scholarly journals The Tigit/CD226/CD155 Immunomodulatory Axis Is Deregulated in CLL and Contributes to B-Cell Anergy

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3718-3718
Author(s):  
Francesca Arruga ◽  
Andrea Iannello ◽  
Nikolaos Ioannou ◽  
Alberto Maria Todesco ◽  
Marta Coscia ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Cell Receptor ◽  
Tcr Signaling ◽  
Advisory Committees ◽  
Cell Responses ◽  
Blocking Antibodies

Abstract BACKGROUND. T cell immunoreceptor with Ig and ITIM domains (TIGIT) is an inhibitory receptor expressed on T, NK and NKT cells, sharing structural and mechanistic similarities with PD-1 and CTLA-4. TIGIT competes with CD226, its partner receptor, for the binding to CD155 ligand: signaling triggered upon CD155 binding to CD226 potentiates T cell receptor (TCR) signaling and CD8 + T cell cytotoxicity against tumor cells (positive signaling). On the contrary, concomitant TIGIT expression on the cell surface prevents CD226 activation either by sequestering CD155 or by impeding CD226 homodimerization and phosphorylation (negative signaling). Recently, TIGIT was shown to be expressed on the surface of normal memory B cells, where it could directly act to suppress T cell responses. No data are available on TIGIT or CD226 expression by chronic lymphocytic leukemia (CLL) cells. AIM AND METHODS. Our aim was to investigate expression of the TIGIT and CD226 receptors and of the CD155 ligand in a cohort of clinically and molecularly annotated CLL patient samples. To this end, we designed a multiparametric panel of antibodies for flow cytometry and examined expression of the TIGIT/CD226/CD155 axis in peripheral blood mononuclear cells (PBMC) from our patient cohort. To investigate the impact of TIGIT/CD226 engagement on B cell responses, purified leukemic B cells were activated either through the B cell receptor (BCR) using an αIgM polyclonal antibody or with CpG oligonucleotide and interleukin 15 (IL-15) to induce proliferation. In selected experiments, we added recombinant human (Rh) TIGIT-Fc or CD155-Fc chimeras and αTIGIT or αCD226 blocking antibodies to interfere with this axis. RESULTS. Surface expression of TIGIT, CD226 and CD155 was evaluated in a cohort of 115 CLL samples and compared to age- and sex-matched healthy subjects. Both TIGIT and CD226 were upregulated on leukemic B cells compared to normal B lymphocytes, while CD155 was expressed at lower levels. A similar trend was observed on CD4 + and CD8 + T lymphocytes. High-risk CLLs (unmutated IgV genes, unfavorable cytogenetics and advanced stage) were predominantly TIGIT low and CD226 high, indicating an unbalance towards "positive signaling". Results were confirmed by confocal microscopy analyses on lymph node (LN) biopsies, which showed i) an overall higher TIGIT expression in CLL compared to reactive LNs and ii) among CLL LNs a stronger TIGIT positivity in mutated vs unmutated cases, confirming flow cytometry data. In line with these findings, Richter's syndrome samples and patient-derived xenografts models showed the lowest TIGIT and the highest CD226 levels. We next examined TIGIT axis expression during the follow up of CLL cases who underwent treatment with BTK inhibitor (BTKi). While CD226 levels remained unmodified upon treatment, a sharp decrease in surface TIGIT was detected soon after BTKi initiation. Since TIGIT acts by decreasing TCR signaling to shut down T cell responses, we hypothesized similar functions in B cells. By crosslinking the BCR with an αIgM antibody in a selected cohort of IGHV UM CLL cells, we found that BTK phosphorylation was induced to a lesser extent in TIGIT high compared to TIGIT low samples, suggesting that TIGIT is a marker of CLL cell anergy. Accordingly, interruption of receptors/ligand interactions with RhTIGIT-Fc chimera or with αTIGIT or αCD226 blocking antibodies, modulated BCR signaling capacity. Specifically, in TIGIT high samples, preventing receptor engagement by CD155 increased αIgM-induced BTK phosphorylation; in contrast, in TIGIT low samples, blocking CD155 interaction affected mostly CD226 signaling, thereby depotentiating BCR activation. Similar results were obtained when stimulating CLL cells with CpG/IL-15. Interestingly, we observed a significant upregulation of surface CD226 in CLL cells cultured for 6 days in the presence of CpG/IL-15. CONCLUSIONS. These results show for the first-time expression of TIGIT by CLL cells. Furthermore, they indicate that TIGIT is a marker of CLL cells anergy, whereas activated CLL cells express high levels of CD226. Inhibition of TIGIT binding to CD155 partially restores B cell signaling and activation. Future studies are needed to gain insights on the mechanisms behind its deregulation and to obtain a complete functional characterization of the axis. Disclosures Coscia: AbbVie: Honoraria, Other; Janssen: Honoraria, Other, Research Funding; AstraZeneca: Honoraria; Gilead: Honoraria. Gaidano: Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astrazeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Beigene: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Allan: Genentech: Consultancy, Research Funding; Epizyme: Consultancy; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria; BeiGene: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Celegene: Research Funding; AstraZeneca Pharmaceuticals LP, Genentech, a member of the Roche Group, Janssen Biotech Inc, TG Therapeutics Inc.: Research Funding; AbbVie Inc, AstraZeneca Pharmaceuticals LP, BeiGene, Janssen Biotech Inc, Pharmacyclics LLC: Consultancy; AbbVie Inc, Ascentage Pharma, Epizyme, Genentech, a member of the Roche Group, Janssen Biotech Inc, Pharmacyclics LLC: Other: Advisory Committee; TG Therapeutics: Research Funding. Furman: Oncotracker: Consultancy; Verastem: Consultancy; Abbvie: Consultancy, Honoraria, Other: Expert testimony; Sunesis: Consultancy; Incyte: Consultancy; Beigene: Consultancy; Acerta/AstraZeneca: Consultancy; Loxo Oncology: Consultancy; Genentech: Consultancy; Morphosys: Consultancy; Pharmacyclics: Consultancy; Sanofi: Consultancy; TG Therapeutics: Consultancy; X4 Pharmaceuticals: Consultancy; Janssen: Consultancy, Honoraria; AstraZeneca: Honoraria. Deaglio: Heidelberg Pharma: Research Funding; Astra Zeneca: Research Funding.

