High-Dose IgG Alters the Relative Expression of Fcgamma RIIA and Fcgamma RIIB On Human Macrophages: A Mechanism for IVIG Therapy in Human Immune Thrombocytopenia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 683-683 ◽  
Author(s):  
Salley Pels ◽  
Caroline Tang ◽  
Mehmet Ertem ◽  
Diana S. Beardsley
Keyword(s):  
Board Of Directors ◽  
Immune Thrombocytopenia ◽  
Ivig Therapy ◽  
High Dose ◽  
Igg Antibody ◽  
Platelet Destruction ◽  
Advisory Committees ◽  
Human Macrophages ◽  
Human Immune

Abstract Abstract 683 The pathogenic mechanism of immune thrombocytopenia involves antibody mediated destruction of platelets in the reticuloendothelial system. Infection often triggers an exacerbation of thrombocytopenia in patients with ITP that may be treated with intravenous immunoglobulin (IVIG). However, the precise mechanism of action of IVIG has not been clearly elucidated. Studies by McKenzie et al. (Journal of Immunology, 1999) in an animal model for immune thrombocytopenia (ITP) using a mouse transgenic for human activating receptor FcgammaRIIA and lacking murine activating receptors FcgammaRI and FcgammaRIII revealed that human FcgammaRIIA is necessary for antibody mediated platelet destruction. (Murine macrophages lack an analogous activating FcgammaRII.) In another animal model of ITP, Samuelsson et al. (Science, 2001) showed that decreased expression of the murine inhibiting FcgammaRIIb was associated with increased platelet destruction that was not responsive to IVIG. The present studies were undertaken to test the hypothesis that human antibody mediated platelet phagocytosis depends upon the balance between the activating (FcgammaRIIA) and inhibiting (FcgammaRIIB) receptors on human macrophages and that IVIG alters this balance by increasing the expression of the inhibiting receptor. We additionally hypothesized that infection results in decreased FcgammaRIIB expression and enhanced phagocytosis that may be abrogated by IVIG. Methods: Antibody-mediated phagocytosis of platelets by THP-1 (human macrophage) cells in culture was assayed by co-incubation of THP-1 cells with anti-platelet antibody as a model for human immune mediated platelet destruction. Platelets were labeled with 5-(and 6-) carboxyfluorescein diacetate mixed isomers (CFDA) in the presence of human serum containing anti-HPA 1a IgG antibody. Macrophages that had ingested human platelets were identified by flow cytometry as previously reported. To study the mechanism of action of IVIG therapy for immune thrombocytopenia, in vitro phagocytosis was assayed after the addition of purified IgG (100mg/ml) to the THP-1 cells 30 minutes prior to exposure of the labeled platelets to anti-HPA 1a IgG antibody. The effect of LPS on platelet phagocytosis was studied as a model for infection which can exacerbate immune platelet destruction. Phagocytosis was assayed before and after incubation with LPS (1ug/ml) for 2 hours at 37 degrees Celsius. For each experiment, total FcgammaRIIA (CD32A) and FcgammaRIIB (CD32B) were determined by immunoprecipitation and immunoblotting. Results: Pretreatment with IVIG had no effect on FcgammaRIIA (n=3) expression; however, FcgammaRIIB expression increased an average of 5 fold (n=6). Addition of LPS alone resulted in marked decrease in expression of FcgammaRIIB for up to 60 minutes; however, FcgammaRIIA did not change. Experiments performed with addition of both IVIG and LPS showed that FcgammaRIIB expression remained elevated 3 fold (n=3). Following increased expression of FcgammaRIIB, IgG exposure resulted in decreased phagocytosis as assayed by flow cytometric analysis of macrophage ingestion of CFDA-labeled platelets. Antibody mediated platelet phagocytosis by THP-1 cells was enhanced 26% by LPS after a 2 hour incubation (median increase in 5 experiments; range = 14-125%.) Conclusions: Exposure to high dose IgG increased the expression of FcgammaRIIB but had no effect on FcgammaRIIA. Therefore, the net functional effect was to tip the balance toward inhibition of antibody-mediated phagocytosis, as was observed in our in vitro assay of human platelet phagocytosis. Furthermore, treatment with IgG was able to partially overcome the negative effects of LPS on expression of the inhibiting receptor, FcgammaRIIB. These data clearly support the hypothesis that the balance of the activating (FcgammaRIIA) and inhibiting (FcgammaRIIB) receptors is important in mediating the therapeutic effects of IVIG as a treatment for human immune thrombocytopenia. Disclosures: Pels: National Hemophilia Foundation-Baxter: NHF-Baxter Clinical Fellowship Awardee, Research Funding. Beardsley:ITP Foundation: Membership on an entity's Board of Directors or advisory committees; Genzyme: Consultancy; Amgen: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Dose-Dependent Iron Chelating Effects of Eltrombopag on in Vitro Human Megakaryopoiesis

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2475-2475
Author(s):  
Zhi-Jian Liu ◽  
Emoke Deschmann ◽  
Haley E. Ramsey ◽  
Henry Feldman ◽  
Bethan Psaila ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Iron Status ◽  
Physician Education ◽  
Cancer Drug ◽  
High Dose ◽  
Advisory Committees ◽  
Young Infants ◽  
Severe Reduction ◽  
Dose Dependent

