Inecalcitol, a Novel Adjuvant Therapy Inhibiting Chronic Myeloid Leukemia (CML) Stem Cells, Activates a Macrophage Differentiation Pathway in Leukemic Progenitors

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4020-4020
Author(s):  
Christophe Desterke ◽  
Hyacinthe Johnson-Ansa ◽  
Patricia Hugues ◽  
Jean Francois Dufour-Lamartinie ◽  
Remi Delansorne ◽  
...  
Keyword(s):  
Stem Cells ◽  
Chronic Myeloid Leukemia ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
P Value ◽  
Employment Equity ◽  
Macrophage Differentiation ◽  
Advisory Committees ◽  
Cd34 Cells ◽  
Equity Ownership

Abstract Despite the major success obtained with their use in chronic myeloid leukemia (CML), recent data obtained from treatment discontinuation trials suggest that tyrosine kinase inhibitors (TKI) alone are not sufficient to eradicate the most primitive CML stem cells in the majority of the patients. The mechanisms of this inefficiency might involve cell autonomous (activation of alternate signaling, reduced BCR-ABL expression) or non-cell autonomous (niche-related) pathways. Several strategies of targeting the primitive stem cell compartment, in association with TKI, are currently being studied. Inecalcitol (ICC) is a vitamin D3 analog exerting antiproliferative effects in several types of cancer cells. ICC was tested in CD34+ cells isolated from CML patients at diagnosis (n=18) in clonogenic assays as well as in the more primitive LTC-IC-derived progenitors. ICC alone inhibits the clonogenic growth in the majority of the CML patients at diagnosis (15/18 patients). The combination of ICC with either, Imatinib (IM), Dasatinib (DA) or Nilotinib (NIL) in clonogenic assays showed a synergistic effect for the inhibition of CFC growth (10-25% CFC survival) with no toxicity on normal progenitors. Synergistic effects of ICC and TKI was also demonstrated in LTC-IC-derived progenitors with IM, NIL and DA. To determine possible mechanism of action of ICC in CML stem cells, we have performed a gene profiling analysis of CD34+ cells obtained at diagnosis from 4 CML patients. CD34+ cells were cultured for 7 days in the presence of growth factors with or without ICC. In phenotypic analyses, CD34+ cells treated in the presence of ICC showed an increase of monocyte/macrophage differentiation features with increased expression of CD13/CD14 as well as CD11b expression. Day 0 and Day7 RNA with or without ICC treatment were then studied by transcriptome hybridation on human-v2 (8*60k) Agilent technologies microarrays. Data were treated with Feature Extraction 11.5.11, Genespring GX12, Mev 4.9, R software and GSEA 2.2.20. Gene set enrichment analysis performed at day 7 of culture between ICC condition and control untreated cells showed an increase of cell differentiation markers under ICC (Normalized enrichment score = +1.94, p-value < 0.001) One way ANNOVA with False Discovery Rate (FDR) correction allowed to discover 7176 modulated probes between the 3 experimental conditions (Day 0, Day7 without ICC, Day 7 with ICC). CYP24A1 was the gene with the greatest induction by the treatment (Fold Change = +150). CYP24A1 is responsible of the degradation of 1.25(OH)2D3 by the monocyte/macrophage cells. Unsupervised classification with 372 macrophage connected genes (ANOVA p<0.01, FDR with 1000 permutations) allowed to separate samples by their experimental classes. This macrophage expression profile allows to discriminate samples from Day7 control to those of treated cells at the same time on hierarchical classification. This was confirmed by first factorial map of principal component analysis which explained 72% (PCA1 axis) hematopoietic differentiation during 7 days and 10% (PCA2 axis) effect of the treatment at the end of the differentiation. 23 macrophagic genes were indeed found to be specifically induced by the treatment with a fold change greater than 2 as compared to the untreated control: 11 of them participate to integrin-interleukins-chemokines signalizations pathways (p-value adjust FDR = 4.04e-10). Some macrophagic ligands and receptors are over-expressed in CML cells treated with ICC, including CSF2, OSM, TNFSF11, CXCL12 as well as FAS and CXCR2. In summary, these results suggest that one of the major mechanisms of action of ICC in the leukemic progenitors involve differentiation and activation of macrophagic expression profile. This profile could be used to design further therapeutic actions and to predict response to ICC, which is now tested in combination with IM in a clinical trial in France. Disclosures Dufour-Lamartinie: Hybrigenics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Delansorne:Hybrigenics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Turhan:Bristol Myers Squibb: Consultancy; Novartis: Research Funding.

Vitamin D3 Analog Inecalcitol Synergizes Vith Imatinib To Inhibit Selectively The Growth Of Chronic Myeloid Leukemia (CML) Progenitors and Stem Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3981-3981
Author(s):  
Ali G Turhan ◽  
Marie Laure Bonnet ◽  
Bouneau Clementine ◽  
Remi Delansorne ◽  
Jean-François Dufour-Lamartinie ◽  
...  
Keyword(s):  
Stem Cells ◽  
Synergistic Effect ◽  
Board Of Directors ◽  
Vitamin D3 ◽  
Myeloid Leukemia ◽  
Employment Equity ◽  
Advisory Committees ◽  
Cd34 Cells ◽  
Equity Ownership