Regulatory B Cell Defects In Patients with Immune Thrombocytopenia (ITP)

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 379-379 ◽  
Author(s):  
Xiaojuan Li ◽  
Hui Zhong ◽  
Weili Bao ◽  
Nayla Boulad ◽  
James B. Bussel ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
T Cell Responses ◽  
Healthy Controls ◽  
Advisory Committees ◽  
Cell Responses ◽  
Regulatory Capacity

Abstract Abstract 379 B lymphocytes participate in immune responses through production of antibodies, antigen presentation to T cells, and cytokine secretion. In ITP, B cells that produce platelet-specific autoantibodies play a major role in the pathogenesis of disease. Recent data from mouse models of autoimmune and inflammatory diseases suggest that B cells have regulatory functions mediated by the production of regulatory cytokines such as IL-10 and/or through inhibitory interactions with effector T cells. In humans, CD19+CD24hiCD38hi B cells, originally identified as immature transitional B cells, were recently shown to possess regulatory capacity mediated in part by IL-10. Given that ITP pathogenesis is in part related to defective T helper functions and since Bregs are important for controlling CD4+ T cell responses, we initiated studies to characterize the CD19+CD24hiCD38hi B cell compartment in ITP patients. Phenotypic analysis in patients with ITP showed statistically significant increases in the frequency of CD19+CD24hiCD38hi B cells (13.2± 1.5% versus 7.7±0.6%, p=0.0015) as well as in the percentage of CD19+CD24hiCD38int mature B cells (72.0± 1.7% versus 62.3±1.6%, p=0.0003). In contrast there was a pronounced decrease in CD19+CD24hiCD38− memory B cells (9.3± 2% versus 26.2±2%, p<0.0001 as confirmed by expression of CD27 memory marker) in patients (n=23) compared to healthy controls (n=23). The suppressive capacity of human CD19+CD24hiCD38hi Bregs involves CD80. We found a statistically significant decrease in the overall frequency of CD80 expressing CD19+ B cells in ITP patients compared to healthy controls (12.40± 1.3% versus 21.8±2.1%, p=0.002), indicating that despite the increase in the Breg frequency, their regulatory capacity may be impaired. To determine the functional activity of the Bregs, PBMCs from 4 patients with ITP were depleted of CD19+CD24hiCD38hi B cells by cell sorting and levels of cytokine production in the CD4+ T cell population following stimulation with plate-bound anti-CD3 for 72h was evaluated. As has been reported previously, we observed a >30% increase in the frequency of CD4+IFN-g+ in CD19+CD24hiCD38hi B cell-depleted compared with non-depleted PBMCs from healthy controls. However, depletion of CD19+CD24hiCD38hi B cells from PBMCs of ITP patients did not alter CD4+IFN-g+ production in 3 /4 patients, indicating a possible defect in the suppressive activity of Bregs in those 3 patients. IL-10 secretion following CD40 engagement in human Bregs is pivotal in mediating their suppressive activity. Given that platelets express CD40L, we tested the ability of Bregs to respond to platelets. We found two-fold lower IL-10 production in CD19+CD24hiCD38hi Bregs (1.9±2.1%, versus 5.0± 1.0%, p<0.05), but not in CD19+CD24hiCD38− B cells (p=0.9) from patients (n=3, different from above) compared to controls (n=5) when PBMCs were stimulated with acid-treated platelets (to remove HLA molecules) from normal controls, indicating a defect in IL-10 production in the Breg population in patients with ITP. Altogether, our in vitro studies of circulating Bregs suggest that these cells may be functionally compromised in some patients with ITP patients as indicated by reduced IL-10 production and indirectly by Breg depletion studies showing inability to dampen effector T cell responses. Given the important role of Bregs in controlling CD4+T responses, the data implicates defective Bregs as an additional mechanism to explain increased T cell responses in patients with ITP. The impaired Breg activity may also explain the variability in response to treatment with anti-CD20 in patients with ITP. It may be that B cell depletion therapy in patients who have defective Breg activity will result in the removal of primarily pathogenic B cells and therefore these patients will have a good response to rituximab treatment. However, in patients with intact Bregs, the same treatment will deplete both pathogenic and regulatory B cells, causing a less effective response. Ongoing studies to test patients' platelets as well as CD40-specific Breg responsiveness are currently underway to further explore the role of Bregs in the pathogenesis of ITP. Disclosures: Bussel: Portola: Consultancy; Amgen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; GlaxoSmithKline: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; Ligand: Membership on an entity's Board of Directors or advisory committees, Research Funding; Shionogi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai, Inc.: Membership on an entity's Board of Directors or advisory committees; Cangene: Research Funding; Genzyme: Research Funding.

scholarly journals First-in-Human, Phase 1/2 Trial to Assess the Safety and Clinical Activity of Subcutaneous GEN3013 (DuoBody®-CD3×CD20) in B-Cell Non-Hodgkin Lymphomas

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 758-758 ◽  
Author(s):  
Pieternella Lugtenburg ◽  
Rogier Mous ◽  
Michael Roost Clausen ◽  
Martine E.D. Chamuleau ◽  
Peter Johnson ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Board Of Directors ◽  
Dose Escalation ◽  
Research Funding ◽  
Clinical Activity ◽  
Employment Equity ◽  
Advisory Committees ◽  
Equity Ownership

Introduction: CD20-specific monoclonal antibodies (mAbs) have demonstrated efficacy in the treatment of B-cell non-Hodgkin lymphomas (B-NHL); however, a significant proportion of patients (pts) present with refractory disease or will experience relapse. GEN3013 (DuoBody®-CD3×CD20) is the first subcutaneously administered IgG1 bispecific antibody (bsAb) that targets the T-cell surface antigen CD3 and the B-cell surface antigen CD20, triggering T-cell-mediated killing of B cells. In vitro, GEN3013 efficiently activates and induces cytotoxic activity of CD4+ and CD8+ T cells in the presence of B cells (Hiemstra et al. Blood 2018), and results in long-lasting depletion of B cells in cynomolgus monkeys. Subcutaneous (SC) GEN3013 in cynomolgus monkeys resulted in lower plasma cytokine levels, and similar bioavailability and B-cell depletion, compared with intravenous administration. GEN3013 has higher potency in vitro than most other CD3×CD20 bsAbs in clinical development (Hiemstra et al. HemaSphere 2019). SC GEN3013 in pts with B-NHL is being evaluated in a first-in-human, Phase 1/2 trial (NCT03625037), which comprises a dose-escalation part and a dose-expansion part. Here we report preliminary dose-escalation data. Methods: Pts with CD20+ B-NHL with relapsed, progressive, or refractory disease following anti-CD20 mAb treatment, and ECOG PS 0-2 were included. During dose escalation, pts received SC GEN3013 flat dose in 28-day cycles (q1w: cycle 1-2; q2w: cycle 3-6; q4w thereafter) until disease progression or unacceptable toxicity. Risk of cytokine release syndrome (CRS) was mitigated with the use of a priming dose and premedication with corticosteroids, antihistamines, and antipyretics. Primary endpoints were adverse events (AEs) and dose-limiting toxicities (DLTs). Secondary endpoints included pharmacokinetics (PK), immunogenicity (anti-drug antibodies [ADA]), pharmacodynamics (PD) (cytokine measures; laboratory parameters), and anti-tumor activity (tumor size reduction; objective and best response). Results: At data cut-off (June 28, 2019), 18 pts were enrolled into the dose-escalation part of the trial, with safety data available for pts receiving doses starting at 4 µg. Most pts had diffuse large B-cell lymphoma (DLBCL; n=14) and were heavily pre-treated; 10 pts had received ≥3 prior lines of therapy (overall median [range]: 3 [1-11]). The median age was 58.5 years (range: 21-80), and 13 pts were male. At a median follow-up of 1.9 months, pts received a median of 5 doses (range: 1-14); treatment is ongoing in 6 pts. Twelve pts discontinued treatment due to progressive disease. Six pts died (2 during treatment, 4 during survival follow-up), all due to disease progression and unrelated to treatment. The most common (n≥5) treatment-emergent AEs were pyrexia (n=8), local injection-site reactions (n=7), diarrhea (n=5), fatigue (n=5), and increased aspartate aminotransferase (n=5). The most common Grade (G) 3/4 AEs were anemia (n=3) and neutropenia (n=3). Despite increasing GEN3013 doses, all CRS events were non-severe (initial observation: 3/8 pts, G1: n=1, G2: n=2; following modification of premedication plan [corticosteroids for 3 days]: 6/10 pts, G1: n=4, G2: n=2). Increases in peripheral cytokine (IL6, IL8, IL10, IFNγ, TNFα) concentrations after GEN3013 dosing correlated with clinical symptoms of CRS in most pts. No pts had tumor lysis syndrome or neurological symptoms. No DLTs were observed. GEN3013 PK profiles reflect SC dosing; Cmax occurred 2-4 days after dosing. No ADAs were detected. PD effects following GEN3013 dosing were observed at dose levels as low as 40 µg and included rapid, complete depletion of circulating B cells (if present after prior anti-CD20 therapy) and peripheral T-cell activation and expansion. The first evidence of clinical activity was observed at a dose level of 120 µg, with complete metabolic response observed in a pt with DLBCL. Conclusions: Subcutaneously administered GEN3013, a potent CD3×CD20 bsAb, shows good tolerability and early evidence of clinical activity at low dose levels in heavily pretreated pts with relapsed or refractory B-NHL. All CRS events were non-severe and did not lead to discontinuation. No DLTs were observed. Dose escalation is ongoing; updated data will be presented. Dose expansion will begin upon determining the recommended Phase 2 dose (RP2D) (NCT03625037). Disclosures Lugtenburg: Janssen Cilag: Honoraria; Roche: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria; Servier: Consultancy, Honoraria, Research Funding; Genmab: Consultancy, Honoraria; BMS: Consultancy; Takeda: Consultancy, Honoraria, Research Funding. Mous:Bristol-Myers Squibb: Honoraria; Celgene: Honoraria; Sandoz: Honoraria; Roche: Honoraria; Abbvie: Honoraria; Takeda: Honoraria, Research Funding; Janssen Cilag: Consultancy, Honoraria; MSD: Honoraria; Gilead: Consultancy, Honoraria, Research Funding. Clausen:Abbvie: Other: Travel grant to attend ASH 2019. Johnson:Boehringer Ingelheim: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Honoraria; Epizyme: Honoraria, Research Funding; Incyte: Honoraria; Takeda: Honoraria; Genmab: Honoraria; Bristol-Myers Squibb: Honoraria; Kite: Honoraria; Novartis: Honoraria. Rule:Janssen: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Astra-Zeneca: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Napp: Consultancy; Kite: Consultancy. Oliveri:Genmab: Employment, Equity Ownership. DeMarco:Genmab: Employment, Equity Ownership. Hiemstra:Genmab: Employment, Equity Ownership, Other: Warrants. Chen:Genmab: Employment. Azaryan:Genmab: Employment. Gupta:Genmab: Employment, Equity Ownership. Ahmadi:Genmab Inc: Employment, Other: stock and/or warrants. Hutchings:Incyte: Research Funding; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Genmab: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Janssen: Research Funding; Pfizer: Research Funding.