Eltrombopag (ELT), a small molecular thrombopoietin (TPO) mimetic approved for children and adults, could offer a therapeutic alternative to selected neonates and young children with chronic thrombocytopenias. ELT has also been proposed as a potential anti-cancer drug due to its anti-proliferative effects in tumor cells, which are mediated by its strong iron chelating properties. This raises the potential concern that rapidly proliferating normal cells, like bone marrow cells in neonates or young infants, could also be susceptible to the anti-proliferative effects of ELT. In this study, we first assessed the responses of neonatal (cord blood, CB) and adult (peripheral blood, PB) megakaryocyte (MK) progenitors to increasing concentrations of ELT, TPO and Romiplostim (ROM) in vitro. Consistent with the previously described pattern of neonatal megakaryopoiesis, CB progenitors generated 10-times more MKs, which were of lower ploidy but had higher CD42 surface expression levels than PB-MKs. Unlike TPO or ROM, ELT exhibited dose-dependent opposing effects on in vitro megakaryopoiesis: Low concentrations (≤6µM) stimulated megakaryopoiesis, but high concentrations (30µM) suppressed MK differentiation and proliferation, as evidenced by a severe reduction in the percentage and absolute number of CD41+ cells after 7 days of culture. The toxic effects of high ELT concentrations were not abrogated by the addition of TPO at concentrations achieved in hyporegenerative thrombocytopenias (3 ng/mL), and were reproduced by the addition of the iron chelators deferoxamine (DFO) or deferiprone (DFP) at concentrations of 100µM to MK cultures, suggesting iron deficiency as a potential mechanism. To further assess the iron chelating effects of ELT in human MKs, we used the calcein assay. In K562 cells, as well as in CB MKs, ELT concentrations >10µM reduced the labile intracellular iron pool (LIP) to lower levels than the iron chelator DFP at a concentration of 200 µM, indicating the strength of ELT's iron chelating properties. These concentrations of ELT also resulted in a severe reduction of mitochondrial transmembrane potential, detected by the JC-1 assay, decreased proliferation (EdU click assay) and apoptosis (Annexin-V binding). During MK differentiation, committed MK progenitors (CD34+/CD41+ cells) were the cell population most sensitive to the antiproliferative and apoptotic effects of high-dose ELT. Next, we evaluated whether the iron status of differentiated MK progenitors would influence their responses to ELT. To test this, we generated iron-depleted and iron-repleted CB-MK progenitors by culturing CD34+ cells for 7 days in the presence of apo-transferrin (iron-free) or holo-transferrin (iron-saturated), followed by a 72 hour culture with different concentrations of ELT. These studies revealed a strong iron status/ELT dose interaction (interaction p<0.0001); In iron-depleted cultures, 30 µM ELT and 100 µM DFO similarly impaired MK expansion and induced MK apoptosis, but these effects were attenuated in iron-repleted cultures. Interestingly, iron-depleted adult PB progenitors did not show reduced MK expansion or increased apoptosis in response to 30 µM ELT, suggesting a lower susceptibility of adult megakaryopoiesis to the iron chelating effects of ELT. Taken together, these findings suggest that iron status is an important variable affecting the response to ELT, particularly in neonates and children. Disclosures Cooper: Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Rigel: Consultancy, Membership on an entity's Board of Directors or advisory committees; Principia: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Porter:Celgene: Consultancy, Honoraria; Protagonism: Honoraria; Agios: Consultancy, Honoraria; La Jolla: Honoraria; Vifor: Honoraria; Silence therapeutics: Honoraria; Bluebird bio: Consultancy, Honoraria. Bussel:Regeneron: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; argenx: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; RallyBio: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Kezar Life Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; Physician Education Resource: Speakers Bureau; 3S Bio: Speakers Bureau; Rigel: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria, Membership on an entity's Board of Directors or advisory committees; Tranquil: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Momenta Pharmaceuticals: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Dova Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; UCB: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Sola-Visner:Sysmex America, Inc.: Other: Laboratory equipment on loan, Research Funding.

scholarly journals MCT1 As Molecularly Validated Predictive Marker for Lenalidomide-Maintenance Therapy in Multiple Myeloma

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3187-3187
Author(s):  
Jacob Stroh ◽  
Anja Seckinger ◽  
Michael Heider ◽  
Ruth Eichner ◽  
Martina Emde ◽  
...  
Keyword(s):  
Gene Expression ◽  
Board Of Directors ◽  
Research Funding ◽  
Maintenance Treatment ◽  
Xenograft Model ◽  
Predictive Marker ◽  
High Dose ◽  
Advisory Committees

Introduction: Lenalidomide-based maintenance therapy is the currently approved standard of care for multiple myeloma (MM) patients after high-dose melphalan and autologous stem cell transplantation (HD-Mel), which significantly prolongs progression-free (PFS) and overall survival (OS). For patients with del17p bortezomib based maintenance treatment is considered overcoming adverse prognosis of this aberration. Predictive markers of response to lenalidomide maintenance have remained elusive. We have previously shown that IMiDs exert their anti-MM activity via destabilization of MCT1 and CD147 and combined overexpression reduces response to lenalidomide-treatment in vitro and in an in vivo MM xenograft model (Eichner et al. Nature Medicine 2016). Methods: CD138-purified myeloma cell samples of 654 patients receiving high-dose melphalan therapy and autologous stem cell transplantation and either bortezomib (n=101), thalidomide (n=98) or lenalidomide (n=455) maintenance treatment were assessed by gene expression profiling (GEP) using U133 2.0 plus DNA microarrays, 316 by RNA-sequencing (RNA-seq). Expression of CD147 and MCT1 were assessed and correlated with PFS and OS data. Gene expression based risk scores, including UAMS70-gene, Rs-score and gene expression based proliferation index were assessed alongside routine iFISH-analysis. Survival curves and median time to progression were computed with nonparametric survival estimates for censored data using the Kaplan-Meier method. Difference between the curves were tested using the G-rho Log-rank test. Landmark analysis was performed by defining an alternative start point (landmark) at 12 months. In vitro, CD147 and MCT1 were lentivirally overexpressed in MM1S cells, which were subjected to lenalidomide or bortezomib treatment and proliferation analysis. Xenografted MM-tumors were followed by 18FDG-PET and analyzed by immunohistochemistry. Results: Patients with high gene expression levels of MCT1 showed significantly reduced PFS (31.9 vs. 48.2months in MCT1high vs. MCT1low,P=.03) and OS (75.9 months vs. not reached (NR) months in MCT1high vs. MCT1low; P=.001) in case of lenalidomide maintenance. Likewise, patients with thalidomide maintenance showed reduced PFS (34.8 vs. 43.7 months in MCT1high vs. MCT1low, P=.23) and significantly shorter OS (83.6 months vs. not reached (NR) months in MCT1high vs. MCT1low;P=.03). For bortezomib based maintenance, MCT1 expression had no significant impact on PFS (39.8 months vs. 32.6 months in MCT1high vs. MCT1low) and OS (125.8 months vs. 129.8 months in MCT1high vs. MCT1low). No association with other prognostic factors was found. As still differences between MCT1high vs. MCT1lowexpression myeloma cells might be attributed to undiscerned molecular factors and for functional validation, we lentivirally overexpressed CD147 and MCT1 in human myeloma cell lines. Overexpression of MCT1 significantly reduced cytotoxicity of lenalidomide, while no change was observed in MM cells treated with bortezomib. We subsequently validated our results in vivo. Functional investigations in the mechanism of MCT1 impact on cellular survival are ongoing. Conclusion: Taken together MCT1 expression as potential predictive marker for response to IMiD-based maintenance treatment. Both PFS and OS were significantly reduced in patients with high gene expression levels of MCT1. In vitro and in vivo (xenograft model), MCT1 overexpression reduced sensitivity to lenalidomide unlike bortezomib treatment. Disclosures Salwender: Bristol-Myers Squibb: Honoraria, Other: Travel or accommodations; Janssen Cilag: Honoraria, Other: Travel or accommodations; AbbVie: Honoraria; Celgene: Honoraria, Other: Travel or accommodations; Sanofi: Honoraria, Other: Travel or accommodations; Takeda: Honoraria, Other: Travel or accommodations; Amgen: Honoraria, Other: Travel or accommodations. Bertsch:Sanofi: Other: travel support; Celgene: Other: travel support. Goldschmidt:Chugai: Honoraria, Research Funding; Amgen: Consultancy, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Adaptive Biotechnology: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Molecular Partners: Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Research Funding; Dietmar-Hopp-Stiftung: Research Funding; John-Hopkins University: Research Funding; John-Hopkins University: Research Funding; MSD: Research Funding; Mundipharma: Research Funding; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Weisel:Takeda: Consultancy, Honoraria; GSK: Honoraria; Sanofi: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Juno: Consultancy; Bristol-Myers Squibb: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Adaptive Biotech: Consultancy, Honoraria. Scheid:Celgene: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria; Takeda: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria. Bassermann:Celgene: Consultancy, Research Funding.