Abstract Tyrosine kinase inhibitor (TKI) therapies which are the first line drugs in chronic myeloid leukemia (CML) have profoundly changed the prognosis of the disease and prolonged survival. However, it is clear that TKI are not able to eradicate efficiently the most primitive leukemic cells, due to their quiescence or oncogene-independence. It would therefore be of major interest to determine if compounds targeting CML progenitors / stem cells can be used in combination with TKI. Inecalcitol (19, nor 14 epi 23-yne-1,25 (OH)2D3) (ICC) is a vitamin D3 analog which has been shown to exert antiproliferative effects in several types of experimental tumors. As compared to calcitriol, the active for of natural vitamin D3, ICC has been shown to induce less hypercalcemia in vivo in mice and a higher differentiation inducing effect. The effects of ICC in primary CML progenitors and stem cells has not been tested so far. We first studied the effects of ICC on the U937 cell line as this cell line is a model responsive to the differentiation-inducing effects of vitamin D3. We have previously generated U937 cell lines expressing BCR–ABL (Ahmed et al, Leukemia Lymphoma, 2001). The effects of ICC were tested in these cells at day +2, +4 and +7 of culture using ICC at the dose of 5 nM and by the assessment of differentiation based on the morphology and the appearance CD11b and CD14 markers in flow cytometry. In dose-response experiments, we have cultured U937 cells in the presence of 1, 2 and 5 nM of ICC and we have established that the concentration of 5 nM was the most efficient in terms of differentiation induction. In cell kinetics experiments, culture of U937Neo cells as compared to U937-BCR-ABL cells, ICC alone ( 5nM) induced a similar differentiation effect with 45% of control cells and 30% of BCR-ABL cells expression CD11b at day 2, respectively and 30 % of both expressing CD11b at day 5. ICC induced the expression of CD14 at day 2 and day 4 with similar efficiencies, suggesting that BCR-ABL did not interfere with the differentiation inducing effect of ICC. In parallel with the differentiation effect, the cell mortality increased as compared to non-treated cells by 15% at day 5. To determine the effects of ICC in CML progenitors, we have used ICC alone at 1 nM and 5 nM final concentrations and established that the latter had the most inhibitory effect on CD34+ derived colony-forming-cell (CFC) growth (25% and 50% reduction as compared to untreated control n= 2 exp). In further experiments, CD34+ cells isolated from CML patients at diagnosis (n= 5) were tested in clonogenic assays (500 CD34+ cells / dish in triplicates) using a combination of ICC (5 nM) and Imatinib Mesylate (IM) which was used either at a concentration of 0.2 or 0.5 mM. In all CML samples (n= 5) there was a synergistic effect of the combination of IM and ICC, either at IM 0.2 mM and ICC 5nM ( 17% CFC survival n= 2) or IM 0.5 mM and ICC 5nM concentrations (10% CFC survival, n=3). On the other hand, this combination did not inhibit clonogenic cell growth from normal control CD34+ cells tested in the same conditions either with ICC alone at 5 nM ( 111% mean CFC survival as compared to untreated controls n= 3) or in combination of ICC 5 nM and IM 0.5 mM ( 100 % CFC survival n= 3). We have then used CD34+ cells from CML (n=2) and control ( n= 2) CD34+ cells to test the effects of ICC and IM in long-term culture initiating cell (LTC-IC) assays. Long-term cultures were started using 4.104 cells on MS5 cell stroma in three conditions by adding IM 0.5 mM, ICC 5nM or the combination of both in cultures, with weekly half-medium changes during which drugs were added to cultures in replaced medium. At week+5 cultures were terminated and LTC-IC progeny was evaluated. The numbers of non-adherent cells collected from long-term cultures were reduced significantly in the presence of IM and ICC in CML samples. A similar pattern of inhibition was also observed in control CD34+ cultures but in terms of clonogenic activity at week 5, there was a slightly higher inhibition of LTC-IC-derived CFC numbers (n=2) in CML. Thus, these results establish that ICC, a clinically used derivative of vitamin D3 has a clear activity in CML progenitors by itself and a major synergistic effect with Imatinib. The combination is not toxic to normal progenitors. This would suggest that ICC could be used in clinical setting, especially if in future experiments, a synergistic effect could be observed with more potent second generation TKI such as Nilotinib and Dasatinib. Disclosures: Turhan: Bristol Myers Squibb, Novartis: Consultancy, Honoraria. Delansorne:Hybrigenics: Employment, Equity Ownership. Dufour-Lamartinie:Hybrigenics: Employment, Equity Ownership. Guerci-Bresler:Novartis : Honoraria, Membership on an entity’s Board of Directors or advisory committees; Bristol Myers Squibb: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity’s Board of Directors or advisory committees; AMGEN: Honoraria.

Mobilization with Plerixafor (Mozobil ®)Plus G-CSF Results in Superior Day 1 Collection of CD34+ Cells Compared to Placebo Plus G-CSF: Results From Two Randomized Placebo-Controlled Trials in Patients with Multiple Myeloma or Non-Hodgkin's Lymphoma.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3224-3224 ◽  
Author(s):  
Brian J. Bolwell ◽  
Auayporn P. Nademanee ◽  
Patrick Stiff ◽  
Edward Stadtmauer ◽  
Richard T. Maziarz ◽  
...  
Keyword(s):  
Placebo Group ◽  
Board Of Directors ◽  
Research Funding ◽  
Cell Yield ◽  
P Value ◽  
Employment Equity ◽  
Advisory Committees ◽  
Cell Dose ◽  
Cd34 Cells ◽  
Equity Ownership

