors. Haematologica 2015. 3 C. Schleiss, W. Ilias, O. Tahar, Y. Güler, L. Miguet, C. Mayeur-Rousse, L. Mauvieux, L. Fornecker, E. Toussaint, R. Herbrecht, F. Bertrand. M. Maumy-Bertrand, T. Martin, S. Fournel, P. Georgel, S. Bahram, L. Vallat. BCR-associated factors driving chronic lymphocytic leukemia cells in proliferation ex vivo. Scientific Reports 2019. Disclosures Eldering: Celgene: Research Funding; Roche: Research Funding; Janssen Pharmaceutical Companies: Research Funding.

Differential Noxa/Mcl-1 balance in peripheral versus lymph node chronic lymphocytic leukemia cells correlates with survival capacity

Blood ◽  
2006 ◽  
Vol 109 (4) ◽  
pp. 1660-1668 ◽  
Author(s):  
Laura A. Smit ◽  
Delfine Y.H. Hallaert ◽  
René Spijker ◽  
Bart de Goeij ◽  
Annelieke Jaspers ◽  
...  
Keyword(s):  
Lymph Node ◽  
Chronic Lymphocytic Leukemia ◽  
Lymph Nodes ◽  
Peripheral Blood ◽  
Proteasome Inhibition ◽  
Lymphocytic Leukemia ◽  
Protein Levels ◽  
Cd40 Stimulation ◽  
Apoptosis Gene

Abstract The gradual accumulation of chronic lymphocytic leukemia (B-CLL) cells is presumed to derive from proliferation centers in lymph nodes and bone marrow. To what extent these cells possess the purported antiapoptotic phenotype of peripheral B-CLL cells is unknown. Recently, we have described that, in B-CLL samples from peripheral blood, aberrant apoptosis gene expression was not limited to protective changes but also included increased levels of proapoptotic BH3-only member Noxa. Here, we compare apoptosis gene profiles from peripheral blood B-CLL (n = 15) with lymph node B-CLL (> 90% CD5+/CD19+/CD23+ lymphocytes with Ki67+ centers; n = 9). Apart from expected differences in Survivin and Bcl-xL, a prominent distinction with peripheral B-CLL cells was the decreased averaged level of Noxa in lymph nodes. Mcl-1 protein expression showed a reverse trend. Noxa expression could be reduced also in vitro by CD40 stimulation of peripheral blood B-CLL. Direct manipulation of Noxa protein levels was achieved by proteasome inhibition in B-CLL and via RNAi in model cell lines. In each instance, cell viability was directly linked with Noxa levels. These data indicate that suppression of Noxa in the lymph node environment contributes to the persistence of B-CLL at these sites and suggest that therapeutic targeting of Noxa might be beneficial.

scholarly journals Regulation of Bcl-XL by non-canonical NF-κB in the context of CD40-induced drug resistance in CLL

2021 ◽  
Author(s):  
Marco Haselager ◽  
Rachel Thijssen ◽  
Christopher West ◽  
Louise Young ◽  
Roel Van Kampen ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Lymph Node ◽  
Chronic Lymphocytic Leukemia ◽  
Signaling Pathways ◽  
Lymphocytic Leukemia ◽  
Cd40 Stimulation ◽  
Bh3 Mimetic ◽  
Critical Survival ◽  
Survival Signals

AbstractIn chronic lymphocytic leukemia (CLL), the lymph node (LN) microenvironment delivers critical survival signals by inducing the expression of anti-apoptotic Bcl-2 members Bcl-XL, Bfl-1, and Mcl-1, resulting in apoptosis blockade. We determined previously that resistance against various drugs, among which is the clinically applied BH3 mimetic venetoclax, is dominated by upregulation of the anti-apoptotic regulator Bcl-XL. Direct clinical targeting of Bcl-XL by, e.g., Navitoclax is however not desirable due to induction of thrombocytopenia. Since the actual regulation of Bcl-XL in CLL in the context of the LN microenvironment is not well elucidated, we investigated various candidate LN signals to drive Bcl-XL expression. We found a dominance for NF-κB signaling upon CD40 stimulation, which results in activation of both the canonical and non-canonical NF-κB signaling pathways. We demonstrate that expression of Bcl-XL is first induced by the canonical NF-κB pathway, and subsequently boosted and continued via non-canonical NF-κB signaling through stabilization of NIK. NF-κB subunits p65 and p52 can both bind to the Bcl-XL promoter and activate transcription upon CD40 stimulation. Moreover, canonical NF-κB signaling was correlated with Bfl-1 expression, whereas Mcl-1 in contrast, was not transcriptionally regulated by NF-κB. Finally, we applied a novel compound targeting NIK to selectively inhibit the non-canonical NF-κB pathway and showed that venetoclax-resistant CLL cells were sensitized to venetoclax. In conclusion, protective signals from the CLL microenvironment can be tipped towards apoptosis sensitivity by interfering with non-canonical NF-κB signaling.

scholarly journals Development of a Novel Lymph Node-Based 3D Culture System Promoting Chronic Lymphocytic Leukemia Proliferation and Survival