Combination of Recombinant Factor VIIa and Fibrinogen Corrects Clot Formation in Primary Immune Thrombocytopenia At Very Low Platelet Counts

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4667-4667
Author(s):  
Ole Halfdan Larsen ◽  
Jesper Stentoft ◽  
Deepti Radia ◽  
J∅rgen Ingerslev ◽  
Benny S∅rensen
Keyword(s):  
Platelet Count ◽  
Board Of Directors ◽  
Research Funding ◽  
Immune Thrombocytopenia ◽  
Recombinant Factor Viia ◽  
Factor Viia ◽  
Advisory Committees ◽  
Platelet Counts ◽  
Primary Immune Thrombocytopenia

Abstract Abstract 4667 Introduction: Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by a low platelet count and an increased risk of bleeding. Hemostatic treatment modalities, bypassing the need for platelet transfusion, would be desirable for control of serious acute bleeds in patients with ITP. This study aimed at (i) performing a thorough characterization of the coagulopathy of ITP, (ii) investigate new ways to obtain acute correction of the coagulopathy performing in vitro experiments with recombinant factor VIIa (rFVIIa, NovoSeven®), fibrinogen (RiaSTAP®), and the combination of rFVIIa and fibrinogen, and finally (iii) investigate the correlation of the hemostatic response to the baseline platelet counts of the ITP patients. We challenged the hypothesis that rFVIIa combined with fibrinogen concentrate can correct whole blood (WB) clot formation in patients suffering from ITP even at very low platelet counts. Methods: Blood from 12 ITP patients and 15 healthy controls was drawn into 3.2% citrate containing corn trypsin inhibitor 18.3μg mL−1 to inhibit artificial contact activation. The WB (mean platelet count 22 × 109L−1 (range 0–42)) was spiked in vitro with buffer (control), fresh donor platelets (+40×109 L−1), rFVIIa (1 or 4μg mL−1), or fibrinogen (1 or 3mg mL−1) as well as the combination of rFVIIa and fibrinogen. Dynamic WB coagulation profiles were recorded by ROTEM® Thromboelastometry using activation with tissue factor (0.03pM) and re-calcification. Parameters of clot initiation (clotting time, CT), clot propagation (maximum velocity, MaxVel) as well as clot termination (maximum clot firmness, MCF) were evaluated. Thrombin generation in “platelet-rich” ITP plasma was evaluated using calibrated automated thrombography. Overall differences between groups were evaluated by paired and unpaired t-tests as appropriate. Simple linear regression analyses were performed using the differences observed after addition of the various interventions (intervention – baseline) as the dependent variable (y) and the platelet count as the independent variable (x). The slope was used to evaluate dependency of the hemostatic response on the platelet count, whereas the intercept was used to evaluate the hemostatic response at very low platelet counts. A p-value less than 0.05 was considered statistically significant. Results: Compared with healthy controls the WB coagulation profiles of the ITP patients were characterized by a prolonged CT (mean: 1490 vs. 941s, p<0.001) as well as a markedly reduced MaxVel (3.4 vs. 9.7mm×100s−1, p<0.001) and MCF (38.2 vs. 49.4mm, p=0.01). Fibrinogen showed no positive hemostatic effect. Recombinant FVIIa reduced the CT (744s, p<0.001) and increased the MaxVel (6.28mm×100s−1, p<0.001) whereas no change was observed in the MCF. Thrombin generation in “platelet-rich” plasma supported the findings in WB. The improvement in CT following addition of rFVIIa was independent of the platelet count (p-values > 0.45) and the intercept showed a significant improvement at very low platelet counts (1μg mL−1: −643s, p<0.001; 4μg mL−1: −811s, p<0.001). In contrast, the increase in MaxVel after addition of rFVIIa was highly dependent on the platelet count (1μg mL−1: R2 = 0.81, p < 0.001; 4μg mL−1: R2 = 0.86, p < 0.001) and the intercept was not significant (1μg mL−1: 0.05mm×100s−1 p=0.87; 4μg mL−1: 0.54 mm×100s−1 p=0.15). The combination of fibrinogen and rFVIIa revealed a synergistic effect also showing an increased MCF (50.7mm) in addition to a reduced CT (794s) and improved MaxVel (7.9 mm×100s−1) displaying larger effects than following fresh donor platelet substitution (CT 1164s; MaxVel 6.96mm×100s−1; MCF 49.6mm). Furthermore, rFVIIa together with fibrinogen also showed a significant response at very low platelet counts in all parameters (Intercept: CT −788s, MaxVel 3.3mm×100s−1, MCF 13.9mm, p-values<0.004) Conclusions: Data suggest that rFVIIa combined with fibrinogen can correct the coagulopathy of ITP even at very low platelet counts, and may be an alternative to platelet transfusion. Clinical trials are needed to further investigate if this new treatment modality holds the potential to serve as an effective acute treatment option in ITP. Disclosures: Off Label Use: Recombinant activated factor VII (NovoSeven) and fibrinogen concentrate (RiaSTAP). In vitro data suggesting a haemostatic effect in primary immune thrombocytopenia will be presented. S∅rensen:Novo Nordisk: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Baxter: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; CSL Behring: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bayer: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; SOBI: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pentapharm: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Grifols: Research Funding; LFB: Research Funding; Octapharma: Research Funding.

scholarly journals Combination Treatment with 5F9 and Azacitidine Enhances Phagocytic Elimination of Acute Myeloid Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2729-2729 ◽  
Author(s):  
Dongdong Feng ◽  
Phung Gip ◽  
Kelly Marie McKenna ◽  
Feifei Zhao ◽  
Ofelia Mata ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Bioluminescence Imaging ◽  
Employment Equity ◽  
Advisory Committees ◽  
Human Macrophages ◽  
Equity Ownership