Abstract Abstract 3224 Poster Board III-161 Background While most centers use 2 × 106 CD34+ cells/kg as the minimal cell dose for autologous hematopoietic stem cell (HSC) transplantation (auto-HSCT), infusion of higher CD34+ cell dose is associated with better outcomes in patients with multiple myeloma (MM) or non-Hodgkin's lymphoma (NHL). Recent evidence suggests a correlation between CD34+ cell yield on Day 1 of collection and total CD34+ cell yield as well as post-transplant outcomes. This analysis was designed to: 1) compare Day 1 collection between patients with NHL or MM mobilized with plerixafor plus G-CSF or placebo plus G-CSF; and 2) determine whether Day 1 CD34+ cell yields correlated with the total mobilization yield and number of apheresis days. Methods Data were obtained from two prospective, randomized, double-blind, placebo-controlled, phase 3 clinical trials that compared the safety and efficacy of plerixafor (0.24 mg/kg/day SQ) plus G-CSF (10 μg/kg/day) with placebo plus G-CSF for mobilization of HSC for auto-HSCT in patients with NHL (3101 Study) or MM (3102 Study). Pearson correlation coefficient was used to evaluate the association of day 1 CD34+ cell collection with total CD34+ cell yield and the number of days of apheresis. Results In the NHL trial, 150 patients were mobilized with plerixafor plus G-CSF and 148 patients underwent mobilization with placebo plus G-CSF. More than half the patients (55.3%) in the plerixafor group collected ≥2 × 106 CD34+ cells/kg on Day 1 of apheresis (Figure 1A). In contrast, 19.6% patients in the placebo group collected ≥ 2 × 106 CD34+ cells/kg on Day 1 of apheresis (p< 0.001). In the MM study, 148 patients were mobilized with plerixafor plus G-CSF and 154 patients were mobilized with placebo plus G-CSF. More than half the patients (52.7%) in the plerixafor group collected ≥6 × 106 CD34+ cells/kg on the first day of collection compared to only 16.9% patients in the placebo group (p<0.001; Figure 1B). There was a strong positive correlation between day 1 collection and the total CD34+ cell yield in patients with NHL (r= 0.86, p-value= <0.0001) or MM (r= 0.87, p-value= <0.0001) in both the plerixafor and placebo groups. For NHL patients, the median Day 1 collection was higher in the plerixafor group compared to the placebo group: 2.66 × 106 vs. 0.77 × 106 CD34+ cells/kg (p<0.001) and this translated into higher total CD34+ cell yields in the two groups respectively: 5.69 × 106 vs. 1.98 × 106 CD34+ cells/kg (p<0.001). Similarly, for MM patients, the median CD34+ cells/kg collected on Day 1 was higher in the plerixafor group compared to the placebo group: 7.01 × 106 vs. 2.29 × 106 CD34+ cells/kg (p<0.001) and this translated into better overall collection in the plerixafor vs. placebo groups: 10.96 × 106 vs. 6.18 × 106 CD34+ cells/kg (p<0.001). A negative correlation was observed between CD34+ cells collected on Day 1 and the number of days of apheresis performed in patients with NHL (r= -0.67, p-value=<0.0001) or MM (r= -0.50, p-value= <0.0001) in both the plerixafor and placebo groups. Consequently, better Day 1 collection in plerixafor-treated NHL or MM patients translated into significantly fewer apheresis days to achieve the target collection compared to placebo treated patients. Conclusions These data support previous reports demonstrating a strong correlation between day 1 CD34+ cell collection and total CD34+ cell yield and apheresis days. These data also demonstrate that addition of plerixafor to G-CSF allows significantly more patients to achieve the target cell collection within 1 day of apheresis compared to G-CSF alone. These findings support the observation that mobilization with plerixafor plus G-CSF reduces the number of apheresis days required to achieve the minimal or optimal cell dose to proceed to transplantation. Disclosures Bolwell: Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Nademanee:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Stiff:Genzyme Corp.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Stadtmauer:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Maziarz:Genzyme Corp.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Micallef:Genzyme Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Marulkar:Genzyme Corporation: Employment, Equity Ownership. Gandhi:Genzyme Corporation: Employment, Equity Ownership. DiPersio:Genzyme: Honoraria.

scholarly journals Comparative Efficacy Among 3rd Line Post-Imatinib Chronic Phase-Chronic Myeloid Leukemia (CP-CML) Patients after Failure of Dasatinib or Nilotinib Tyrosine Kinase Inhibitors

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4551-4551 ◽  
Author(s):  
Jeffrey H. Lipton ◽  
Dhvani Shah ◽  
Vanita Tongbram ◽  
Manpreet K Sidhu ◽  
Hui Huang ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Kinase Inhibitors ◽  
Cytogenetic Response ◽  
Comparative Efficacy ◽  
Employment Equity ◽  
Advisory Committees ◽  
Equity Ownership