scholarly journals CLL B Cells Develop Resistance to Ibrutinib By Reinvigorating the IL-4R - IL-4 Axis Blocked By Bruton's Tyrosine Kinase Inhibitors Including Acalabrutinib and Zanubrutinib

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 477-477
Author(s):  
Shih-Shih Chen ◽  
Constantine S. Tam ◽  
Alan G. Ramsay ◽  
Priyadarshini Ravichandran ◽  
Natalia C. Couto-Francisco ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Cell Subset ◽  
Advisory Committees

Bruton's tyrosine kinases inhibitors (BTKis) represent major advances in CLL therapy. However resistance to this form of therapy is emerging, and such patients often progress more rapidly. Hence there is an important need for therapies that address resistance. Microenvironmental input like IL-4 is critical for CLL disease progression. Compared with normal B cells, CLL cells exhibit significantly higher levels of surface membrane (sm) IL-4 receptor (IL4-R) and contain increased amounts of pSTAT6, a downstream mediator of IL-4R signaling. IL-4 stimulation of CLL B cells suppresses smCXCR4 and increases smIgM, thus promotes CLL cell retention and expansion. In this study, we aimed to examine if smIL-4R expression, IL4R signaling, and IL-4-producing cells are altered in patients sensitive or resistant to BTKis. To do so, T and B cell subset changes were studied overtime in 12 acalabrutinib-treated CLL patients, 6 zanubrutinib-treated CLL patients, 30 ibrutinib-sensitive and 5 ibrutinib-resistant CLL patients, 4 of which exhibited BTK mutations. Consistent with only ibrutinib inhibiting T-cell kinase (ITK), T-cell subset analyses revealed no changes in Th1, Th2, Th17, Th9, and Th22 cells after zanubrutinib or acalabrutinib treatment. In contrast, a Th1-biased T-cell immunity was observed in patients responsive to ibrutinib. In patients progressing on ibrutinib, significantly reduced Th2 T cells were found during the resistant as well as sensitive periods. In an in vitro T-cell function assay using T cells collected before and after the treatment with each BTKi, only ibrutinib treated patients exhibited a reduced ability of T cells to support CLL B cell survival. We next studied changes in CLL B cells, including numbers of IL-4, -10 and -13 producing B cells after BTKi treatment. IL-13 producing CLL B cells were not changed. IL-10 producing CLL B cells were reduced in both ibrutinib sensitive and resistant patients, but not in zanubrutinib or acalabrutinib treated patients. Importantly, IL-4 producing CLL B cells were significantly decreased in patients treated with all 3 BTKi. Significantly reduced smIL-4R levels, impaired IL-4R signaling, decreased smIgM and increased smCXCR4 were also seen in patients treated with each BTKi. To understand the mechanism responsible for inhibition of IL-4 production in CLL cells treated with BTKis, we stimulated CLL cells through IgM, Toll-like receptor and CD40L, finding that only anti-IgM stimulation significantly increased IL-4 production and p-STAT6 induction. We then explored the function of IL-4. IL-4 enhanced CLL B cell survival in vitro and this action was blocked by all 3 BTKis. Moreover, adhesion of CLL B cells to smIL-4R expressing stromal cells was decreased by IL-4 and IL-4R neutralizing antibodies, especially in M-CLL cases. In in vivo studies transferring autologous T cells and CLL PBMCs into alymphoid mice, we found less CLL B cells in mouse spleens post ibrutinib than zanubrutinib or acalabrutinib treatment. This might be due to the suppressed Th2 cells found only in ibrutinib, while IL-4 producing B cells were reduced in all 3 BTKi treated mice. These results support the idea that IL-4 promotes CLL B cell adhesion and growth in tissues. Finally, we investigated the IL-4/IL-4R axis in ibrutinib-resistant patients. Although IL-4 producing T cells remain reduced during the sensitive and resistant phases, CLL B cell production of IL-4 and expression of and signaling through smIL-4R returned when patients developed ibrutinib-resistance. When comparing paired ibrutinib-sensitive and -resistant CLL B cells collected from 3 patients in a xenograft model that requires T cell help, we found ibrutinib-resistant CLL B cells grew in vivo with only minimal (~15%) numbers of autologous T cells compared to B cells collected from ibrutinib-sensitive phase; this suggested a reduced requirement for T-cell help for growth of ibrutinib-resistant CLL cells. In summary, we found IL-4 is a key survival factor in the CLL microenvironment that also improves leukemia cell adhesion to stromal cells expressing smIL-4R. IL-4 production and signaling can be stimulated in CLL B cells through the B-cell receptor, and are consistently blocked by BTKis. Moreover, the recovered ability of ibrutinib-resistant CLL B cells to produce and respond to IL-4 leads to disease progression, suggesting blocking the IL-4/IL-4R axis is a potential treatment for ibrutinib-resistant CLL patients. Disclosures Chen: Pharmacyclics: Research Funding; Beigene: Research Funding; Verastem: Research Funding; ArgenX: Research Funding. Tam:Abbvie, Janssen: Research Funding; Abbvie, Janssen, Beigene, Roche, Novartis: Honoraria. Ramsay:Celgene Corporation: Research Funding; Roche Glycart AG: Research Funding. Kolitz:Boeringer-Ingelheim: Research Funding; Roche: Research Funding; Astellas: Research Funding. Zhou:BeiGene: Employment. Barrientos:Genentech: Consultancy; Gilead: Consultancy; Janssen: Consultancy; Abbvie: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding. Rai:Pharmacyctics: Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Membership on an entity's Board of Directors or advisory committees; Cellectis: Membership on an entity's Board of Directors or advisory committees; Genentech/Roche: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Genomics Reveal Potential Biomarkers of Response to Pembrolizumab after High Dose Cytarabine in an Ongoing Phase II Trial in Relapsed/Refractory AML