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 47-48
Author(s):  
Marco Haselager ◽  
Eduard Perelaer ◽  
Arnon P. Kater ◽  
Eric Eldering
Keyword(s):  
Lymph Node ◽  
Chronic Lymphocytic Leukemia ◽  
In Vitro Culture ◽  
Culture System ◽  
Research Funding ◽  
Lymphocytic Leukemia ◽  
2D System

INTRODUCTION. Primary chronic lymphocytic leukemia (CLL) cells, despite originating from a proliferative disease, rapidly undergo apoptosis in vitro in absence of microenvironmental survival signals1. Although co-culture with stromal cells or the addition of soluble factors can increase and extend CLL survival, no system permits the long-term expansion of CLL cells in vitro2. The difficulties of mimicking a physiologic microenvironment supporting CLL cells hinder in vitro studies of proliferation, drug screens and prevent propagation of rare subclones. For other cancers, various types of 3D cultures have been introduced utilizing scaffolds, gels, spheroid cultures and fluidic systems, representing a more accurate representation of the in vivo microenvironment3. Unlike solid tumors, secondary lymphoid tissues where CLL cells proliferate in vivo, do not derive from a single stem cell progenitor. Developing an appropriate 3D in vitro culture system for CLL is of obvious importance and may contribute pathophysiological relevance to study long-term CLL proliferation and more accurate drug screening4,5. Within the field of CLL, attempts have focused on bone marrow stroma, but it may be biologically and clinically more relevant to investigate the lymph node niche as this is the critical site of CLL proliferation6. METHODS. Primary CLL cells were cultured in various 3D systems including hydrogels, hanging drop cultures and ultra-low attachment plates (ULA) plates in parallel to an optimal 2D system, consisting of the culture of primary CLL cells on a monolayer of CD40L-presenting fibroblasts (3T40) or 3T3 negative control fibroblasts. CLL cells were either cultured as PBMCs alone, with or without T cells, or co-cultured with 3T40 or primary lymph node fibroblasts. CLL cells were either stimulated directly with IL-2, IL-15, IL-21 and CpG and/or indirectly via a T cell stimulation of anti-CD3/CD28. RESULTS. After testing and comparing multiple systems for the in vitro culture of CLL cells, we optimized a novel CLL culture system utilizing ULA plates creating spheroids of PBMCs isolated from peripheral blood. Without the addition of soluble factors or stroma, primary CLL cells in the ULA 3D model could be maintained in culture for 6 weeks as opposed to 1 week in the 2D system. Aside from significantly promoting CLL survival, cultures could be expanded approximately 3-4-fold over a course of 6 weeks using the ULA 3D model. 3D cultures showed a more consistent and significantly increased CLL proliferation compared to 2D cultures, independent of IGHV mutation status, increasing the average proliferation index of 2.87 to 3.90 (n=10). Additionally, co-culture with LN-derived stromal cells further increased CLL proliferation, reaching a maximum of 8 generations (n=6) (Figure 1). Lastly, when PBMCs were stimulated with IL-2, IL-15, IL-21 and CpG, spheroids developed proliferation center-like structures after 4 weeks of culture. CONCLUSIONS. We established a lymph node-based 3D in vitro culture system for CLL leading to increased CLL proliferation and survival compared to 2D systems. The set-up allows long-term expansion of CLL cells in vitro, as well as formation of proliferation center-like structures. We are currently optimizing drug resistance studies, expansion of specific CLL subclones and performing competition experiments. References: 1. Hamilton et al., Mimicking the tumour microenvironment: three different co-culture systems induce a similar phenotype but distinct proliferative signals in primary chronic lymphocytic leukaemia cells, 2012. 2. Asslaber et al., Mimicking the microenvironment in chronic lymphocytic leukaemia - where does the journey go?, 2013. 3. Gurski et al., 3D Matrices for Anti-Cancer Drug Testing and Development, 2010. 4. Nunes et al., 3D tumor spheroids as in vitro models to mimic in vivo human solid tumors resistance to therapeutic drugs, 2019. 5. Aljitwai et al., A novel three-dimensional stromal-based model for in vitro chemotherapy sensitivity testing of leukemia cells, 2014. 6. Van Gent et al., In vivo dynamics of stable chronic lymphocytic leukemia inversely correlates with somatic hypermutation levels and suggest no major leukemic turnover in bone marrow, 2008. Disclosures Kater: Genentech: Research Funding; Abbvie: Research Funding; Roche: Research Funding; Janssen: Research Funding; Celgene: Research Funding. Eldering:Celgene: Research Funding; Janssen: Research Funding; Genentech: Research Funding.