Abstract INTRODUCTION Patients with chronic myeloid leukemia (CP-CML) failing 1st line imatinib are most commonly treated with the second-generation (2G) tyrosine kinase inhibitors (TKIs) dasatinib and nilotinib. However, for patients who experience resistance or intolerance (R/I) to 2G-TKIs in 2nd line, there currently is no consensus on the optimal therapy sequence for 3rd line treatment. The comparative efficacy of using ponatinib in the 3rd line after 2G TKI failure was examined in a previous study (Lipton et al., ASH 2013). This study assesses the comparative efficacy of ponatinib versus sequential treatment of alternate 2G TKIs in 3rdline setting in two separate patient populations, post-imatinib and dasatinib patients and post-imatinib and nilotinib patients. METHODS A systematic review was conducted in MEDLINE, EMBASE and the Cochrane Libraries (2002-2014), as well as 3 conferences (ASH (2008-2014), ASCO (2008-2014), and EHA (2008-2013)). Studies evaluating any TKI were included if they enrolled 10 or more post-imatinib adult patients with CP-CML who were also R/I to dasatinib or nilotinib. All study designs were considered and no restriction was applied with respect to therapy dose, due to incomplete reporting of doses in the available studies. Analyses was run on two groups of patients, those failing imatinib and dasatinib (Group Ima/Das) and those failing imatinib and nilotinib (Group Ima/Nil). Bayesian methods were used to synthesize major cytogenetic response (MCyR) and complete cytogenetic response (CCyR) from individual studies and estimate the overall response probability with 95% credible interval (CrI) for each treatment. Bayesian analysis also was used to estimate the likelihood that each treatment offers the highest probability of CCyR/MCyR based on available evidence. RESULTS Six studies evaluating bosutinib, nilotinib and ponatinib for Group Ima/Das (n= 419) and five studies evaluating bosutinib, dasatinib and ponatinib for Group Ima/Nil (n=83) were included in the analysis. All studies reported CCyR in both groups. Five studies evaluating bosutinib, nilotinib and ponatinib reported MCyR in Group Ima/Das and three studies evaluating bosutinib and ponatinib reported MCyR in Group Ima/Nil. Synthesized treatment-specific probabilities and 95% CrI for CCyR are presented in Figure 1. Synthesized treatment-specific probabilities of CCyR for Group Ima/Das were 27% for nilotinib, 20% for bosutinib and 54% (95% CrI 43%% to 66%) for ponatinib. Treatment-specific probabilities of MCyR for Group Ima/Das were 41% for nilotinib, 28% for bosutinib and 66% (95% CrI 55%% to 77%) for ponatinib. The probability of ponatinib providing superior response to all other included treatments for group Ima/Das was estimated to be >99% for both CCyR and MCyR. Synthesized treatment-specific probabilities of CCyR for Group Ima/Nil were 25% for dasatinib, 26% for bosutinib and 67% (95% CrI 51%% to 81%) for ponatinib. Treatment-specific probabilities of MCyR for Group Ima/Nil were 33% for bosutinib and 75% (95% CrI 60%% to 87%) for ponatinib. The probability of ponatinib providing superior response to all other included treatments for group Ima/Nil was estimated to be >99% for both CCyR and MCyR. CONCLUSIONS The post imatinib and dasatinib group included more studies with larger sample sizes compared with the post imatinib and nilotinib group. Overall, response rates appear higher for TKIs in the post imatinib and nilotinib group compared with the post imatinib and dasatinib group. For both groups, patients on ponatinib had higher CCyR and MCyR rates compared with the sequential 2G TKIs included in this analysis. Based on available data, ponatinib appears to provide a higher probability of treatment response for patients failing imatinib and dasatinib/ nilotinib compared with sequential 2G TKI therapy commonly used in this indication. Figure 1 Figure 1. Disclosures Lipton: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol Myers: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Ariad: Equity Ownership, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Shah:Ariad Pharmaceuticals: Research Funding. Tongbram:Ariad Pharmaceuticals: Research Funding. Sidhu:Ariad Pharmaceuticals Inc.: Research Funding. Huang:ARIAD Pharmaceuticals, Inc.: Employment, Equity Ownership. McGarry:ARIAD Pharmaceutical, Inc.: Employment, Equity Ownership. Lustgarten:ARIAD Pharmaceuticals Inc: Employment, Equity Ownership. Hawkins:Ariad Pharmaceuticals Inc.: Research Funding.

Nilotinib Shows Safety and Efficacy in Older Patients (≥ 65 years) with Newly Diagnosed Chronic Myeloid Leukemia in Chronic Phase Comparable with That in Younger Patients with Chronic Myeloid Leukemia in Chronic Phase: Results From ENESTnd,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3768-3768 ◽  
Author(s):  
Richard A. Larson ◽  
Udomsak Bunworasate ◽  
Anna G. Turkina ◽  
Stuart L. Goldberg ◽  
Pedro Dorlhiac-Llacer ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Chronic Phase ◽  
Newly Diagnosed ◽  
Employment Equity ◽  
Advisory Committees ◽  
Equity Ownership ◽  
Grade 3