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4054-4054 ◽  
Author(s):  
Joshua F Zeidner ◽  
Benjamin G. Vincent ◽  
Anastasia Ivanova ◽  
Matthew C Foster ◽  
Catherine C. Coombs ◽  
...  
Keyword(s):  
Cell Cycle ◽  
T Cell ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Maintenance Phase ◽  
Amplicon Sequencing ◽  
Cell Receptor ◽  
High Dose ◽  
Advisory Committees

Abstract Background: Outcomes remain dismal for patients (pts) with relapsed/refractory (R/R) AML. Programmed Death-1 (PD-1), an inhibitory receptor on T and B cells, suppresses immune activation. We hypothesized that administration of pembrolizumab, a monoclonal antibody targeting PD-1, after high dose cytarabine (HiDAC) salvage chemotherapy would stimulate a T-cell mediated anti-leukemic immune response leading to improved efficacy in R/R AML. Methods: We are conducting a multicenter phase II study of HiDAC (<60 years: 2 gm/m2 IV Q12hours days 1-5; ≥60 years: 1.5 gm/m2 IV Q12hours days 1-5) followed by pembrolizumab 200 mg IV on day 14 in R/R AML pts 18-70 years. The primary objective of this study is to estimate the overall complete remission (CR + CRi) rate. Overall responders can receive maintenance phase pembrolizumab 200 mg IV Q3weeks for up to 2 years until progression. Allogeneic stem cell transplant (SCT) is permissible before or after maintenance phase. Results: To date, 26 pts are evaluable for safety and response (Table 1). Grade ≥3 immune-related adverse events have been rare and self-limiting. The overall CR rate is 35%. Of the 9 CR pts, 5 (56%) had no evidence of minimal residual disease (MRD) by standard monitoring. Notably, 2/3 primary refractory pts with inv(3) cytogenetics achieved CR and underwent SCT. Additionally, 1 pt with relapsed AML with most recent treatment refractory to HiDAC salvage achieved CR with no evidence of MRD. Five pts received maintenance pembrolizumab: 3 relapsed (median duration of CR = 2.8 months; range: 2-5.7 months), 1 proceeded to SCT after 2 cycles, and 1 initially achieved a partial remission (PR) and had stable disease for 12 cycles of maintenance pembrolizumab before progressing. Four pts received a SCT in CR (n=3) and morphologic leukemia free state (MLFS) (n=1). Grade II acute graft-versus host disease (GVHD) and moderate chronic GVHD was seen in 2/4 (50%) pts, respectively. With a median follow up of 10.8 months to date, median overall survival is 10.5 months (range: 1.8-20.8 months). We performed B cell receptor amplicon sequencing, T cell receptor (TCR) amplicon sequencing from CD8+ T cells, and RNA-seq from enriched blasts and non-blast fractions in bone marrow (BM) from 3 CR and 3 non-responders (NR) prior to HiDAC. From the BM blast enriched fraction, expression of innate immune genes such as NLRP12, C3, S100A9, S100A12 and CD14 correlated with response. Gene Set Enrichment Analysis (GSEA) demonstrated that CR correlated with expression of genes in the Toll Pathway, Lysosome pathway, and adaptive immune system while NRs were associated with expression of the PAR1 and GATA3 pathways. From the non-blast BM population, CR correlated with expression of cell-cycle genes such as CCNE1, CCNB2, E2F2, KIF18B and CDKN3. Not surprisingly, GSEA revealed that expression of cell cycle pathways correlated with response. CR correlated with increased expression of B cell metagenes and the inverse IPRES signature in the non-blast BM fraction. As previously reported, there was a significant increase in peripheral blood (PB) TCR diversity in CR pts. CR was also significantly associated with the abundance and richness of the non-blast BM fraction of the B cell heavy and both light chains suggesting that a broader immune response at baseline may be critical for response to HiDAC and pembrolizumab. Finally, CR correlated with increased expression of CD300E, CCR7, CCR4, CCR8 and CCL7 in PB CD8+ T cells suggesting that migration of monocytes, T and B cells is associated with response. Conclusions: Our findings demonstrate that pembrolizumab is well tolerated after HiDAC in an ongoing study in R/R AML. An encouraging response rate has been seen in a high-risk patient population without apparent additive toxicity post-SCT. Our RNA-seq and amplicon sequencing data indicate that biomarkers of response are present prior to therapy. Increased expression of innate immune genes expressed by leukemic blasts and cell cycle genes by the non-blast fraction correlated with response to therapy. Additionally, CR was associated with increased measures of B and T cell diversity and immune cell migration. Further immunogenomic biomarker correlates are ongoing to determine predictors of response to pembrolizumab after HiDAC in R/R AML. Disclosures Zeidner: Tolero: Honoraria, Other: Travel Fees, Research Funding; Asystbio Laboratories: Consultancy; Merck: Research Funding; Takeda: Other: Travel fees, Research Funding; Rafael Pharmaceuticals: Other: Travel Fees; Celgene: Honoraria. Vincent:Merck: Research Funding. Foster:Celgene: Research Funding; Macrogenics: Research Funding; Pfizer: Research Funding; Shire: Honoraria. Coombs:Incyte: Other: Travel fees; AROG: Other: Travel fees; DAVA Oncology: Honoraria; Abbvie: Consultancy; H3 Biomedicine: Honoraria. Luznik:WIndMIL Therapeutics: Equity Ownership, Patents & Royalties. Gojo:Merck inc: Research Funding; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees. Serody:Merck: Research Funding.

scholarly journals Waldenström's Macroglobulinemia (WM) Is Preceded By Clonal Lymphopoiesis Including MYD88 L265P in Progenitor B Cells

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1527-1527
Author(s):  
Sara Rodríguez ◽  
Cirino Botta ◽  
Jon Celay ◽  
Ibai Goicoechea ◽  
Maria J Garcia-Barchino ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Somatic Mutations ◽  
Advisory Committees ◽  
Normal Cells ◽  
Cell Clones ◽  
B Cell Precursors ◽  
Myd88 L265p