Abstract CD47 is an anti-phagocytic signal and macrophage checkpoint that acute myeloid leukemia (AML) and other cancer cells utilize to evade innate immunity and establish disease. 5F9 is a humanized IgG4 monoclonal antibody (mAb) that binds to human CD47 and blocks its interaction with its macrophage receptor SIRPα, thereby promoting phagocytosis of cancer cells. We have found in numerous preclinical studies that anti-CD47 Abs synergize with targeted Abs (such as rituximab and cetuximab) by promoting phagocytosis, and also enable antigen cross-presentation and activation of cytotoxic T cells. These preclinical findings are being translated into clinical results as we have established in several clinical trials promising preliminary evidence of 5F9's therapeutic potential. In this study, we hypothesized that combining 5F9 with azacytidine (AZA) would enhance therapeutic efficacy against AML. AZA (Vidaza®) is a hypomethylating and chemotherapeutic agent indicated for AML. AZA's anti-cancer mechanism of action is believed to be twofold, the first being induction of DNA demethylation and the second being its anti-metabolite activity. Interestingly, it has also been found that AZA can increase the expression of the anti-phagocytic signal, CD47, and the pro-phagocytic signal, calreticulin, in myeloid malignancies. Based on these previous findings, we hypothesized that AML cells may be more efficaciously eliminated using a combination of AZA and 5F9 through enhancement of AML cell phagocytosis. We first tested this hypothesis using an in vitro phagocytosis assay. AML cells (i.e. GFP-expressing HL60 cells) were incubated for 24 hours with 3µM AZA and afterwards, the HL60-GFP cells were co-cultured for 2 hours with either human macrophages plus IgG4 control or 5F9 (10µg/ml). Phagocytosis of HL60 AML cells was calculated as a percentage of GFP-positive macrophages (i.e. the amount of macrophages that engulfed GFP-positive HL60 cells), compared to total number of macrophages. Results were normalized to a condition that produced the maximum amount of phagocytosis (100%). We found that the combination of AZA with 5F9 enhanced the human macrophage-mediated phagocytic elimination of HL60-GFP cells compared to either agent alone (Fig. 1). Next, we asked whether we could confirm our in vitro findings in vivo utilizing an aggressive AML xenograft mouse model. HL60-GFP cells (500,000 cells/per mouse) expressing luciferase were engrafted by intravenous injection into 6 - 8 week old immune-deficient NSG (NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ) mice. Three days post engraftment (PE), bioluminescence imaging was performed to assess AML engraftment based on total flux (photons/sec). Animals were randomized based on these values into 6 treatment cohorts with 8 animals per group. Treatment was performed as follows: (1) control (PBS) was initiated on day 4 PE and continued for 14 consecutive daily doses; (2) AZA (7.5 mg/kg) was initiated on day 4 PE and continued for 5 consecutive daily doses; (3) two cohorts of 5F9 (10mg/kg) were initiated at day 4 or day 7 PE and continued for 14 consecutive daily doses; and (4) two combination cohorts of AZA with 5F9 were initiated according to the 5F9 monotherapy dosing regimens. Routine bioluminescence imaging was performed during treatment and for several months after to assess AML burden and reoccurrence. Both combination cohorts inhibited AML growth as early as day 10 PE, and maintained elimination of growth and overall survival up to 255 days PE. In contrast, the AZA and 5F9 monotherapies initiated at day 7 PE (D7), decreased AML growth at day 10 PE, but failed to produce a durable response. Notably, as the AML expanded, all animals from the AZA cohort died by 46 days PE, and all animals from the 5F9 cohort died by 61 days PE. Of the 8 animals from the 5F9 cohort that received treatment on day 4 PE, only two animals demonstrated progressive disease and did not survive. The remaining animals from this cohort had no detectable AML cancer cells (Fig 2). In summary, the combination of 5F9 with AZA significantly enhanced the phagocytic elimination of AML cells by human macrophages in vitro, enhanced clearance of AML in vivo, and prolonged survival compared to single agent treatment with AZA or 5F9. These results support the rationale for investigating a combinatorial treatment of 5F9 and AZA in patients with AML. A clinical trial with this combination in patients with AML is currently ongoing (NCT03248479). Disclosures Feng: Forty Seven Inc: Employment, Equity Ownership. Gip:Forty Seven Inc: Equity Ownership. McKenna:Forty Seven Inc.: Equity Ownership. Zhao:Forty Seven Inc: Consultancy. Mata:Forty Seven Inc: Employment, Equity Ownership. Choi:Forty Seven Inc: Employment, Equity Ownership. Duan:Forty Seven Inc: Employment, Equity Ownership. Sompalli:Forty Seven Inc: Employment, Equity Ownership. Majeti:BioMarin: Consultancy; Forty Seven, Inc: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Weissman:Forty Seven, Inc: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Takimoto:Forty Seven Inc: Employment, Equity Ownership, Patents & Royalties. Chao:Forty Seven Inc: Employment, Equity Ownership, Patents & Royalties. Chen:Forty Seven Inc: Consultancy, Equity Ownership. Liu:Forty Seven Inc: Employment, Equity Ownership, Patents & Royalties. Volkmer:Forty Seven Inc: Employment, Equity Ownership, Patents & Royalties.

scholarly journals Therapy-Related Myeloid Neoplasm Has a Distinct Pro-Inflammatory Bone Marrow Microenvironment and Delayed DNA Damage Repair

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 37-38
Author(s):  
Monika M Kutyna ◽  
Li Yan A Wee ◽  
Sharon Paton ◽  
Dimitrios Cakouros ◽  
Agnieszka Arthur ◽  
...  
Keyword(s):  
Dna Damage ◽  
Board Of Directors ◽  
Research Funding ◽  
High Dose ◽  
Cytotoxic Therapy ◽  
Advisory Committees ◽  
Myeloid Neoplasm ◽  
Myeloid Neoplasms ◽  
Damage Repair

Introduction: Therapy-related myeloid neoplasms (t-MN) are associated with extremely poor clinical outcomes in otherwise long-term cancer survivors. t-MN accounts for ~20% of cases of myeloid neoplasms and is expected to rise due to the increased use of chemotherapy/radiotherapy (CT/RT) and improved cancer survivorship. Historically, t-MN was considered a direct consequence of DNA damage induced in normal hematopoietic stem cells (HSC) by DNA damaging cytotoxics. However, these studies have largely ignored the bone marrow (BM) microenvironment and the effects of age and concurrent/previous cancers. Aim: We performed an exhaustive functional study of mesenchymal stromal cells (MSC) obtained from a comparatively large cohort of t-MN patients and carefully selected control populations to evaluate the long-term damage induced by cytotoxic therapy to BM microenvironment and its impact on malignant and normal haematopoiesis. Methods: Four different cohorts were used: (1) t-MN, in which myeloid malignancy occurred after CT/RT for a previous cancer (n=18); (2) patients with multiple cancer and in which a myeloid neoplasm developed following an independent cancer which was not treated with CT/RT (MC-MN; n=10); (3) primary MN (p-MN; n=7) untreated and without any prior cancer or CT/RT; (4) age-matched controls (HC; n=17). Morphology, proliferation, cellular senescence, differentiation potential and γH2AX DNA damage response was performed. Stem/progenitor supportive capacity was assessed by co-culturing haematopoietic stem cells on MSC feeder-layer in long-term culture initiating assay (LTC-IC). Cytokine measurements were performed using 38-plex magnetic bead panel (Millipore) and RNA sequencing libraries were prepared with Illumina TruSeq Total RNA protocol for 150bp paired-end sequencing on a NextSeq500 instrument. Functional enrichment analysis was performed using EnrichR software. Results: MSC cultured from t-MN patients were significantly different from HC, p-MN and MC-MN MSC according to multiple parameters. They exhibited aberrant morphology consisting of large, rounded and less adhesive cells compared to typical spindle-shaped morphology observed with controls. MSC from myeloid neoplasm also showed impaired proliferation, senescence, osteo- and adipogenic differentiation with t-MN MSC showing the greatest differences. DNA repair was dramatically impaired compared to p-MN and HC (Fig.1A). Importantly, these aberrant t-MN MSC were not able to support normal or autologous in vitro long-term haematopoiesis (Fig.1B). The biological characteristic and poor haematopoietic supportive capacity of MSC could be "cell-intrinsic" or driven by an altered paracrine inflammatory microenvironment. Interestingly, several inflammatory cytokines were higher in t-MN compared with marrow interstitial fluid obtained from p-MN patients (Fig.1Ci) and many of these including Fractalkine, IFNα2, IL-7 and G-CSF were also significantly higher in t-MN MSC conditional media (Fig.1Cii). Together, this data suggest that t-MN microenvironment is distinct from p-MN with paracrine production of pro-inflammatory milieu that may contribute to poor HSC supportive capacity. Preliminary whole transcriptome analysis revealed differential gene expression between t-MN and HC (Fig.1Di) and p-MN MSC. Importantly, the deregulated genes play critical role in cell cycle, DNA damage repair, and cellular senescence pathways explaining phenotypical characteristic of t-MN MSC (Fig.1Dii). Moreover CXCL12 expression, a key regulator of haematopoiesis, was significantly lower in t-MN compared to HC (p=0.002) and p-MN MSC (p=0.009), thus explaining poor HSC supportive capacity. The key difference between the p-MN, MC-MN and t-MN is prior exposure to CT/RT. To study this we obtained MSC from two t-MN patients for whom we had samples at the time of their primary cancer, post high-dose chemotherapy and at the time of t-MN. MSC displayed aberrant proliferation and differentiation capacity after high-dose cytotoxic therapy (2 to 4 years prior to developing t-MN) and remained aberrant at t-MN diagnosis (Fig.1E). Conclusions: BM-MSC from t-MN patients are significantly abnormal compared with age-matched controls and typical myeloid neoplasm. Importantly, prior CT/RT leads to long-term irreversible damage to the BM microenvironment which potentially contributes to t-MN pathogenesis. Disclosures Hughes: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Hiwase:Novartis Australia: Research Funding.