Abstract Abstract 3768 Background: Data from the phase 3, randomized multicenter ENESTnd trial have demonstrated the superiority of nilotinib over imatinib after 24 months (mo) of follow-up, with significantly higher rates of complete cytogenetic response (CCyR) and major molecular response (MMR), and significantly lower rates of progression to accelerated phase/blast crisis (AP/BC). The current subanalysis evaluated the efficacy and safety of nilotinib 300 mg twice daily (Nil300) and nilotinib 400 mg twice daily (Nil400) in older (≥ 65 years [yrs] at study entry) patients (pts) with newly diagnosed chronic myeloid leukemia (CML) in chronic phase (CP) with a minimum follow-up of 24 mo. Methods: In ENESTnd, 846 pts stratified by Sokal risk score were randomized 1:1:1 to Nil300 (n = 282), Nil400 (n = 281), or imatinib 400 mg once daily (n = 283). Pts with impaired cardiac function or ECOG performance status > 2 were excluded. Rates of CCyR and MMR by 24 mo, progression to AP/BC on treatment, and safety were evaluated according to age group (< 65 vs ≥ 65 yrs) in the 2 nilotinib arms. Safety data are reported for any pt who received ≥ 1 dose of nilotinib (n = 279, Nil300; n = 277, Nil400). Results: 36 pts (13%) and 28 pts (10%) were ≥ 65 yrs old in the Nil300 and Nil400 arms, respectively. Of the pts aged ≥ 65 yrs, 51/64 (80%) had an ECOG performance status of 0 at baseline and 60/64 (94%) had intermediate or high Sokal risk scores. Of the older pts, 8 (22%) on Nil300 and 6 (21%) on Nil400 had type 2 diabetes at baseline. CCyR rates by 24 mo were 83% and 68% among older pts treated with Nil300 and Nil400, respectively, and 87% for pts aged < 65 yrs in each nilotinib arm. By 24 mo, MMR was achieved by 72% and 61% of older pts on Nil300 and Nil400, respectively; in pts aged < 65 yrs, the respective rates were 71% and 67%. All 5 pts who progressed to AP/BC on treatment (2 on Nil300 and 3 on Nil400) were aged < 65 yrs. The frequency of grade 3/4 hematologic adverse events (AEs) was low in older pts; no pts had grade 3/4 neutropenia and only 1 older pt reported grade 3/4 thrombocytopenia in each nilotinib arm (Table). Transient, asymptomatic lipase elevations were reported in 11% and 16% of older pts treated with Nil300 and Nil400, and 7% of younger pts in each arm. Hyperglycemia occurred in 23% and 16% of older pts on Nil300 and Nil400, respectively, and 4% of younger pts in each arm; regardless of age, no pt discontinued study due to hyperglycemia. Among the 12 older pts with grade 3/4 hyperglycemia (8 on Nil300; 4 on Nil400), 9 pts had type 2 diabetes at baseline. There were no QTcF increases of > 60 msec from baseline in older pts and 3 in nilotinib-treated pts < 65 yrs old (1 on Nil300; 2 on Nil400). QTcF prolongation of > 500 msec did not occur in any pt treated with nilotinib on study. Periodic echocardiograms were done, and there were no decreases of > 15% in left ventricular ejection fraction from baseline in any pt treated with nilotinib on study. There were 4 cases of ischemic heart disease reported in older pts (1/35 [3%] on Nil300; 3/25 [12%] on Nil400) and 7 cases in pts < 65 yrs of age (4/244 [2%] on Nil300; 3/252 [1%] on Nil400). No sudden deaths occurred on study. Discontinuation occurred in approximately 25% of older and younger pts with Nil300, of which, 6% and 9%, respectively, were due to AEs/lab abnormalities. Discontinuation from study with Nil400 was 46% in older pts and 19% in younger pts; of which, 36% and 10% were due to AEs/lab abnormalities. Conclusions: Older pts treated with nilotinib demonstrated high rates of cytogenetic and molecular responses and low rates of progression. Nilotinib was generally well tolerated by older pts. In older pts, Nil300 had numerically higher rates of CCyR and MMR and was generally better tolerated (as evidenced by fewer AEs and discontinuations) vs Nil400. These data support the use of Nil300 in older pts with newly diagnosed CML-CP. Disclosures: Larson: Novartis Pharmaceuticals: Consultancy, Honoraria, Research Funding. Bunworasate:Novartis Pharmaceutical: Research Funding. Turkina:Novartis: Consultancy, Honoraria; BMS: Honoraria. Goldberg:Bristol Myers Squibb: Honoraria, Research Funding, Speakers Bureau; Novartis Pharmaceutical: Honoraria, Research Funding, Speakers Bureau; Ariad: Research Funding. Dorlhiac-Llacer:Bristol Myers Squibb: Research Funding; Novartis: Research Funding. Kantarjian:Novartis: Consultancy; Novartis: Research Funding; Pfizer: Research Funding; BMS: Research Funding. Saglio:Bristol-Myers Squibb: Consultancy, Speakers Bureau; Novartis Pharmaceutical: Consultancy, Speakers Bureau; Pfizer: Consultancy. Hochhaus:Ariad: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Novartis Pharmaceutical: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria, Research Funding. Hoenekopp:Novartis Pharmaceutical: Employment, Equity Ownership. Blakesley:Novartis Pharmaceutical: Employment. Yu:Novartis: Employment, Equity Ownership. Gallagher:Novartis: Employment, Equity Ownership. Clark:Bristol Myers Squibb: Honoraria, Research Funding; Novartis Pharmaceutical: Honoraria, Research Funding, Speakers Bureau. Hughes:Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees.

scholarly journals Rapid and Robust Mobilization of CD34+ HSCs without G-CSF Following Administration of Mgta-145 Alone or in Combination with Plerixafor

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1961-1961
Author(s):  
John F. DiPersio ◽  
Jonathan Hoggatt ◽  
Steven Devine ◽  
Lukasz Biernat ◽  
Haley Howell ◽  
...  
Keyword(s):  
Single Dose ◽  
Adverse Events ◽  
Board Of Directors ◽  
Preliminary Data ◽  
Research Funding ◽  
Fold Change ◽  
Employment Equity ◽  
Advisory Committees ◽  
Cd34 Cells ◽  
Equity Ownership