Background: Although MYD88 L265P is highly frequent in WM, by itself is insufficient to explain disease progression since most cases with IgM MGUS also have mutated MYD88. In fact, the percentage of MYD88 L265P in CD19+ cells isolated from WM patients is typically &lt;100%, which questions if this mutation initiates the formation of B-cell clones. Furthermore, a few WM patients have detectable MYD88 L265P in total bone marrow (BM) cells and not in CD19+ selected B cells, raising the possibility that other hematopoietic cells carry the MYD88 mutation. However, no one has investigated if the pathogenesis of WM is related to somatic mutations occurring at the hematopoietic stem cell level, similarly to what has been shown in CLL or hairy cell leukemia. Aim: Define the cellular origin of WM by comparing the genetic landscape of WM cells to that of CD34 progenitors, B cell precursors and residual normal B cells. Methods: We used multidimensional FACSorting to isolate a total of 43 cell subsets from BM aspirates of 8 WM patients: CD34+ progenitors, B cell precursors, residual normal B cells (if detectable), WM B cells, plasma cells (PCs) and T cells (germline control). Whole-exome sequencing (WES, mean depth 74x) was performed with the 10XGenomics Exome Solution for low DNA-input due to very low numbers of some cell types. We also performed single-cell RNA and B-cell receptor sequencing (scRNA/BCRseq) in total BM B cells and PCs (n=32,720) from 3 IgM MGUS and 2 WM patients. Accordingly, the clonotypic BCR detected in WM cells was unbiasedly investigated in all B cell maturation stages defined according to their molecular phenotype. In parallel, MYD88p.L252P (orthologous position of the human L265P mutation) transgenic mice were crossed with conditional Sca1Cre, Mb1Cre, and Cγ1Cre mice to selectively induce in vivo expression of MYD88 mutation in CD34 progenitors, B cell precursors and germinal center B cells, respectively. Upon immunization, mice from each cohort were necropsied at 5, 10 and 15 months of age and screened for the presence of hematological disease. Results: All 8 WM patients showed MYD88 L265P and 3 had mutated CXCR4. Notably, we found MYD88 L265P in B cell precursors from 1/8 cases and in residual normal B cells from 3/8 patients, which were confirmed by ASO-PCR. In addition, CXCR4 was simultaneously mutated in B cell precursors and WM B cells from one patient. Overall, CD34+ progenitors, B-cell precursors and residual normal B cells shared a median of 1 (range, 0-4; mean VAF, 0.16), 2 (range, 1-5; mean VAF, 0.14), and 4 (range, 1-13; mean VAF, 0.26) non-synonymous mutations with WM B cells. Some mutations were found all the way from CD34+ progenitors to WM B cells and PCs. Interestingly, concordance between the mutational landscape of WM B cells and PCs was &lt;100% (median of 85%, range: 25%-100%), suggesting that not all WB B cells differentiate into PCs. A median of 7 (range, 2-19; mean VAF, 0.39) mutations were unique to WM B cells. Accordingly, many clonal mutations in WM B cells were undetectable in normal cells. Thus, the few somatic mutations observed in patients' lymphopoiesis could not result from contamination during FACSorting since in such cases, all clonal mutations would be detectable in normal cells. Of note, while somatic mutations were systematically detected in normal cells from all patients, no copy number alterations (CNA) present in WM cells were detectable in normal cells. scRNA/BCRseq unveiled that clonotypic cells were confined mostly within mature B cell and PC clusters in IgM MGUS, whereas a fraction of clonotypic cells from WM patients showed a transcriptional profile overlapping with that of B cell precursors. In mice, induced expression of mutated MYD88 led to a moderate increase in the number of B220+CD138+ plasmablasts and B220-CD138+ PCs in lymphoid tissues and BM, but no signs of clonality or hematological disease. Interestingly, such increment was more evident in mice with activation of mutated MYD88 in CD34+ progenitors and B-cell precursors vs mice with MYD88 L252P induced in germinal center B cells. Conclusions: We show for the first time that WM patients have somatic mutations, including MYD88 L265P and in CXCR4, at the B cell progenitor level. Taken together, this study suggests that in some patients, WM could develop from B cell clones carrying MYD88 L265P rather than it being the initiating event, and that other mutations or CNA are required for the expansion of B cells and PCs with the WM phenotype. Disclosures Roccaro: Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Transcan2-ERANET: Research Funding; AstraZeneca: Research Funding; European Hematology Association: Research Funding; Transcan2-ERANET: Research Funding; Associazione Italiana per al Ricerca sul Cancro (AIRC): Research Funding; Associazione Italiana per al Ricerca sul Cancro (AIRC): Research Funding; European Hematology Association: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees. San-Miguel:Amgen, Bristol-Myers Squibb, Celgene, Janssen, MSD, Novartis, Roche, Sanofi, and Takeda: Consultancy, Honoraria. Paiva:Amgen, Bristol-Myers Squibb, Celgene, Janssen, Merck, Novartis, Roche, and Sanofi; unrestricted grants from Celgene, EngMab, Sanofi, and Takeda; and consultancy for Celgene, Janssen, and Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau.

scholarly journals Chromosomal Translocation t(11;14) Induced By the Cre-Loxp System in Normal B Cell-Derived Ips Cells for the Study of Myeloma-Initiating Cells

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 18-19
Author(s):  
Misaki Sugai ◽  
Naohiro Tsuyama ◽  
Yu Abe ◽  
Yusuke Azami ◽  
Kenichi Kudo ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Board Of Directors ◽  
B Lymphocytes ◽  
Research Funding ◽  
Chromosomal Translocation ◽  
Stem Cell Differentiation ◽  
Advisory Committees ◽  
Myeloma Cells ◽  
Company Limited