scholarly journals Conventional Immunochemotherapy (R-CHOEP) Vs High-Dose Immunochemotherapy (R-MegaCHOEP) in Younger Patients with High-Risk Aggressive B-Cell Lymphoma: 10-Year Long-Term Follow-up of a German Lymphoma Alliance (GLA) Study

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1589-1589
Author(s):  
Fabian Frontzek ◽  
Marita Ziepert ◽  
Maike Nickelsen ◽  
Bettina Altmann ◽  
Bertram Glass ◽  
...  
Keyword(s):  
High Risk ◽  
Board Of Directors ◽  
Research Funding ◽  
Advisory Board ◽  
High Dose ◽  
Advisory Committees ◽  
Scientific Advisory Board ◽  
Scientific Advisory

Introduction: The R-MegaCHOEP trial showed that dose-escalation of conventional chemotherapy necessitating autologous stem cell transplantation (ASCT) does not confer a survival benefit for younger patients (pts) with high-risk aggressive B-cell lymphoma in the Rituximab era (Schmitz et al., Lancet Oncology 2012; 13, 1250-1259). To describe efficacy and toxicity over time and document the long-term risks of relapse and secondary malignancy we present the 10-year follow-up of this study. Methods: In the randomized, prospective phase 3 trial R-MegaCHOEP younger pts aged 18-60 years with newly diagnosed, high-risk (aaIPI 2-3) aggressive B-cell lymphoma were assigned to 8 cycles of CHOEP (cyclophosphamide, doxorubcine, vincristine, etoposide, prednisone) or 4 cycles of dose-escalated high-dose therapy (HDT) necessitating repetitive ASCT both combined with Rituximab. Both arms were stratified according to aaIPI, bulky disease, and center. Primary endpoint was event-free survival (EFS). All analyses were calculated for the intention-to-treat population. This follow-up report includes molecular data based on immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) for MYC (IHC: 31/92 positive [40-100%], FISH: 14/103 positive), BCL2 (IHC: 65/89 positive [50-100%], FISH: 23/111 positive) and BCL6 (IHC: 52/86 positive [30-100%], FISH: 34/110 positive) and data on cell of origin (COO) classification according to the Lymph2CX assay (GCB: 53/88; ABC: 24/88; unclassified: 11/88). Results: 130 pts had been assigned to R-CHOEP and 132 to R-MegaCHOEP. DLBCL was the most common lymphoma subtype (~80%). 73% of pts scored an aaIPI of 2 and 27% an aaIPI of 3. 60% of pts had an initial lymphoma bulk and in 40% more than 1 extranodal site was involved. After a median observation time of 111 months, EFS at 10 years was 57% (95% CI 47-67%) in the R-CHOEP vs. 51% in the R-MegaCHOEP arm (42-61%) (hazard ratio 1.3, 95% CI 0.9-1.8, p=0.228), overall survival (OS) after 10 years was 72% (63-81%) vs. 66% (57-76%) respectively (p=0.249). With regard to molecular characterization, we were unable to detect a significant benefit for HDT/ASCT in any subgroup analyzed. In total, 16% of pts (30 pts) relapsed after having achieved a complete remission (CR). 23% of all relapses (7 pts) showed an indolent histology (follicular lymphoma grade 1-3a) and 6 of these pts survived long-term. In contrast, of 23 pts (77%) relapsing with aggressive DLBCL or unknown histology 18 pts died due to lymphoma or related therapy. The majority of relapses occurred during the first 3 years after randomization (median time: 22 months) while after 5 years we detected relapses only in 5 pts (3% of all 190 pts prior CR). 11% of pts were initially progressive (28 pts) among whom 71% (20 pts) died rapidly due to lymphoma. Interestingly, the remaining 29% (8 pts) showed a long-term survival after salvage therapy (+/- ASCT); only 1 pt received allogeneic transplantation. The frequency of secondary malignancies was very similar in both treatment arms (9% vs. 8%) despite the very high dose of etoposide (total 4g/m2)in the R-MegaCHOEP arm. We observed 2 cases of AML and 1 case of MDS per arm. In total 70 pts (28%) have died: 30 pts due to lymphoma (12%), 22 pts therapy-related (11 pts due to salvage therapy) (9%), 8 pts of secondary neoplasia (3%), 5 pts due to concomitant disease (2%) and 5 pts for unknown reasons. Conclusions: This 10-year long-term follow-up of the R-MegaCHOEP trial confirms the very encouraging outcome of young high-risk pts following conventional chemotherapy with R-CHOEP. High-dose therapy did not improve outcome in any subgroup analysis including molecular high-risk groups. Relapse rate was generally low. Pts with aggressive relapse showed a very poor long-term outcome while pts with indolent histology at relapse survived long-term. Secondary malignancies occurred; however, they were rare with no excess leukemias/MDS following treatment with very high doses of etoposide and other cytotoxic agents. Supported by Deutsche Krebshilfe. Figure Disclosures Nickelsen: Roche Pharma AG: Membership on an entity's Board of Directors or advisory committees, Other: Travel Grants; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Janssen: Membership on an entity's Board of Directors or advisory committees. Hänel:Amgen: Honoraria; Celgene: Other: advisory board; Novartis: Honoraria; Takeda: Other: advisory board; Roche: Honoraria. Truemper:Nordic Nanovector: Consultancy; Roche: Research Funding; Mundipharma: Research Funding; Janssen Oncology: Consultancy; Takeda: Consultancy, Research Funding; Seattle Genetics, Inc.: Research Funding. Held:Roche: Consultancy, Other: Travel support, Research Funding; Amgen: Research Funding; Acrotech: Research Funding; MSD: Consultancy; Bristol-Myers Squibb: Consultancy, Other: Travel support, Research Funding. Dreyling:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: scientific advisory board, Research Funding, Speakers Bureau; Bayer: Consultancy, Other: scientific advisory board, Speakers Bureau; Celgene: Consultancy, Other: scientific advisory board, Research Funding, Speakers Bureau; Mundipharma: Consultancy, Research Funding; Gilead: Consultancy, Other: scientific advisory board, Speakers Bureau; Novartis: Other: scientific advisory board; Sandoz: Other: scientific advisory board; Janssen: Consultancy, Other: scientific advisory board, Research Funding, Speakers Bureau; Acerta: Other: scientific advisory board. Viardot:Kite/Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria; F. Hoffmann-La Roche Ltd: Honoraria, Membership on an entity's Board of Directors or advisory committees. Rosenwald:MorphoSys: Consultancy. Lenz:Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; AstraZeneca: Consultancy, Honoraria, Research Funding; Agios: Research Funding; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Bayer: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Roche: Employment, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy. Schmitz:Novartis: Honoraria; Gilead: Honoraria; Celgene: Equity Ownership; Riemser: Consultancy, Honoraria.