Background Granulocyte colony-stimulating factor (G-CSF) is the standard of care for mobilization of hematopoietic stem cells (HSCs). G-CSF requires 4-7 days of injections and often multiple aphereses to acquire sufficient CD34+ cells for transplant. The number of CD34+ HSCs mobilized can be variable and patients who fail to mobilize enough CD34+ cells are treated with the combination of G-CSF plus plerixafor. G-CSF use is associated with bone pain, nausea, headaches, fatigue, rare episodes of splenic rupture, and is contraindicated for patients with autoimmune and sickle cell disease. MGTA-145 (GroβT) is a CXCR2 agonist. MGTA-145, in combination with plerixafor, a CXCR4 inhibitor, has the potential to rapidly and reliably mobilize robust numbers of HSCs with a single dose and same-day apheresis for transplant that is free from G-CSF. MGTA-145 plus plerixafor work synergistically to rapidly mobilize HSCs in both mice and non-human primates (Hoggatt, Cell 2018; Goncalves, Blood 2018). Based on these data, Magenta initiated a Phase 1 dose-escalating study to evaluate the safety, PK and PD of MGTA-145 as a single agent and in combination with plerixafor. Methods This study consists of four parts. In Part A, healthy volunteers were dosed with MGTA-145 (0.0075 - 0.3 mg/kg) or placebo. In Part B, MGTA-145 dose levels from Part A were selected for use in combination with a clinically approved dose of plerixafor. In Part C, a single dose MGTA-145 plus plerixafor will be administered on day 1 and day 2. In Part D, MGTA-145 plus plerixafor will be administered followed by apheresis. Results MGTA-145 monotherapy was well tolerated in all subjects dosed (Table 1) with no significant adverse events. Some subjects experienced mild (Grade 1) transient lower back pain that dissipated within minutes. In the ongoing study, the combination of MGTA-145 with plerixafor was well tolerated, with some donors experiencing Grade 1 and 2 gastrointestinal adverse events commonly observed with plerixafor alone. Pharmacokinetic (PK) exposure and maximum plasma concentrations increased dose proportionally and were not affected by plerixafor (Fig 1A). Monotherapy of MGTA-145 resulted in an immediate increase in neutrophils (Fig 1B) and release of plasma MMP-9 (Fig 1C). Neutrophil mobilization plateaued within 1-hour post MGTA-145 at doses greater than 0.03 mg/kg. This plateau was followed by a rebound of neutrophil mobilization which correlated with re-expression of CXCR2 and presence of MGTA-145 at pharmacologically active levels. Markers of neutrophil activation were relatively unchanged (<2-fold vs baseline). A rapid and statistically significant increase in CD34+ cells occurred @ 0.03 and 0.075 mg/kg of MGTA-145 (p < 0.01) relative to placebo with peak mobilization (Fig 1D) 30 minutes post MGTA-145 (7-fold above baseline @ 0.03 mg/kg). To date, the combination of MGTA-145 plus plerixafor mobilized >20/µl CD34s in 92% (11/12) subjects compared to 50% (2/4) subjects receiving plerixafor alone. Preliminary data show that there was a significant increase in fold change relative to baseline in CD34+ cells (27x vs 13x) and phenotypic CD34+CD90+CD45RA- HSCs (38x vs 22x) mobilized by MGTA-145 with plerixafor. Mobilized CD34+ cells were detectable at 15 minutes with peak mobilization shifted 2 - 4 hours earlier for the combination vs plerixafor alone (4 - 6h vs 8 - 12h). Detailed results of single dose administration of MGTA-145 and plerixafor given on one day as well as also on two sequential days will be presented along with fully characterized graft analysis post apheresis from subjects given MGTA-145 and plerixafor. Conclusions MGTA-145 is safe and well tolerated, as a monotherapy and in combination with plerixafor and induced rapid and robust mobilization of significant numbers of HSCs with a single dose in all subjects to date. Kinetics of CD34+ cell mobilization for the combination was immediate (4x increase vs no change for plerixafor alone @ 15 min) suggesting the mechanism of action of MGTA-145 plus plerixafor is different from plerixafor alone. Preliminary data demonstrate that MGTA-145 when combined with plerixafor results in a significant increase in CD34+ fold change relative to plerixafor alone. Magenta Therapeutics intends to develop MGTA-145 as a first line mobilization product for blood cancers, autoimmune and genetic diseases and plans a Phase 2 study in multiple myeloma and non-Hodgkin lymphoma in 2020. Disclosures DiPersio: Magenta Therapeutics: Equity Ownership; NeoImmune Tech: Research Funding; Cellworks Group, Inc.: Membership on an entity's Board of Directors or advisory committees; Karyopharm Therapeutics: Consultancy; Incyte: Consultancy, Research Funding; RiverVest Venture Partners Arch Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; WUGEN: Equity Ownership, Patents & Royalties, Research Funding; Macrogenics: Research Funding, Speakers Bureau; Bioline Rx: Research Funding, Speakers Bureau; Celgene: Consultancy; Amphivena Therapeutics: Consultancy, Research Funding. Hoggatt:Magenta Therapeutics: Consultancy, Equity Ownership, Research Funding. Devine:Kiadis Pharma: Other: Protocol development (via institution); Bristol Myers: Other: Grant for monitoring support & travel support; Magenta Therapeutics: Other: Travel support for advisory board; My employer (National Marrow Donor Program) has equity interest in Magenta. Biernat:Medpace, Inc.: Employment. Howell:Magenta Therapeutics: Employment, Equity Ownership. Schmelmer:Magenta Therapeutics: Employment, Equity Ownership. Neale:Magenta Therapeutics: Employment, Equity Ownership. Boitano:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Cooke:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Goncalves:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Raffel:Magenta Therapeutics: Employment, Equity Ownership. Falahee:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Morrow:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Davis:Magenta Therapeutics: Employment, Equity Ownership.

scholarly journals EZH2 Mutations and Impact on Clinical Outcome Analyzed in 1604 Patients with Acute Myeloid Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1528-1528
Author(s):  
Sebastian Stasik ◽  
Jan Moritz Middeke ◽  
Michael Kramer ◽  
Christoph Rollig ◽  
Alwin Krämer ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Employment Equity ◽  
Advisory Committees ◽  
Mutational Status ◽  
Equity Ownership ◽  
Acute Myeloid