The cellular origin of multiple myeloma (MM) has not yet been identified. Based on immunoglobulin heavy chain (IgH) gene analysis, myeloma cells are derived from mature B cells. Chromosomal aberrations such as trisomy and chromosomal translocation (cTr) play a critical role in the early tumorigenesis of MM. We hypothesized that the abnormal cells from which myeloma cells originate might be mature B lymphocytes with chromosomal or genetic changes in the reprogrammed state that enable them to acquire the potential to become tumors in the process of redifferentiation into B lymphocytes. We established induced pluripotent stem cells (iPSs) from normal B lymphocytes (BiPSCs: BiPSC13 & MIB2-6); these BiPSCs have the same VDJ rearrangement of IgH as the original B lymphocytes and differentiate into CD34+/CD38- hematopoietic progenitor cells co-culture with stromal cells, AGM-S3 (Sci Rep, 2017). We then established a method to induce reciprocal cTr t(11;14), which is a reciprocal cTr between IgH and CCND1 and the most frequent cTr in MM, using the CRISPR/Cas9 system; cTr was induced by infection of IgH-CCND1 lentiCRISPRv2 lentivirus, which targets the human IgH Eµ region and 13kb upstream of the CCND1 coding sequence, to BiPSCs (Oncol Lett, 2019). Subsequently, we established cell lines carrying reciprocal cTr t(11;14) between CCND1 and either an allele in which VDJ rearrangement of IgH had been completed or an allele in which VDJ rearrangement had not been completed (stopped at DJ joining) in BiPSC13 t(11;14) (AZ & AX) and MIB2-6 t(11;14) (BC & BG), respectively. These BiPSCs differentiated into CD34+/CD38-/CD45+/-/CD43+/- hematopoietic progenitors cells in co-culture with AGM-S3 or in stem cell differentiation medium; this was subsequently confirmed by the differentiation into granulocytes, macrophages, and erythroblasts in a colony-formation assay. We are now trying to produce BiPSCs in which cTr t(11;14) is induced when they differentiate into mature B cells expressing CD27. First, we used the Cre-loxP recombination system to induce cTr t(11;14) in BiPSCs. BiPSCs were transfected with IgH loxP-Neo-loxP knock-in vector and IgH lentiCRISPRv2 vector. Subsequently, G418-resistant BiPSCs carrying loxP-Neo-loxP in IgH were transfected with iCre-EGFP. After removing the loxP-Neo site from EGFP-positive cells, BiPSCs carrying IgH-loxP were transfected with CCND1 loxP-FRT3-Neo-FRT3 knock-in vector and CCND1 lentiCRISPRv2 vector. Subsequently, G418-resistant BiPSCs carrying IgH-loxP in IgH and loxP-FRT3-Neo-FRT3 in CCND1 were transfected with Flpo-EGFP. After removing the FRT3-Neo site from EGFP-positive cells, BiPSCs carrying IgH-loxP in IgH and CCND1-loxP-FRT3 in CCND1 were transfected with iCre-HygR. Hygromycin B-resistant cells were picked, the reciprocal cTr t(11;14) was confirmed by polymerase chain reaction, and we established BiPSCs with der(11)t(11;14) and BiPSCs with der(14)t(11;14). We also developed a system in which Cre is expressed along with CD27 expression in the B cell lymphoma cell line Raji. These BiPSCs could be useful for the study of myeloma-initiating cells, but whether they would be able to be redifferentiated into B lymphocyte is important. Disclosures Hanamura: Mundipharma K.K.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; CSL Behring: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD K.K.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi K.K.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SHIONOGI Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis Pharma K.K.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; DAIICHI SANKYO COMPANY, LIMITED: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eisai Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; NIPPON SHINYAKU CO.,LTD.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer Japan Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda Pharmaceutical Company Limited: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen Pharmaceutical K.K.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Ono Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Comprehensive Oncology Measures for Peripheral T-Cell Lymphoma Treatment (COMPLETE): First Detailed Report of Primary Treatment

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1614-1614 ◽  
Author(s):  
Francine M. Foss ◽  
Kenneth R. Carson ◽  
Lauren Pinter-Brown ◽  
Steven M. Horwitz ◽  
Steven T. Rosen ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Board Of Directors ◽  
Initial Treatment ◽  
Research Funding ◽  
Cell Lymphoma ◽  
Primary Treatment ◽  
T Cell Lymphoma ◽  
Peripheral T Cell Lymphoma ◽  
Advisory Committees

Abstract 1614 Background: Registries can be invaluable for describing patterns of care for a population of patients. COMPLETE is a registry of peripheral T-cell lymphoma (PTCL) patients designed to identify the lymphoma-directed treatments and supportive care measures that PTCL patients receive. We report here the first detailed findings of initial therapy. Methods: This is a prospective, longitudinal, observational registry that is led by a global steering committee. Patients with newly diagnosed PTCL and providing written informed consent are eligible. Patients are entered into the registry from time of initial diagnosis and followed for up to 5 years. Only locked records are reported. Results: As of July 2012, 330 patients have been enrolled from the United States. The first patient was enrolled in February 2010. Locked baseline and treatment records are available for 124 and 81 patients, respectively. Of the 124 patients with locked baseline records, 67 patients (54%) were male, the mean age was 59 (range: 19–89), and race/ethnicity was recorded as: White (87 patients; 70%), Black (19; 15%), Asian (5; 4%) and other/unknown (13; 11%). Histology was reported as follows: PTCL-not otherwise specified (27%), anaplastic large cell lymphoma-primary systemic type (18%), angioimmunoblastic T-cell lymphoma (17%), transformed mycosis fungoides (7%), T/NK-cell lymphoma-nasal and nasal type (6%), adult T-cell leukemia/lymphoma, HTLV 1+ (6%) and other (19%). 25 patients (20%) had received another diagnosis, including B-cell lymphoma, Hodgkin's disease and other T-cell lymphomas, prior to their current diagnosis of PTCL. 49 patients (40%) had B symptoms, 102 patients (82%) had an Ann Arbor stage of III/IV, 116 patients (94%) had ECOG performance status of 0–1, and international prognostic index (IPI) score was distributed as follows: IPI 0 (7% of patients), 1 (15%), 2 (43%), 3 (26%), and 4 (9%). Of the 81 patients with locked treatment records, details on initial treatment can be found in table below. Conclusions: This first detailed analysis of primary treatment of PTCL indicates that this disease is still largely being treated with regimens derived primarily from studies of B-cell lymphomas and that a single standard of care does not exist. The fact that a meaningful proportion of patients were initially diagnosed with something other than their current diagnosis of PTCL points out the challenges of diagnosing the disease. While the intent of initial treatment for most patients is to affect a cure, more than 20% of patients were noted as deceased at the end of initial treatment, underscoring the need for more effective, disease-specific therapy. Disclosures: Foss: Merck: Study Grant, Study Grant Other; Celgene: Study Grant, Study Grant Other; Eisai: Consultancy; Seattle Genetics: Consultancy; Celgene: Consultancy; Allos: Consultancy. Carson:Allos: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. Pinter-Brown:Allos: Consultancy, Membership on an entity's Board of Directors or advisory committees. Horwitz:Allos: Consultancy, Research Funding. Rosen:Allos: Consultancy, Honoraria. Pro:Celgene: Honoraria, Research Funding; Spectrum: Honoraria; Allos: Honoraria; Seattle Genetics: Research Funding. Gisselbrecht:Allos: Consultancy, Membership on an entity's Board of Directors or advisory committees. Hsi:Allos: Research Funding; Eli Lilly: Research Funding; Abbott: Research Funding; Cellerant Therapeutics: Research Funding; BD Biosciences: Research Funding; Millenium: Research Funding.