scholarly journals VTE Rates and Safety Analysis of Newly Diagnosed Multiple Myeloma Patients Receiving Carfilzomib-Lenalidomide-Dexamethasone (KRD) with or without Rivaroxaban Prophylaxis

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1835-1835 ◽  
Author(s):  
Katrina M Piedra ◽  
Hani Hassoun ◽  
Larry W. Buie ◽  
Sean M. Devlin ◽  
Jessica Flynn ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Venous Thromboembolism ◽  
Board Of Directors ◽  
Research Funding ◽  
High Dose ◽  
Newly Diagnosed ◽  
Advisory Committees ◽  
Cancer Trial ◽  
Oncology Research ◽  
Increased Risk

Introduction Immunomodulatory agents (IMiD's) are associated with an increased risk of venous thromboembolism (VTE), particularly when combined with high dose steroids. Studies evaluating the use of lenalidomide-bortezomib-dexamethasone (RVD) and carfilzomib-lenalidomide-dexamethasone (KRD) in the frontline setting for multiple myeloma (MM) have reported a 6% and 24% incidence of thrombosis, respectively, despite primary thrombotic prophylaxis with aspirin (ASA) (Richardson, et al. Blood. 2010; Korde, et al. JAMA Oncol 2015). Recent data, including the Hokusai VTE Cancer Trial, have suggested that safety and efficacy of direct oral anticoagulants (DOACs) are preserved in the setting of treatment of solid malignancy-associated thrombosis (Raskob, et al. N Engl J Med. 2018; Mantha, et al. J Thromb Thrombolysis. 2017). Despite this data, there is limited experience and use of DOACs in prevention of thromboses in the setting of hematologic malignancies, specifically MM. After careful review of literature, since early 2018, we changed our clinical practice and routinely placed newly diagnosed MM (NDMM) patients receiving KRD at Memorial Sloan Kettering Cancer Center (MSKCC) on concomitant rivaroxaban 10 mg once daily, regardless of VTE risk stratification. In the following abstract, we present VTE rates and safety data for newly diagnosed MM patients receiving RVD with ASA vs. KRD with ASA vs. KRD with rivaroxaban prophylaxis. Methods This was an IRB-approved, single-center, retrospective chart review study. All untreated patients with newly diagnosed MM, receiving at least one cycle of RVD or KRD between January 2015 and October 2018 were included. The period of observation included the time between the first day of therapy until 90 days after completion of induction therapy. Patients were identified by querying the pharmacy database for carfilzomib or bortezomib administration and outpatient medication review of thromboprophylaxis with rivaroxaban or ASA. VTE diagnoses were confirmed by ICD-10 codes and appropriate imaging studies (computed tomography and ultrasound). Descriptive statistics were performed. Results During the observation period, 241 patients were identified to have received RVD or KRD in the frontline (99 RVD with ASA; 97 KRD with ASA; 45 KRD with rivaroxaban). Baseline characteristics were well distributed among the three arms, with a median age of 60 (30-94) in the RVD ASA arm, 62 (33-77) in the KRD ASA arm, and 60 (24-79) in the KRD rivaroxaban arm. Patients had International Staging System (ISS) stage 3 disease in 13% (N=13), 9.3% (N=9), and 11% (N=5) of the RVD ASA, KRD ASA, and KRD rivaroxaban arms, respectively. Median weekly doses of dexamethasone were higher in both KRD arms, 40 mg (20-40) vs. 20 mg (10-40) in the RVD ASA arm. The average initial doses of lenalidomide were 22 mg in the RVD ASA arm compared to 25 mg in both the KRD ASA and KRD rivaroxaban arms. After querying the pharmacy database, no patients were identified to have a history or concomitant use of erythropoietin stimulating agent (ESA) use. Treatment-related VTE's occurred in 4 patients (4.0%) in the RVD ASA arm, 16 patients (16.5%) in the KRD ASA arm, and in 1 patient (2.2%) in the KRD rivaroxaban arm. Average time to VTE was 6.15 months (Range 5.42, 9.73) after treatment initiation in the RVD ASA group, while it was 2.61 months (Range 0.43, 5.06) in the KRD ASA group and 1.35 months in the KRD rivaroxaban group. Minor, grade 1 bleeding events per the Common Terminology Criteria for Adverse Events (CTCAE) were identified in 1 (1.1%) patient in the RVD ASA arm, 5 (5.2%) patients in the KRD ASA arm, and 1 (2.2%) patient in the KRD rivaroxaban arm. Conclusion More efficacious MM combination therapies have been found to increase the risk of VTE when using ASA prophylaxis, indicating better thromboprophylaxis is needed. We found patients receiving ASA prophylaxis with KRD were more likely to experience a VTE and these events occurred earlier compared to patients receiving ASA prophylaxis with RVD. Importantly, the rate of VTE was reduced to the same level as ASA prophylaxis with RVD when low-dose rivaroxaban 10 mg daily was used with KRD, and without necessarily increasing bleeding risk. Our retrospective data support the development of prospective clinical trials further investigating DOAC use in thromboprophylaxis for NDMM patients receiving carfilzomib-based treatments. Figure Disclosures Hassoun: Novartis: Consultancy; Janssen: Research Funding; Celgene: Research Funding. Lesokhin:BMS: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria; Janssen: Research Funding; GenMab: Consultancy, Honoraria; Serametrix Inc.: Patents & Royalties; Genentech: Research Funding; Juno: Consultancy, Honoraria. Mailankody:Juno: Research Funding; Celgene: Research Funding; Janssen: Research Funding; Takeda Oncology: Research Funding; CME activity by Physician Education Resource: Honoraria. Smith:Celgene: Consultancy, Patents & Royalties, Research Funding; Fate Therapeutics and Precision Biosciences: Consultancy. Landgren:Theradex: Other: IDMC; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Other: IDMC; Sanofi: Membership on an entity's Board of Directors or advisory committees; Adaptive: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. OffLabel Disclosure: Off-label use of rivaroxaban for outpatient prophylaxis of venous thromboembolism (VTE) will be explicitly disclosed to the audience.