scholarly journals CD19 CAR-T Cells Are Highly Effective in Ibrutinib-Refractory Chronic Lymphocytic Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 56-56 ◽  
Author(s):  
Cameron J Turtle ◽  
Laila-Aicha Hanafi ◽  
Daniel Li ◽  
Colette Chaney ◽  
Shelly Heimfeld ◽  
...  
Keyword(s):  
T Cells ◽  
Lymph Node ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Research Funding ◽  
Lymphocytic Leukemia ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Abstract BACKGROUND: Ibrutinib, a Bruton Tyrosine Kinase (BTK) inhibitor causes partial responses (PR) in a majority of patients (pts) with chronic lymphocytic leukemia (CLL). However, complete responses (CR) are rare and high-risk pts who progress on ibrutinib have short survival. Lymphodepletion chemotherapy followed by infusion of CD19-specific chimeric antigen receptor (CAR)-modified T cells has produced encouraging responses in CLL in phase 1 clinical trials, but the majority of pts in those studies had not previously received or failed ibrutinib. METHODS: We treated 18 adults with CLL who had previously received ibrutinib with anti-CD19 CAR-T cells that were manufactured from defined CD4+ and CD8+ T cell subsets obtained by immunomagnetic selection of leukapheresis products, formulated in a final 1:1 ratio of CD8+:CD4+ CAR+ T cells, and infused at 1 of 3 dose levels (2x105, 2x106 or 2x107 CAR-T cells/kg) after lymphodepletion chemotherapy. RESULTS: Eighteen pts (median age 60; range 40-73) with a median of 5 previous therapies (range 3-9), including 3 pts that failed prior allogeneic stem cell transplant were enrolled and treated on the study. All pts were refractory to or had relapsed after receiving a regimen containing fludarabine and rituximab, and all pts had previously received ibrutinib; 11 were ibrutinib-refractory, 3 were ibrutinib-intolerant, and 4 were refractory to venetoclax. Twelve pts had a complex karyotype and 11 pts had 17p deletion. The median percentage of abnormal B cells in marrow was 77% (range 0.4 Ð 96). All pts had extramedullary disease and 2 had CNS disease. Lymphodepletion chemotherapy consisted of cyclophosphamide (Cy) 30-60 mg/kg x 1 and fludarabine (Flu) 25 mg/m2/day x 3 days (n=15); Flu 25 mg/m2/day x 3 days alone (n=2); and Cy 60 mg/kg alone (n=1). CAR-T cells were manufactured for all pts and 16/18 received CD4+ and CD8+ CAR-T cells in the defined 1:1 ratio. Four pts received 2x105, 13 received 2x106 and 1 received 2x107 CAR-T cells/kg. Seventeen pts have completed response and toxicity assessment. Analysis of all pts with B cell malignancies treated with Cy/Flu and CAR-T cells on our trial showed that the highest dose level (2x107 CAR-T cells/kg) was too toxic for an initial CAR-T cell infusion, and identified a maximum tolerated first dose of 2x106 CAR-T cells/kg. Cytokine release syndrome (CRS) was graded according to Lee et al (Blood, 2014). After a single cycle of lymphodepletion chemotherapy and CAR-T cell infusion, 8 pts developed grade (gr) 0-1, 5 had gr 2, 3 had gr 3, and 1 had gr 4 CRS. Four pts developed gr ³3 neurotoxicity (NT). No gr 5 events were observed, no pts were intubated, and only 1 pt required pressors. Three pts received tocilizumab and dexamethasone to treat CRS and/or NT. Four pts received a second cycle of lymphodepletion chemotherapy and CAR-T cells at a 10-fold higher dose than the 1st infusion for persistent disease. CRS and NT (gr3) was observed in 3 of 4 pts after the second cycle of therapy. Restaging was performed 4 weeks after the last CAR-T cell infusion. The ORR was 76% (8 PR and 5 CR). Two of the pts with PR by lymph node size criteria (IWCLL 2008) had negative PET scans after therapy. Among ibrutinib-refractory (n=10) or intolerant pts (n=3), the ORR was 77% (7 PR and 3 CR). In venetoclax refractory pts, 2 of 4 responded (PR). Only 1 of the 3 pts who did not receive Cy/Flu lymphodepletion responded. At day 28, 11 of 13 (85%) pts who received Cy/Flu lymphodepletion and a CAR-T cell infusion at ²2x106 CAR-T cells/kg had complete elimination of marrow disease by flow cytometry; 10/13 (77%) with nodal disease had a PR or CR at restaging, 1 had a mixed response, and 2 had progressive disease (PD). No malignant IGH sequences were detected in marrow of 4/4 pts in CR who underwent IGH deep sequencing. Pts with CR had a higher peak percentage of CD8+ (p=0.006), but not CD4+ CAR-T cells in blood. Robust CAR-T cell expansion was seen in some non-responders, which in conjunction with the lower response rate in nodal sites compared to blood, suggests that factors in the malignant lymph node environment may inhibit CAR-T cell activity. No pt in CR has relapsed or died with a median follow-up of 8.4 months. For the 13 pts that received Cy/Flu lymphodepletion and ≤ 2 x 106 CAR-T cells/kg, OS is 100% and PFS is shown in Fig. 1. CONCLUSION: CD19 CAR-T cells of defined CD4:CD8 ratio are highly active in CLL and can induce high response rates and durable CRs in poor prognosis pts who have previously failed ibrutinib. Disclosures Turtle: Juno Therapeutics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria. Li:Juno Therapeutics: Employment, Equity Ownership. Riddell:Adaptive Biotechnologies: Consultancy, Honoraria; Cell Medica: Consultancy, Honoraria; Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding. Maloney:Juno Therapeutics: Research Funding; Genentech/Roche: Honoraria.