Abstract Purpose: The enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase and key epigenetic regulator involved in transcriptional repression and embryonic development. Loss of EZH2 activity by inactivating mutations is associated with poor prognosis in myeloid malignancies such as MDS. More recently, EZH2 inactivation was shown to induce chemoresistance in acute myeloid leukemia (AML) (Göllner et al., 2017). Data on the frequency and prognostic role of EZH2-mutations in AML are rare and mostly confined to smaller cohorts. To investigate the prevalence and prognostic impact of this alteration in more detail, we analyzed a large cohort of AML patients (n = 1604) for EZH2 mutations. Patients and Methods: All patients analyzed had newly diagnosed AML, were registered in clinical protocols of the Study Alliance Leukemia (SAL) (AML96, AML2003 or AML60+, SORAML) and had available material at diagnosis. Screening for EZH2 mutations and associated alterations was done using Next-Generation Sequencing (NGS) (TruSight Myeloid Sequencing Panel, Illumina) on an Illumina MiSeq-system using bone marrow or peripheral blood. Detection was conducted with a defined cut-off of 5% variant allele frequency (VAF). All samples below the predefined threshold were classified as EZH2 wild type (wt). Patient clinical characteristics and co-mutations were analyzed according to the mutational status. Furthermore, multivariate analysis was used to identify the impact of EZH2 mutations on outcome. Results: EZH2-mutations were found in 63 of 1604 (4%) patients, with a median VAF of 44% (range 6-97%; median coverage 3077x). Mutations were detected within several exons (2-6; 8-12; 14-20) with highest frequencies in exons 17 and 18 (29%). The majority of detected mutations (71% missense and 29% nonsense/frameshift) were single nucleotide variants (SNVs) (87%), followed by small indel mutations. Descriptive statistics of clinical parameters and associated co-mutations revealed significant differences between EZH2-mut and -wt patients. At diagnosis, patients with EZH2 mutations were significantly older (median age 59 yrs) than EZH2-wt patients (median 56 yrs; p=0.044). In addition, significantly fewer EZH2-mut patients (71%) were diagnosed with de novo AML compared to EZH2-wt patients (84%; p=0.036). Accordingly, EZH2-mut patients had a higher rate of secondary acute myeloid leukemia (sAML) (21%), evolving from prior MDS or after prior chemotherapy (tAML) (8%; p=0.036). Also, bone marrow (and blood) blast counts differed between the two groups (EZH2-mut patients had significantly lower BM and PB blast counts; p=0.013). In contrast, no differences were observed for WBC counts, karyotype, ECOG performance status and ELN-2017 risk category compared to EZH2-wt patients. Based on cytogenetics according to the 2017 ELN criteria, 35% of EZH2-mut patients were categorized with favorable risk, 28% had intermediate and 37% adverse risk. No association was seen with -7/7q-. In the group of EZH2-mut AML patients, significantly higher rates of co-mutations were detected in RUNX1 (25%), ASXL1 (22%) and NRAS (25%) compared to EZH2-wt patients (with 10%; 8% and 15%, respectively). Vice versa, concomitant mutations in NPM1 were (non-significantly) more common in EZH2-wt patients (33%) vs EZH2-mut patients (21%). For other frequently mutated genes in AML there was no major difference between EZH2-mut and -wt patients, e.g. FLT3ITD (13%), FLT3TKD (10%) and CEBPA (24%), as well as genes encoding epigenetic modifiers, namely, DNMT3A (21%), IDH1/2 (11/14%), and TET2 (21%). The correlation of EZH2 mutational status with clinical outcomes showed no effect of EZH2 mutations on the rate of complete remission (CR), relapse free survival (RFS) and overall survival (OS) (with a median OS of 18.4 and 17.1 months for EZH2-mut and -wt patients, respectively) in the univariate analyses. Likewise, the multivariate analysis with clinical variable such as age, cytogenetics and WBC using Cox proportional hazard regression, revealed that EZH2 mutations were not an independent risk factor for OS or RFS. Conclusion EZH mutations are recurrent alterations in patients with AML. The association with certain clinical factors and typical mutations such as RUNX1 and ASXL1 points to the fact that these mutations are associated with secondary AML. Our data do not indicate that EZH2 mutations represent an independent prognostic factor. Disclosures Middeke: Janssen: 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; Roche: Membership on an entity's Board of Directors or advisory committees. Rollig:Bayer: Research Funding; Janssen: Research Funding. Scholl:Jazz Pharma: Membership on an entity's Board of Directors or advisory committees; Abbivie: Other: Travel support; Alexion: Other: Travel support; MDS: Other: Travel support; Novartis: Other: Travel support; Deutsche Krebshilfe: Research Funding; Carreras Foundation: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees. Hochhaus:Pfizer: Research Funding; Incyte: Research Funding; Novartis: Research Funding; Bristol-Myers Squibb: Research Funding; Takeda: Research Funding. Brümmendorf:Janssen: Consultancy; Takeda: Consultancy; Novartis: Consultancy, Research Funding; Merck: Consultancy; Pfizer: Consultancy, Research Funding. Burchert:AOP Orphan: Honoraria, Research Funding; Bayer: Research Funding; Pfizer: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding; Novartis: Research Funding. Krause:Novartis: Research Funding. Hänel:Amgen: Honoraria; Roche: Honoraria; Takeda: Honoraria; Novartis: Honoraria. Platzbecker:Celgene: Research Funding. Mayer:Eisai: Research Funding; Novartis: Research Funding; Roche: Research Funding; Johnson & Johnson: Research Funding; Affimed: Research Funding. Serve:Bayer: Research Funding. Ehninger:Cellex Gesellschaft fuer Zellgewinnung mbH: Employment, Equity Ownership; Bayer: Research Funding; GEMoaB Monoclonals GmbH: Employment, Equity Ownership. Thiede:AgenDix: Other: Ownership; Novartis: Honoraria, Research Funding.