scholarly journals TTI-281, an Orally Bioavailable Bromodomain and Extraterminal Domain (BET) Inhibitor, Is a Promising Candidate for the Treatment of Multiple Myeloma

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2095-2095
Author(s):  
Zezhou Wang ◽  
Jaehyun Choi ◽  
Peter Dove ◽  
Chunlei Wang ◽  
Aaron D. Schimmer ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Board Of Directors ◽  
Therapeutic Agents ◽  
Vehicle Control ◽  
Advisory Committees ◽  
Bet Inhibitor ◽  
Low Toxicity ◽  
Orally Bioavailable

Abstract Although recent advances in the development of multiple myeloma (MM) therapies such as proteasome inhibitors and immunomodulatory agents have improved patient outcomes, MM remains incurable. Additional therapeutic agents with high efficacy, low toxicity and the convenience of oral administration are in high demand. BET inhibitors, such as JQ-1, have been considered as potential therapeutic agents for MM. In the present study, we report that TTI-281, an orally bioavailable BET inhibitor, displays anti-MM activity with a low toxicity profile in preclinical studies. First, TTI-281 was tested for binding and anti-tumor activity in vitro. BROMOscan and AlphaScreen assays demonstrated that TTI-281 bound to bromodomains of BRD2/BRD3/BRD4 with Kd values less than 10 nM. In MTS assays, TTI-281 inhibited the growth of MM cell lines (MM.1s, NCIH929, and RPMI-8826) with cell growth-inhibition (IC50) values less than 300 nM. Next, in vitro ADME screening and in vivo PK studies were conducted. Permeability assays using murine gastrointestinal epithelial cells indicated that TTI-281 had good permeability with little efflux liability (efflux ratio <1), suggesting favorable properties for oral absorption. Indeed, TTI-281 displayed excellent oral bioavailability in both mice and rats (93.1% and 91.8%, respectively). In addition, TTI-281 did not interfere with the metabolism of representative CYP isozyme substrates at concentrations up to 50 μM in pooled human liver microsomes. Data also suggested minimal potential for drug-drug interactions, allowing for the possible combination with first-line therapy to improve therapeutic and survival outcomes. Finally, TTI-281 was tested for anti-myeloma efficacy and tolerability in vivo. NOD-SCID mice (n=10/group) subcutaneously engrafted with the human myeloma cell line MM.1S were treated orally once daily for 21 days with different doses of TTI-281, vehicle control or the benchmark drug carfilzomib. TTI-281 reduced tumor growth in a dose-dependent manner in this MM xenograft model. At 30 mg/kg/day, TTI-281 led to a statistically significant decrease in tumor growth compared with the vehicle control and carfilzomib (reduced tumor volume: 67% after TTI-281 treatment vs 33% after carfilzomib treatment, p<0.0003). Furthermore, TTI-281 treatment was well tolerated, with no effect on body weight or other obvious toxicity. In summary, our preclinical data suggest that the orally available BET inhibitor TTI-281 has an excellent efficacy and safety profile, highlighting its potential as a promising drug candidate for myeloma therapy. Disclosures Wang: Trillium Therapeutics: Employment, Patents & Royalties. Choi:Trillium Therapeutics: Employment. Dove:Trillium Therapeutics: Employment, Patents & Royalties. Wang:Trillium Therapeutics: Employment. Schimmer:Novartis: Honoraria. Petrova:Trillium Therapeutics Inc: Employment, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Uger:Trillium Therapeutics: Employment, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Slassi:Trillium Therapeutics: Employment, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

A Pilot Study of Acalabrutinib with Bendamustine/Rituximab Followed By Cytarabine/Rituximab (R-ABC) for Untreated Mantle Cell Lymphoma

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 8-9
Author(s):  
Daniel Guy ◽  
Marcus Watkins ◽  
Fei Wan ◽  
Nancy L. Bartlett ◽  
Amanda F Cashen ◽  
...  
Keyword(s):  
Stem Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Residual Disease ◽  
Complete Response ◽  
High Dose ◽  
Advisory Committees ◽  
Mantle Cell ◽  
Grade 3 ◽  
Stem Cell Collection