Combined Inhibition of mTOR and DNA-PK Blocks Survival, Adhesion, Proliferation and Chemoresistance in Primary Chronic Lymphocytic Leukemia (CLL) Cells

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1981-1981 ◽  
Author(s):  
Rachel Thijssen ◽  
Gregor van Bochove ◽  
Ingrid AM Derks ◽  
Johanna ter Burg ◽  
Martin FM de Rooij ◽  
...  
Keyword(s):  
Clinical Trials ◽  
T Cells ◽  
Dna Repair ◽  
Lymph Node ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Research Funding ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Lymphocytic Leukemia

Abstract CLL progression and chemoresistance can result from signals from the lymph node (LN) microenvironment and from acquired aberrations in the DNA damage repair (DDR) pathway. Clinical targeting of kinases upstream in the B cell receptor (BCR) activation pathway, such as Btk or PI3Kδ results in egress of cells from the LN microenvironment [1,2]. Such prolonged lymphocytosis during kinase-inhibitor treatment appears to pose no clinical disadvantage [3]. However, it enhances the chance of accumulating resistance-inducing mutations, and therefore drugs that combine LN egress with direct cytoxicity could provide an improved therapeutic strategy for CLL. The mTOR complex, consisting of mTOR1 and 2, is the main downstream kinase of the PI3K/Akt pathway and contributes to proliferation and survival. DNA-PK is a kinase required for non-homologous end joining (NHEJ) of the DNA repair pathway. Inhibitors of crucial components of the DDR pathway might be active in CLL, especially in patients harboring mutations in DNA repair molecules such as Ataxia telangiectasia mutated (ATM). In this study the potency of a novel dual mTOR1,2 and DNA-PK inhibitor (CC-115) was studied in primary CLL samples of different prognostic subgroups with respect to induction of cytotoxicity, and inhibition of adhesion, CD40-mediated chemoresistance and proliferation. In vitro, CC-115 inhibited mTOR1 and 2 and also affected the DDR reflected by inhibition of irradiation-induced γH2AX, not only in ATM-mutated but also in ATM-wild type CLL cells. CC-115 showed induction of caspase-dependent cell killing (IC50=0.625µM) which was more robust than selective kinase inhibitors (table 1), irrespective of p53 or ATM status. This cytotoxic effect was not observed in the T cells from CLL patients. BCR-mediated adhesion to fibronectin [4] was inhibited by CC-115 to a similar extent as PI3Kδ inhibitor (idelalisib) (table 1). CD40-mediated chemoresistance [5] could be reverted completely by CC-115 while more specific inhibitors had only modest effects. CLL proliferation induced by CD40L+IL-21 treatment [6] was completely blocked by both CC-115 and a dual mTOR1,2 inhibitor but not by inhibitor of the more upstream kinase PI3Kδ (table 1). In conclusion, these data show that CC-115 induces direct cytotoxicity and inhibits several clinically relevant biological features of CLL, and provide a rationale for clinical trials with CC-115 in CLL patients. [1] Hoellenriegel J, Meadows SA, Sivina M et al. The phospoinositide 3’-kinase delta inhibitor, CAL-101, inhibits B-cell receptor signaling and chemokine networks in chronic lymphocytic leukemia. Blood 2011;(118):3603-3612 [2] Burger JA. Bruton’s Tyrosine Kinase (BTK) Inhibitors in Clinical Trials. Curr Hematol Malig Rep (2014) 9:44–49 [3] Herman SE, et al. Ibrutinib-induced lymphocytosis in patients with chronic lymphocytic leukemia: correlative analyses from a phase II study. Leukemia. 2014 Apr 4. doi: 10.1038/leu.2014.122. [Epub ahead of print] [4] de Rooij MF, Kuil A, Geest CR et al. The clinically active BTK inhibitor PCI-32765 targets B-cell receptor- and chemokine-controlled adhesion and migration in chronic lymphocytic leukemia. Blood 2012;(119):2590-2594. [5] Differential Noxa/Mcl-1 balance in peripheral versus lymph node chronic lymphocitic leukemia cells correlates with survival capacity. Blood 2007;(109):1660-1668. [6] Pascutti MF, Jak M, Tromp JM et al. IL-21 and CD40L signals from autologous T cells can induce antigen-independent proliferation of CLL cells. Blood 2013;(122):3010-3019.Smit LA, Hallaert DY, Spijker R et al. Table 1. The effect of the mTOR1,2 + DNA-PK inhibitor (CC-115), mTOR1,2 inhibitor (CC-214), DNA-PK inhibitor (NU7441) and PI3Kδ inhibitor (idelalisib) on CLL cells in functional assays. CC-115 CC-214 NU7441 Idelalisib (CAL-101) Target mTOR1,2 DNA-PK mTOR1,2 DNA-PK PI3Kδ Cytotoxicity (IC50) 0.625 µ M >10µM >10µM >10µM Inhibition of adhesion 40%** 0% 22% 48%** Activation Inhibition of CD40-mediated resistance to fludarabine (6.25 µ M) 92%** 42%* n.d. 21% Inhibition of CD40L+IL21 induced proliferation 98%** 98%* 28% 51%** n.d. = not done The one sample T test was used to determine the significance of differences between means of treated samples and normalized values of untreated samples (100%). * p <0,05;** p<0,01 Disclosures Kersten: Celgene: Research Funding. Kater:Celgene: Research Funding.

scholarly journals Ibrutinib Treatment in CLL Interrupts CD40 Signaling Capacity and Sensitizes CLL Cells to Venetoclax