Phase I/Ib Study of the Novel Immunotoxin MT-3724 in Relapsed/Refractory Non-Hodgkin's B-Cell Lymphoma (NHL)

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 5112-5112
Author(s):  
Paul A Hamlin ◽  
Catherine S. Diefenbach ◽  
David J. Valacer ◽  
Jack Higgins ◽  
Michelle A. Fanale
Keyword(s):  
B Cells ◽  
Phase I ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
B Cell Lymphoma ◽  
Advisory Committees ◽  
Dose Cohort ◽  
Mixed Response

Abstract Background CD20 is selectively expressed on the surface of early pre-B-cells, remains throughout B-cell development, and is then lost from plasma cells. Because CD20 is present on the majority of B-cell lymphomas, anti-CD20 monoclonal antibody (MAb) therapy is widely employed in the treatment of NHL. However a majority of NHL patients eventually become refractory to CD20 MAb(s). Resistance mechanisms may include increased MAb catabolism, initial or post treatment selection of low CD20 expressing tumor cells, trogocytosis of surface CD20, failure of MAb effector mechanisms and/or impaired patient immune cell function. MT-3724 is a recombinant fusion protein consisting of a CD20 binding variable fragment (scFv) fused to the enzymatically active Shiga-like toxin-I A1 subunit (SLT-I A1). SLT-I A1 is an N-glycosidase that catalytically inactivates 60S ribosomal subunits causing inhibition of protein synthesis. Upon its scFv binding to cell surface CD20 in vitro, SLT-I A1 forces MT-3724 internalization which then routes in a predictable fashion to the cytosol and irreversibly inactivates the cell ribosomes triggering cell death. MT-3724 has been shown to specifically bind and kill CD20+ malignant human B-cells in vitro and non-human primate (NHP) B-cells in vivo. MT-3724 was tested for safety in healthy NHPs: 6 intravenous (IV) doses of MT-3724 were given over 12 days at doses of 50, 150, and 450 mcg/kg. There were no deaths or effects on serum chemistries in the NHP studies. The major observed toxicity (inappetence) resolved within 48 hours of last dose. There was a significant, dose-dependent NHP B-cell depletion by Day 3 at all doses. Given the preclinical activity and mechanism of action, a Phase I/Ib study of MT-3724 was initiated in NHL. Methods MT-3724 is being tested for safety and tolerability in a first-in-human, open label, ascending dose study (3 + 3 design) in sequential cohorts of 5, 10, 20 and 50 mcg/kg/dose. Eligible subjects who previously responded to a CD20 MAb containing therapy followed by relapse/recurrence of NHL receive 6 doses by 2 hour IV infusions over the first 12 days of a 28 day cycle (first cycle). With continued safety, tolerability and lack of tumor progression, subjects may receive up to 4 additional 6-dose cycles (21 days) with tumor assessments after cycles 2, 4 and 5. Dose escalation is based on < 33% dose limiting toxicities (DLTs) observed during the first 28 day cycle. Results Three NHL subjects (2 transformed DLBCL, 1 FL) have completed at least one cycle in the 5 mcg/kg/dose cohort with no protocol DLTs or infusion related reactions and are evaluable for safety. Non-DLTs included grade (Gr) 2-3 transient hyperglycemic episodes related to pre-infusion corticosteroid therapy (n=1); transient Gr 4 neutropenia, possibly related to MT-3724 during cycle 1, week 4 (n=1); Gr 4 hypercalcemia and acute kidney injury with Gr 3 hypophosphatemia during cycle 1, week 4 due to leukemic disease progression (n=1). Subject 1 completed 5 cycles of therapy, with a partial response achieved post cycle 2 sustained through cycle 5; Subject 3 had a mixed response (both subjects had transformed DLBCL). Three subjects have now initiated treatment in the 10 mcg/kg/dose cohort with updated data to be presented at the meeting. Conclusions MT-3724 at 5 mcg/kg/dose has been safely administered for up to 5 cycles in this first-in-human study in relapsed/refractory NHL subjects. Treatment with the 10 mcg/kg cohort has commenced with continuing dose ascension planned. There is early evidence of clinical activity. Disclosures Diefenbach: Gilead: Equity Ownership, Research Funding, Speakers Bureau; Jannsen Oncology: Consultancy; Idera: Consultancy; Immunogen: Consultancy; Incyte: Research Funding; Genentech: Research Funding; Celgene: Consultancy; Molecular Templates: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding. Valacer:Molecular Templates: Employment. Higgins:Molecular Templates: Employment. Fanale:Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Honoraria, Research Funding; Infinity: 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: Honoraria, Research Funding; Genentech: Research Funding; Medimmune: Research Funding; Novartis: Research Funding; Bayer: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Molecular Templates: Research Funding; ADC Therapeutics: Research Funding; Onyx: Research Funding; Gilead: Research Funding.

scholarly journals Nanatinostat (Nstat) and Valganciclovir (VGCV) in Relapsed/Refractory (R/R) Epstein-Barr Virus-Positive (EBV +) Lymphomas: Final Results from the Phase 1b/2 VT3996-201 Study

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 623-623
Author(s):  
Bradley M. Haverkos ◽  
Onder Alpdogan ◽  
Robert Baiocchi ◽  
Jonathan E Brammer ◽  
Tatyana A. Feldman ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
T Cell Lymphoma ◽  
Phase 2 ◽  
Advisory Committees ◽  
Phase 1B