Introduction The management of younger fit patients with mantle cell lymphoma (MCL) varies widely with no consensus on an optimal induction therapy. To date, the treatments with the longest progression-free survival incorporate a chemotherapy backbone that includes high dose cytarabine, followed by consolidation with an autologous stem-cell transplantation (ASCT) (Hermine et al. Lancet 2016, Eskelund et al. Br J Haematol 2016). Recent data showed that a regimen of bendamustine/rituximab followed by cytarabine/rituximab achieved high complete response rates with high minimal residual disease (MRD) negativity (Merryman RW et al. Blood Adv 2020). We hypothesized that adding the Bruton tyrosine kinase inhibitor acalabrutinib to the same chemotherapeutic backbone would be safe and increase complete response rates as well as minimal residual disease (MRD) negativity pre-transplant, and potentially improve clinical outcomes. Methods We conducted a single arm, single institution pilot study registered at clinicaltrials.gov (NCT03623373). Patients with untreated MCL, who were between ages 18-70 and were candidates for ASCT, were eligible. Patients received six 28-day cycles of treatment. Cycles 1-3 consisted of bendamustine 90 mg/m2 on days 1 and 2, rituximab 375 mg/m2 on day 1 and acalabrutinib 100mg BID on days 1 through 28. Cycles 4-6 consisted of rituximab 375 mg/m2 on day 1, cytarabine 2 g/m2 (1.5 g/m2 if age&gt;60) q12 hours on days 1 and 2, and acalabrutinib 100mg BID on days 1 through 7 and 22 through 28. Restaging PET/CT and response assessment based on the Lugano classification were obtained following cycles 3 and 6. After cycle 6 patients underwent leukapheresis and stem-cell collection as preparation for ASCT. Blood for MRD status was collected after cycles 2, 4 and 6 and will be evaluated using the ClonoSeq assay (Adaptive Biotechnologies). The primary objective was to determine the stem cell mobilization success rate. Secondary objectives included safety and tolerability, overall response rate (ORR), pre-transplant complete response rate (CR), and the MRD negativity rate during and after completion of therapy. Results The trial enrolled 14 patients from December 2018 to February 2020. One patient withdrew consent prior to start of treatment and another was found to have an undiagnosed adenocarcinoma shortly after starting MCL treatment. Both are excluded from the analysis. The median age was 57 years (range 52-66). 11 patients were males (92%), all patients had an ECOG performance status of 0-1. 11 patients (92%) presented with stage IV disease. The mean MCL International Prognostic Index (MIPI) score was 6.3 (25% high-risk, 42% intermediate-risk and 33% low-risk). Of the 12 patients who began treatment, 9 completed all 6 cycles. Three patients did not complete therapy due to: insurance issues (n = 1), and thrombocytopenia (n = 2) following cycle 5 and 4. The side effect profile showed expected hematologic toxicities with grade 3-4 cytopenias in all patients, mostly during cytarabine cycles. In total, 100% of patients developed grade 3-4 thrombocytopenia and 83% of patients developed grade 3-4 neutropenia. Three episodes of febrile neutropenia were observed. One patient had a grade 3 transaminase increase, and one patient had grade 3 diarrhea. No bleeding events or treatment related deaths occurred. The remainder of the side effects were low grade and the treatment was generally well tolerated. Of the 12 evaluable patients, 10 responded (ORR 83%) with 9 achieving CR (75%). One patient achieved PR prior to being removed from the study due to thrombocytopenia and then achieved CR off study. Two patients experienced PD during induction. With a median follow up of 9 months, no responding patients have relapsed. The median CD34+ stem cell collection was 3.84x106 cells/kg (range 2.77 - 5.9). MRD results will be presented at the meeting. Conclusions This is the first study attempting to combine BTK inhibition with a high dose cytarabine containing regimen. The addition of acalabrutinib to a regimen of bendamustine/rituximab followed by cytarabine/rituximab appears to be safe. The R-ABC combination will be further tested in the recently activated intergroup trial EA4181. Disclosures Bartlett: Autolus: Research Funding; BMS/Celgene: Research Funding; Forty Seven: Research Funding; Immune Design: Research Funding; Janssen: Research Funding; Kite, a Gilead Company: Research Funding; Merck: Research Funding; Millennium: Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Consultancy, Research Funding; Roche/Genentech: Consultancy, Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; BTG: Consultancy; Acerta: Consultancy; Affimed Therapeutics: Research Funding; ADC Therapeutics: Consultancy. Fehniger:ImmunityBio: Research Funding; HCW Biologics: Research Funding; Kiadis: Consultancy; Nkarta: Consultancy; Indapta: Consultancy; Wugen: Consultancy; Orca Biosystems: Consultancy; Compass Therapeutics: Research Funding. Ghobadi:Amgen: Consultancy, Research Funding; Kite: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy; EUSA: Consultancy; WuGen: Consultancy. Mehta-Shah:Bristol Myers-Squibb: Research Funding; C4 Therapeutics: Consultancy; Celgene: Research Funding; Genetech/Roche: Research Funding; Innate Pharmaceuticals: Research Funding; Kyowa Hakko Kirin: Consultancy; Verastem: Research Funding; Karyopharm Therapeutics: Consultancy; Corvus: Research Funding. Kahl:Celgene Corporation: Consultancy; AstraZeneca Pharmaceuticals LP: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy; Pharmacyclics LLC: Consultancy; Roche Laboratories Inc: Consultancy; BeiGene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Acerta: Consultancy, Research Funding; ADC Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy.

Response and Outcomes to Nilotinib at 24 Months in Imatinib-Resistant Chronic Myeloid Leukemia Patients in Chronic Phase (CML-CP) and Accelerated Phase (CML-AP) with and without BCR-ABL Mutations.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1130-1130 ◽  
Author(s):  
Jerald P. Radich ◽  
Giovanni Martinelli ◽  
Andreas Hochhaus ◽  
Enrico Gottardi ◽  
Simona Soverini ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Median Time ◽  
Research Funding ◽  
Philadelphia Chromosome ◽  
Chronic Phase ◽  
Cytogenetic Response ◽  
Molecular Response ◽  
Advisory Committees ◽  
Imatinib Resistant

Abstract Abstract 1130 Poster Board I-152 Background Nilotinib is a selective and potent BCR-ABL inhibitor, with in vitro activity against most BCR-ABL mutants (excluding T315I) indicated for the treatment of patients with Philadelphia chromosome positive (Ph+) CML in CPor AP resistant or -intolerant to prior therapy, including imatinib. In a previous analysis of nilotinib in patients with BCR-ABL mutations, mutations occurring at three specific amino acid residues (E255K/V, Y253H, and F359C/V) were shown to be associated with less favorable response to nilotinib. The current analysis is based on mature data with a minimum follow-up of 24-months for all patients. Outcomes of patients at 24 months were analyzed by mutation type. Methods Imatinib-resistant CML-CP (n = 200) and CML-AP (n = 93) patients were subdivided into the following mutational subsets: no mutation, sensitive mutations (including mutations with unknown in vitro IC50). or E255K/V, Y253H, or F359C/V mutations at baseline. Patients with mutations of unknown in vitro sensitivity were classified as sensitive in this analysis based on a previous finding that patients with these mutations responded similarly to nilotinib as patients with sensitive mutation. Patients with baseline T315I mutations were excluded from this analysis. Patient groups were analyzed for kinetics and durability of cytogenetic and molecular response to nilotinib, as well as event-free survival (EFS), defined as loss of hematologic or cytogenetic response, progression to AP/BC, discontinuation due to disease progression, or death, and overall survival (OS). Results In CML-CP and -AP patients with no mutation, sensitive mutations, or E255K/V, Y253H, or F359C/V mutations, hematologic, cytogenetic and molecular responses are provided in the Table. Overall, patients with no mutations responded similarly to patients with sensitive mutations, whereas patients with E255K/V, Y253H, or F359C/V mutations had less favorable responses. This correlation was observed in both CML-CP and CML-AP patients, respectively. Median time to CCyR was 3.3 months (range, 1.0–26.7) for CML-CP patients with no mutations, and 5.6 months (range, 0.9–22.1) for patients with sensitive mutations. At 24 months, CCyR was maintained in 74% of CML-CP patients with no mutation and in 84% of patients with sensitive mutations. One patient with CML-CP and an E255K mutation achieved CCyR at 25 months and maintained until last assessment at 30 months. Median time to MMR was similar at 5.6 months (range, 0.9–25.8) for CML-CP patients with no mutations and 5.6 months (range, 2.7–22.1) for patients with sensitive mutations. No patient with a less sensitive mutation achieved MMR. Median EFS and 24-month estimated OS rate are provided in the Table. Conclusions Imatinib-resistant CML-CP and CML-AP patients treated with nilotinib therapy with BCR-ABL mutations (excluding E255K/V, Y253H, or F359C/V) achieved rapid and durable cytogenetic responses, and estimated EFS and OS at 24 months similar to that of patients with no mutations, respectively. Patients with E255K/V, Y253H, or F359C/V mutations had lower and less-durable responses and shorter EFS than patients with sensitive mutations. Alternative therapies may be considered for patients with these uncommon mutations (E255K/V, Y253H, and F359C/V). Disclosures Radich: Novartis: Consultancy, Honoraria, Research Funding. Hochhaus:Novartis: Research Funding. Branford:Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding. Shou:Novartis: Employment. Haque:Novartis: Employment. Woodman:Novartis: Employment. Kantarjian:Novartis: Research Funding. Hughes:Bristol-Myers Squibb: Advisor, Honoraria, Research Funding; Novartis: Advisor, Honoraria, Research Funding. Kim:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Wyeth: Research Funding. Saglio:Novartis: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau.

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