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1545-1545
Author(s):  
Karoline Kielbassa ◽  
Marco Haselager ◽  
Danique Bax ◽  
Julie Dubois ◽  
Mark-David Levin ◽  
...  
Keyword(s):  
Lymph Node ◽  
Chronic Lymphocytic Leukemia ◽  
Research Funding ◽  
Kinase Inhibitor ◽  
Lymphocytic Leukemia ◽  
Cell Surface Expression ◽  
P Value ◽  
Cd40 Expression

Abstract Background: For proliferation and survival, chronic lymphocytic leukemia (CLL) cells depend on interactions with cells and soluble factors present in the tumor microenvironment (TME). These interactions also increase expression of B-cell leukemia/lymphoma-2 (Bcl-2) proteins, including Bcl-XL, Mcl-1 and Bfl-1, thereby reducing drug sensitivity. In the VISION HOVON141 clinical trial, patients with relapsed or refractory CLL are treated with 2 cycles of Bruton tyrosine kinase inhibitor ibrutinib (IBR) lead-in followed by 13 cycles of IBR + Bcl-2 inhibitor venetoclax (VEN) combination before randomization. The combination of IBR + VEN may have synergistic anti-tumor effects, since IBR forces CLL cells from lymph node (LN) to the blood (PB) where they become fully dependent on Bcl-2, and succumb to VEN. To support a mechanistic basis for this premise, we investigated changes in expression of Bcl-2 proteins, effects of TME-mimicking signals, and venetoclax sensitivity before/after 2 months IBR treatment. Results: At baseline, lymph node emigrant cells (CXCR4dim/CD5high) have higher Bfl-1 expression, in addition to earlier reported Bcl-XL and Mcl-1 expression than cells immigrating back to the lymph node (CXCR4high/CD5dim)(Haselager et al., 2020). After 2 months of IBR treatment a clear reduction in all four pro-survival proteins was observed (N=17 p&lt;0.001). Despite these changes, VEN sensitivity was not different in unstimulated PB CLL cells obtained at baseline versus at 2 months of IBR treatment (N=8; IC50=0.001µM). In contrast, CD40 stimulated CLL cells obtained at baseline are fully resistant to VEN (IC50&gt;10µM), but unexectedly retained partial sensitivity to venetoclax after IBR treatment (IC50=0.05 µM, p-value &lt;0.0001; Figure 1A). This suggested reduced CD40 signalling capacity and was accompanied by reduced ability to upregulate Bcl-XL, Mcl-1, and Bfl-1 expression. Indeed, cell surface expression, as well as level of CD40 activation as measured by CD95 induction, was clearly reduced after 2 months IBR. Importantly, these effects occurred in vivo, as IBR did not directly affect CD40 signaling in vitro. These data imply that under IBR treatment, when cells cannot (re-)enter LN sites, a factor is lacking that maintains or induces CD40 expression. In search of stimuli that can augment CD40 signaling capacity, it was found that BCR stimulation had no effect on CD40 expression. In contrast, TLR9 stimulation via CpG led to increased CD40 expression in CLL cells (N=7, p-value &lt;0.0001)(Figure 1B). These findings align well with recent data which indicate a role for TLR9 signalling in vivo by unmethylated mitochondrial DNA in CLL (Kennedy et al., 2021). Taken together, these data provide a mechanistic explanation, by which a triad of signaling pathways not only involving BCR but also CD40 and TLR9 is interrupted by IBR (Figure 1C). Discussion/conclusion: IBR treatment broadly affects Bcl-2 family protein expression and CD40 signaling in vivo. The combined data indicate a novel aspect of IBR efficacy, namely its capacity to interrupt TLR9-induced CD40 upregulation, which normally primes CLL cells in the LN environment for drug resistance. This also suggests that drugs that inhibit TLR9 signaling may synergize with IBR. References Haselager, M. V., et al (2020). Changes in Bcl-2 members after ibrutinib or venetoclax uncover functional hierarchy in determining resistance to venetoclax in CLL. Blood, 136(25), 2918 Kennedy, E., et al (2021). TLR9 expression in chronic lymphocytic leukemia identifies a promigratory subpopulation and novel therapeutic target. Blood, 137(22), 3064 Figure 1 Figure 1. Disclosures Levin: Roche, Janssen, Abbvie: Other: Travel Expenses, Ad-Board. Westerweel: Novartis: Research Funding; Incyte: Consultancy; BMS / Celgene: Consultancy; Pfizer: Consultancy. Niemann: CSL Behring, Genmab, Takeda, Octapharma: Consultancy; Novo Nordisk Foundation: Research Funding; Abbvie, AstraZeneca, Janssen: Consultancy, Research Funding.

scholarly journals Mechanisms of Adaptation to Ibrutinib in High Risk Chronic Lymphocytic Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 585-585 ◽  
Author(s):  
Valeria Spina ◽  
Gabriela Forestieri ◽  
Antonella Zucchetto ◽  
Alessio Bruscaggin ◽  
Tamara Bittolo ◽  
...  
Keyword(s):  
High Risk ◽  
Chronic Lymphocytic Leukemia ◽  
Nuclear Localization ◽  
Peripheral Blood ◽  
Research Funding ◽  
Clonal Evolution ◽  
Lymphocytic Leukemia ◽  
Adaptation Process ◽  
Over Time ◽  
Stimulation Of