Abstract Introduction: EBV can be associated with several types of lymphomas, with reported frequencies of up to 8-10% in diffuse large B cell lymphoma (DLBCL), 30-100% in peripheral T cell lymphoma (PTCL) subtypes, 80% in post-transplant lymphoproliferative disease (PTLD), and 15-30% in classical Hodgkin lymphoma (HL), with adverse impact on outcomes. Nanatinostat (Nstat) is a Class-I selective oral HDAC inhibitor that induces the expression of the lytic BGLF4 EBV protein kinase in EBV + tumor cells, activating ganciclovir (GCV) via phosphorylation. This results in GCV-induced inhibition of viral and cellular DNA synthesis and apoptosis. Herein we report the final results from this exploratory study for patients with R/R EBV + lymphomas (NCT03397706). Methods: Patients aged ≥18 with histologically confirmed EBV + lymphomas (defined as any degree of EBER-ISH positivity), R/R to ≥1 prior systemic therapies with an absolute neutrophil count ≥1.0×10 9/L, platelet count ≥50×10 9/L, and no curative treatment options per investigator were enrolled into 5 dose escalation cohorts to determine the recommended phase 2 doses (RP2D) of Nstat + VGCV for phase 2 expansion. Phase 2 patients received the RP2D (Nstat 20 mg daily, 4 days per week + VGCV 900 mg orally daily) in 28-day cycles until disease progression or withdrawal. Primary endpoints were safety/RP2D (phase 1b) and overall response rate (ORR) (phase 2); secondary endpoints were pharmacokinetics, duration of response (DoR), time to response, progression free survival and overall survival. Responses were assessed using Lugano 2014 response criteria beginning at week 8. Results: As of 18 June 2021, 55 patients were enrolled (phase 1b: 25; phase 2: 30). Lymphoma subtypes were DLBCL (n=7), extranodal NK/T-cell (ENKTL) (n=9), PTCL, not otherwise specified (PTCL-NOS) (n=5), angioimmunoblastic T cell lymphoma (n=6), cutaneous T cell (n=1), HL (n=11), other B cell (n=3), and immunodeficiency-associated lymphoproliferative disorders (IA-LPD) (n=13), including PTLD (n=4), HIV-associated (n=5), and other [n=4: systemic lupus erythematosus (SLE) (n=2), common variable/primary immunodeficiency (n=2)]. Median age was 60 years (range 19-84), M/F 35/20, median number of prior therapies was 2 (range 1-11), 76% had ≥2 prior therapies, 78% were refractory to their most recent prior therapy, and 84% had exhausted standard therapies. EBER positivity ranged from &lt;1 to 90% in 42 tumor biopsies with central lab review. The most common treatment-emergent adverse events (TEAEs) of all grades were nausea (38%), neutropenia (34%), thrombocytopenia (34%), and constipation (31%). Grade 3/4 TEAEs in &gt;10% of patients included neutropenia (27%), thrombocytopenia (20%), anemia (20%), and lymphopenia (14%). Dose reductions and interruptions due to treatment-related AEs were reported in 14 (25%) and 16 (29%) patients, respectively. Only 1 patient had to discontinue therapy. There were no cases of CMV reactivation. For 43 evaluable patients (EBER-ISH + with ≥ 1 post-treatment response assessment) across all histologies, the investigator-assessed ORR and complete response (CR) rates were 40% (17/43) and 19% (8/43) respectively. Patients with T/NK-NHL (n=15; all refractory to their last therapy) had an ORR of 60% (n=9) with 27% (n=4) CRs. Two patients (ENKTL and PTCL-NOS) in PR and CR respectively were withdrawn at 6.7 and 6.6 months (m) respectively for autologous stem cell transplantation. For DLBCL (n=6), ORR/CR was 67%/33% (both CRs were in patients refractory to first-line R-CHOP). For IA-LPD (n=13), ORR/CR was 30%/20% (PTLD: 1 CR, other: 1 CR, 1 PR). For HL (n=10), there was 1 PR (4 SD). The median DoR for all responders was 10.4 m, with a median follow-up from response of 5.7 m (range 1.9-34.1 m). For the 17 responders, 8 lasted ≥ 6 months. Conclusions: The combination of Nstat and VGCV was well-tolerated with a manageable toxicity profile and shows promising efficacy in patients with R/R EBV + lymphomas, particularly in refractory T/NK-NHL, a heterogeneous group of aggressive lymphomas with dismal outcomes, with multiple durable responses. Further evaluation of this novel combination therapy for the treatment of recurrent EBV + lymphomas is ongoing in the phase 2 VT3996-202 trial. Disclosures Haverkos: Viracta Therapeutics, Inc.: Honoraria, Research Funding. Baiocchi: Prelude Therapeutics: Consultancy; viracta: Consultancy, Current holder of stock options in a privately-held company; Codiak Biosciences: Research Funding; Atara Biotherapeutics: Consultancy. Brammer: Seattle Genetics: Speakers Bureau; Celgene: Research Funding; Kymera Therapeutics: Consultancy. Feldman: Alexion, AstraZeneca Rare Disease: Honoraria, Other: Study investigator. Brem: Karyopharm: Membership on an entity's Board of Directors or advisory committees; SeaGen: Speakers Bureau; BeiGene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees; KiTE Pharma: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Consultancy; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Morphosys/Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Scheinberg: Roche: Consultancy; Abbvie: Consultancy; BioCryst Pharmaceuticals: Consultancy; Alexion pharmaceuticals: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau. Joffe: AstraZeneca: Consultancy; Epizyme: Consultancy. Katkov: Viracta Therapeutics, Inc.: Current Employment. McRae: Viracta Therapeutics, Inc.: Current Employment. Royston: Viracta Therapeutics, Inc.: Current Employment. Rojkjaer: Viracta Therapeutics, Inc.: Current Employment. Porcu: Viracta: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Innate Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BeiGene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Research Funding; Daiichi: Honoraria, Research Funding; Kiowa: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Spectrum: Consultancy; DrenBio: Consultancy.

scholarly journals Modeling of the Epigenome of the Cell-of-Origin Identifies Cancer-Specific DNA Methylation Patterns in CLL

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3885-3885
Author(s):  
Justyna Anna Wierzbinska ◽  
Reka Toth ◽  
Naveed Ishaque ◽  
Jan-Phillip Mallm ◽  
Karsten Rippe ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
B Cell Differentiation ◽  
Advisory Committees ◽  
Normal Differentiation ◽  
Methylation Patterns

Abstract Normal B cells undergo extensive epigenetic programming during normal differentiation and distinct B cell differentiation stages represent unique DNA methylation patterns. Chronic Lymphocytic Leukemia (CLL) originates from rapidly differentiating B cells and their DNA methylation signature is stably propagated in CLL. Consequently, CLL methylome data can be used to infer the putative cell-of-origin (COO) for each individual CLL case. We define the COO of CLL as the cell that has acquired a first oncogenic hit and which will initiate tumorigenic growth if one or more additional hits have been acquired. This means that two factors contribute to the epigenetic profile of CLL cells: first, the epigenetic profile of the founder B cell at the time of malignant transformation and second, CLL-specific epigenetic alterations that are acquired during leukemogenesis and progression of the disease. Previous studies using peripheral blood CD19+ B cells as a reference for aberrant methylation calls completely neglected the massive epigenetic programming that occurs during normal B cell differentiation. Thus, novel strategies aiming at identifying truly CLL-specific methylation changes considering the highly dynamic methylome during normal B cell differentiation were urgently needed. Here we outline a new analytical framework to delineate CLL-specific DNA methylation. We demonstrate how this approach can be applied to detect epigenetically deregulated transcripts in CLL. Firstly, we modeled the epigenome dynamics occurring during normal B cell differentiation using linear regression. The DNA methylomes of CLL cells were then precisely positioned onto the normal B cell differentiation trajectory to define the closest normal B cell methylome for every CLL patient, the COO. The epigenome of the COO then served as a reference for aberrant DNA methylation calls. We dissected two categories of CLL-specific methylation events: those occurring at sites undergoing epigenetic programming during B cell differentiation and those that normally do not change during B cell differentiation. The first group was further subdivided into class A and B, displaying exaggerated methylation loss or gain, respectively, and class C showing both hyper- and hypomethylation relative to the normal differentiation. The second group was classified into class D displaying hypo- and class E showing hypermethylation. Overall, only 1.6% of the CpG-sites (7,248 CpGs) represented on the Illumina 450k array were affected by disease-specific methylation programming, mostly hypomethylation (6,680 CpGs). Next, the molecular programs underlying the CLL-specific methylation patterns were investigated. We tested enrichment of chromatin states and of transcription factor binding sites (TFBS) as identified in an immortalized B cell line (GM12878). This indicated that disease-specific methylation events target transcriptionally relevant cis-regulatory elements in CLL (enhancers, weak and poised promoters and insulator regions). In line with this, CLL-specific differentially methylated regions affected TFBS associated with signaling pathways known to be important in normal B-cell differentiation (i.e. BATF, EBF1). We also observed altered methylation at CTCF binding sites suggesting their involvement in CLL pathogenesis. In the present work, we dissected CLL methylomes to distinguish between normal B cell differentiation-associated methylation patterns and CLL-specific methylation events. We showed that this approach is indispensable to identify key pathogenic events driving CLL pathogenesis. The relevance of our approach was demonstrated by contrasting the number of epigenetically deregulated miRNAs and protein-coding genes to those determined with a classic analysis using CD19+ B cells as controls. This highlights the extent of overcalling of CLL-specific methylation patterns in previous studies (~30-fold for protein-coding genes and ~10-fold for miRNAs) and stresses the importance to consider normal differentiation trajectories for the identification of aberrant DNA methylation events. Here we propose 11 protein-coding genes (e.g. DOK2, CLLU1) and 4 miRNAs (e.g. miR-486, miR-195) as being epigenetically deregulated in CLL. Our analytical approach provides a general framework for the identification of disease-specific epigenomic changes that should be applicable to other cancers in the future. Disclosures Küppers: the Takeda Advisory Board: Membership on an entity's Board of Directors or advisory committees. Stilgenbauer:AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genzyme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmcyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Mundipharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Hoffmann La-Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

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