Abstract Introduction. Ibrutinib inhibits the BTK molecule downstream the B-cell receptor (BCR). Though highly active in high risk chronic lymphocytic leukemia (CLL), the most typical response achievable in patients is a minimal residual disease (MRD) positive partial remission (PR) which is maintained until the development of genetically driven resistance caused by the acquisition of mutations in the BTK or PLCG2 genes. The study aims at characterizing the adaptation process allowing residual CLL cells to persist despite BTK inhibition. Methods. The IOSI-EMA-001 study (NCT02827617) is an observational study consisting in the prospective and longitudinal collection of peripheral blood samples and clinical data from high risk CLL patients treated with ibrutinib. Peripheral blood CLL cells longitudinally drawn from patients before treatment start and at fixed timepoints under ibrutinib were monitored by: i) next generation flow cytometry approaches for changes in proliferation rate, surfaceome, and pathway activation; and ii) CAPP-seq targeted deep next generation (sensitivity ~10-3) for clonal evolution. Results. The study cohort comprised 31 high risk CLL patients, including 15 treatment naïve, 16 relapsed, 80% IGHV unmutated, 42% 17p deleted and 55% TP53 mutated. Median duration of ibrutinib treatment was 45 weeks (24-72 weeks). All patients obtained a MRD positive PR that was maintained in all but one who progressed with a PLCG2 mutation (VAF 3%). Compared to baseline, under ibrutinib therapy CLL cells slowed down their proliferation, as suggested by the decreased expression of Ki-67, the reduction of the proliferating fraction (CXCR4dimCD5bright), and the increase of the resting fraction (CXCR4brightCD5dim). Compared to baseline, under ibrutinib therapy CLL cells also upregulated BCR and adhesion/homing proteins, and decreased the expression of BCR inhibitor proteins. Upon stimulation of the BCR with anti-IgM, the downstream path through pBTK and pPLCG2 was inhibited by ibrutinib, while conversely the downstream path through pAKT and pERK was still inducible throughout all the assessed timepoints. The proportion of CLL cells harboring nuclear localization of NF-kB progressively increased over time under ibrutinib. NF-kB nuclear localization was inducible throughout all the assessed timepoints by CD40L stimulation of the non-canonical NF-kB pathway, but not by anti-IgM stimulation of the BCR/canonical NF-kB pathway. Overall, 880 individual mutations were longitudinally discovered and monitored across a total of 121 sequential timepoints collected during ibrutinib treatment. Clonal evolution was observed in (67.7%) cases, a proportion rate previously documented in CLL treated with chemoimmunotherapy. Clonal evolution appeared to be heterogeneous involving different genes without a stereotypic targeting. Consistently, none of the main driver gene mutations was homogeneously selected or suppressed by ibrutinib suggesting that the biological adaptation of CLL cells under ibrutinib is not genetically driven. Clonal evolution propensity was not associated with any of the biomarkers of the disease, and it did not decrease over time under ibrutinib. Conclusions. Taken together these results suggest that residual CLL cells persisting under ibrutinib therapy adapt their phenotype by upregulating adhesion molecules, chemokine receptors and BCR molecules, and by maintaining a competence of BCR signaling through the PI3K/AKT/ERK pathway. The progressive selection of CLL cells having NF-kB in the nucleus, likely due to the BTK independent non-canonical NF-kB pathway, might explain their survival despite ibrutinib therapy. Finally, clonal evolution is not suppressed by ibrutinib chemotherapy, and despite does not seem to be directly involved in such adaptation process, may ultimately favor the acquisition of BTK and PLCG2 ibrutinib resistance mutations. Disclosures Zucca: Celltrion: Consultancy; AstraZeneca: Consultancy. Ghia:Sunesis: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; AbbVie, Inc: Honoraria, Research Funding; Acerta: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; BeiGene: Honoraria, Research Funding. Montillo:Janssen: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Speakers Bureau; AbbVie: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Research Funding. Tedeschi:Janssen: Consultancy, Speakers Bureau; Gilead: Consultancy; AbbVie: Consultancy. Gaidano:AbbVie: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Morphosys: Honoraria; Roche: Consultancy, Honoraria.

scholarly journals Lenalidomide and Rituximab Maintenance Therapy after Front-Line Induction Chemoimmunotherapy in Chronic Lymphocytic Leukemia and Small Lymphocytic Lymphoma

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5470-5470
Author(s):  
Julie E Chang ◽  
Vaishalee P. Kenkre ◽  
Christopher D. Fletcher ◽  
Aric C. Hall ◽  
Natalie Scott Callander ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Maintenance Therapy ◽  
Research Funding ◽  
Lymphocytic Leukemia ◽  
Second Malignancies ◽  
Front Line ◽  
First Line ◽  
11Q Deletion ◽  
Line Chemotherapy

Introduction: Chronic lymphocytic leukemia (CLL) is incurable with standard therapy. With first-line chemotherapy, some patients (pts) may achieve durable remissions of many months/years. Lenalidomide (LEN) has improved progression-free survival (PFS) when given as maintenance (MNT) therapy after front-line chemotherapy (CALGB10404, CLLM1). The combination of LEN + rituximab (LR) has activity in relapsed CLL, hypothesizing benefit as MNT therapy after first-line chemotherapy. Methods: Adult pts ≥18 years with previously untreated CLL received induction bendamustine (B) 90 mg/m2 IV days 1 & 2 and rituximab (R) IV day 1 (375 mg/m2 cycle 1, then 500 mg/m2 cycles 2-6) for 6 treatment cycles (as few as 4 cycles allowed). MNT therapy with LR was initiated within 12 weeks after cycle 6, day 1 of BR. Criteria to start LR MNT included: neutrophils ≥1000/microliter (uL), platelets ≥75 K/uL, and creatinine clearance ≥40 mL/min. LEN was administered in 28-day cycles for 24 cycles, initially 5-10 mg daily continuous dosing, later modified to 5-10 mg on days 1-21 of each 28-day cycle in 6/2018 due to neutropenia and second malignancy risk. LEN was reduced to 5 mg every other day for toxicities at 5 mg/day. R 375 mg/m2 IV was given every odd cycle (total of 12 doses). Patients discontinuing LEN for any reason were allowed to continue R MNT per protocol. The primary endpoint is PFS with LR MNT therapy, calculated from the first day of MNT therapy until progressive disease (PD), death, or start of a new therapy. Secondary endpoints are response rate and overall survival. Results: Thirty-four pts have enrolled beginning 11/2013, with follow-up through 6/2019. Median age is 64 years, with 8 pts ≥70 years; 8 women and 26 men. CLL FISH panel is available on all pts: 14 with 13q (as sole abnormality), 9 with 11q deletion, 6 with trisomy 12, 4 with normal FISH panel and 1 with 17p deletion. Heavy chain mutation analysis is available on 11 pts: 8 unmutated, 2 mutated, 1 indeterminate. Thirty-one pts completed 4 (n=2) or 6 cycles of induction BR; 3 pts are receiving induction BR. Twenty-four pts have received MNT LR; 7 did not receive LR for reasons of PD during induction (n=2), infection (n=1), pt preference (n=2), renal insufficiency (n=1), and new carcinoma (n=1). MNT LR was completed in 7 pts; 9 pts are still receiving LR. Fourteen subjects have discontinued protocol therapy, 3 during induction due to PD (n=2) and infection (n=1), and 8 during MNT. Toxicities that led to discontinuation of LR were recurrent infections in 7 pts, including 2 events of PJP pneumonia; 4 pts had recurrent neutropenia with infections; 1 pt had neutropenia without infections. Response is assessable in 31 patients using the International Working Group Consensus Criteria. Best responses to treatment were: partial response 65% (22/34), complete response (CR)/unconfirmed CR 24% (8/34). The median number of MNT cycles received is 16. The dose intensity of LEN across total cycles received (n=278): 5 mg every other day (52.5%), 5 mg/day (43.9%), and 10 mg/day (3.6%). The most common reason for dose reduction or dose holding was neutropenia. Most common Gr 3/4 toxicities (reported as events Gr3/Gr4) during MNT therapy were: neutropenia (20/20), leukopenia (19/4), febrile neutropenia (3/1), and infections (11/-). The majority of Gr3 infections were pneumonia/respiratory (n=5). One event of disseminated herpes zoster occurred. Second malignancies during MNT included: basal cell CA (n=1), squamous cell carcinoma (n=5), and colon cancer (n=1). No unexpected second malignancies were observed in pts receiving LR. Two-year PFS (defined from day 1 of MNT therapy) is 90% (95% confidence interval [CI] 0.78-1), and the median follow-up for 24 patient who started maintenance therapy is 1.79 years (95% CI 1.53-2.7). There have been no deaths. Conclusion: The combination of LR is effective in sustaining remissions after a BR induction in previously untreated CLL, but with frequent neutropenia and infections even at low doses of LEN. Most patients discontinuing MNT did so due to neutropenia and/or infections. A shorter planned interval of MNT LR (i.e., 6-12 months) may confer similar benefit to extended dosing that is more tolerable. Pts at high risk for short remissions after front-line chemotherapy (e.g., unmutated heavy chain status, 11q deletion and/or failure to achieve minimal residual disease after induction) may be the populations for which LR MNT therapy is most appropriate. Disclosures Chang: Genentech: Research Funding; Adaptive Biotechnologies: Research Funding; Celgene: Research Funding. OffLabel Disclosure: Lenalidomide administered as maintenance therapy for first treatment of CLL/SLL.

scholarly journals Impact of Idelalisib Treatment Interruption with or without Dose Reduction on Outcomes in Relapsed / Refractory Indolent Non-Hodgkin's Lymphoma and Chronic Lymphocytic Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5468-5468
Author(s):  
Shuo Ma ◽  
Rebecca J Chan ◽  
Lin Gu ◽  
Guan Xing ◽  
Nishan Rajakumaraswamy ◽  
...  
Keyword(s):  
Overall Survival ◽  
Chronic Lymphocytic Leukemia ◽  
Board Of Directors ◽  
Dose Reduction ◽  
Clinical Outcomes ◽  
Research Funding ◽  
Treatment Interruption ◽  
Lymphocytic Leukemia ◽  
Hodgkin's Lymphoma ◽  
Advisory Committees

Introduction: Idelalisib (IDELA) is the first-in-class PI3Kδ inhibitor and is approved as a monotherapy for relapsed or refractory (R/R) follicular lymphoma and in combination with rituximab for R/R chronic lymphocytic leukemia (CLL). We previously evaluated IDELA treatment interruption as a mechanism to mitigate treatment-emergent adverse events (TEAEs) and found that limited interruption with clinically appropriate re-challenging resulted in superior clinical outcomes. These findings did not comprehensively address the potential confound of interruptions inherently being associated with longer duration of therapy (DoT). Furthermore, the compound effect of IDELA dose reduction together with treatment interruption on IDELA efficacy was not assessed. Objectives: 1) To evaluate whether the benefit of IDELA interruption is retained in patients on therapy >180 days, a duration previously found to be associated with longer overall survival among patients who discontinued IDELA due to an AE; and 2) To compare clinical outcomes of patients who reduced IDELA dosing in addition to interrupting IDELA with those of patients who interrupted IDELA without additional dose reduction. Methods: Using data from Gilead-sponsored trials of patients with R/R indolent non-Hodgkin's lymphoma (iNHL) treated with IDELA monotherapy (N=125, Gopal et al., N. Engl. J. Med., 2014) or with R/R CLL treated with IDELA + anti-CD20 (N=110, Furman et al., N. Engl. J. Med., 2014; and N=173, Jones et al., Lancet Haematol., 2017), DoT, progression-free survival (PFS), and overall survival (OS) were compared between patients on IDELA therapy >180 days with vs. without interruption and between patients who experienced Interruption and Dose Reduction (IDR) vs. patients who experienced Interruption but NoDose Reduction (INoDR) at any point during IDELA treatment. Interruption was defined as missing at least one IDELA treatment day due to an AE and dose reduction could have occurred before or after the first interruption. PFS and OS were estimated using the Kaplan-Meier method and were compared using a log-rank test. Results: Sixty-nine of 125 patients with R/R iNHL (55.2%) and 222 of 283 patients with R/R CLL (78.4%) remained on IDELA therapy >180 days with 29 (42.0%) and 103 (46.4%) of them, respectively, experiencing interruption on or after day 180 (Table 1). The proportions of patients with interruption before day 180 were similar within each of these populations. Among patients on therapy >180 days, those with treatment interruption on or after 180 days had a longer median (m) DOT than patients without interruption (Table 1). Both PFS and OS were longer in CLL patients who interrupted compared to those who did not interrupt (mPFS=28.9 mos. vs. 17.3 mos. and mOS=not reached [NR] vs. 40.4 mos. for with interruption vs. without interruption, respectively, Table 1 and Figure 1). In patients with iNHL, no difference was observed in PFS or OS between patients who interrupted vs. those who did not (Table 1). Of patients who experienced at least one AE-induced interruption at any point during IDELA therapy (n=63 iNHL and n=157 CLL), 47 iNHL patients (74.6%) and 84 CLL patients (53.5%) also had dose reduction. Two iNHL patients (1.6%) and 5 CLL patients (1.8%) had IDELA dose reduction but no interruption. Both iNHL and CLL patients with IDR experienced a similar PFS compared to patients with INoDR (mPFS=16.5 mos. vs. 14.2 mos. for iNHL and 21.8 mos. vs. 22.1 mos. for CLL with IDR vs. INoDR, respectively, Table 2). However, OS was longer in both iNHL and CLL patients with IDR compared to INoDR (mOS=61.2 mos. vs. 35.3 mos. for iNHL and NR vs. 42.4 mos. for CLL, respectively, Table 2; CLL patients shown in Figure 2). Discussion: IDELA treatment interruption is not associated with rapid clinical deterioration, as observed with some B-cell receptor signaling pathway inhibitors. No clear relationship between IDELA DoT and frequency of interruption was observed. When normalized for DoT >180 days, IDELA treatment interruption retained its clinical benefit in the CLL population. When utilized together with IDELA interruption, dose reduction did not lead to inferior clinical outcomes but instead extended OS in both iNHL and CLL populations. Adherence to treatment interruption and dose reduction guidance as outlined in the IDELA USPI may optimize IDELA tolerability and efficacy for patients with iNHL and CLL. Disclosures Ma: Janssen: Consultancy, Speakers Bureau; Pharmacyclics: Consultancy, Research Funding, Speakers Bureau; Gilead: Research Funding; Abbvie: Research Funding; Juno: Research Funding; Incyte: Research Funding; Xeme: Research Funding; Beigene: Research Funding; Novartis: Research Funding; Astra Zeneca: Consultancy, Research Funding, Speakers Bureau; Kite: Consultancy; Acerta: Research Funding; Bioverativ: Consultancy; Genentech: Consultancy. Chan:Gilead Sciences, Inc.: Employment, Equity Ownership. Gu:Gilead Sciences, Inc.: Employment. Xing:Gilead Sciences, Inc.: Employment. Rajakumaraswamy:Gilead Sciences, Inc.: Employment. Ruzicka:Gilead Sciences, Inc.: Employment. Wagner-Johnston:Gilead: Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Jannsen: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees.

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