ABT-737 Targets Leukemic Stem Cells In Mouse Models of Mutant NRASD12/hBCL-2- Mediated Acute Myeloid Leukemia Progression with Increased Survival

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3308-3308
Author(s):  
Rose Ann Padua ◽  
Stephanie Beurlet ◽  
Patricia Krief ◽  
Nader Omidvar ◽  
Carole Le Pogam ◽  
...  
Keyword(s):  
Stem Cells ◽  
Disease Progression ◽  
Board Of Directors ◽  
Research Funding ◽  
Leukemic Stem Cells ◽  
Spleen Cells ◽  
Employment Equity ◽  
Advisory Committees ◽  
Equity Ownership ◽  
Bh3 Mimetic

Abstract Abstract 3308 Background: Animal models enable us to understand disease progression and provide us with reagents to test various therapeutic strategies. We have previously developed a mouse model of myelodysplasia/acute myelogenous leukemia (MDS/AML) progression using mutant NRASD12 and overexpression of human hBCL-2 (Omidvar et al Cancer Res 67:11657-67, 2007). Expanded leukemic stem cells (LSC) were identified as Lin-/Sca1+/KIT+ (LSK) populations, with increased myeloid colony growth and were transplantable. Increased hBCL-2 and RAS-GTP complex were observed in both MDS/AML diseases. The MDS-like disease had increased apoptosis, whilst the AML-like mice had liver apoptosis patterns similar to wild type. The single NRASD12 line also had increased apoptosis. In this present study using a BCL-2 homology domain 3 (BH3) mimetic ABT-737 (Abbott), we have evaluated the effects of targeting BCL-2 in our preclinical models. Methods & Results: Treatment with the inhibitor shows a reduction of LSK cells, reduced progenitor numbers in colony assays and clearance of the liver infiltrations in both MDS and AML models. Gene expression profiling of the MDS mice shows regulation of 399 genes upon treatment including 58 genes expressed by the single mutant RAS mice and not expressed in the untreated AML mice. 78 genes were shared between single NRASD12 and diseased mice and not the treated mice. These studies potentially identify the contribution of NRASD12 genes to disease progression. By confocal microscopy we observed that in the MDS mice the majority of the RAS and BCL-2 co-localized to the plasma membrane, where active pro-apoptotic RAS is normally located, whereas in the AML disease RAS and BCL-2 co-localized in the mitochondria, where BCL-2 is normally found (Omidvar et al 2007). After treatment with the inhibitor the AML co-localization of RAS and BCL-2 shifted to the plasma membrane where single NRASD12 is normally localized. Furthermore, increased RAS-GTP levels was detected in both Sca1+ and Mac1+ enriched spleen cells and interestingly an increase in BCL-2 expression was observed in peripheral blood and in spleen cells after treatment; this increase in BCL-2 was associated with a decrease in the phosphorylation of serine 70 and an increase in phosphorylation of threonine 56 of BCL-2. ABT-737 treatment led to increased phosphorylated ERK resembling RAS and reduced MEK and AKT phosphorylation, changes detected by western blots and the nanoimmunoassay (NIA, NanoPro, Cell Biosciences) that might account for the increased apoptosis, measured by TUNEL and In vivo imaging by single-photon emission computed tomography (SPECT) using Tc-99m-labelled AnnexinV (SPECT). In contrast, although treated MDS mice had increased apoptosis they did not have an increase in overall expression of BCL-2 or in RAS-GTP levels. Treatment of both MDS and AML models with this inhibitor significantly extended lifespan from diagnosis with mean survival of 28 days untreated vs 80 days treated (p=0.0003) and mean survival from birth of 39 untreated vs 85 days treated (p<0.0001) respectively Conclusions: Genomics, proteomics and imaging have been employed in the MDS/AML models to characterize disease progression and follow response to treatment to the BH3 mimetic ABT-737 in order to gain molecular insights in the evaluation of the efficacy. ABT-737 appears to target LSCs, induce apoptosis, regulating RAS and BCL-2 signalling pathways, which translated into significantly increased survival. Disclosures: Padua: Vivavacs SAS: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Auboeuf:GenoSplice technology: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. de la Grange:GenoSplice technology: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Fenaux:Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Janssen Cilag: Honoraria, Research Funding; ROCHE: Honoraria, Research Funding; AMGEN: Honoraria, Research Funding; GSK: Honoraria, Research Funding; Merck: Honoraria, Research Funding; Cephalon: Honoraria, Research Funding. Tu:Cell Biosciences Inc;: Employment. Yang:Cell Biosciences Inc;: Employment. Weissman:Amgen, Systemix, Stem cells Inc, Cellerant: Consultancy, Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Felsher:Cell Bioscience:. Chomienne:Vivavacs SAS: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

scholarly journals Nascent Transcript and Single Cell Rnaseq Analysis Defines the Mechanism of Action of the LSD1 Inhibitor INCB059872 in Myeloid Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2509-2509
Author(s):  
Gretchen Johnston ◽  
Haley E. Ramsey ◽  
Kristy Stengel ◽  
Shilpa Sampathi ◽  
Pankaj Acharya ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Drug Treatment ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Myeloid Differentiation ◽  
Employment Equity ◽  
Advisory Committees ◽  
Equity Ownership ◽  
Upregulated Genes

Drugs targeting chromatin-modifying enzymes have entered clinical trials for myeloid malignancies, including INCB059872, a selective irreversible inhibitor of Lysine-Specific Demethylase 1 (LSD1). LSD1 is a component of the CoREST complex, in which it associates with histone deacetylases 1 and 2, the transcriptional co-repressor, mSin3A or mSin3B, and the REST corepressor (RCOR1), so a role in gene expression was expected. While initial studies of LSD1 inhibitors have suggested these compounds may be used to induce differentiation of acute myeloid leukemia, the mechanisms underlying this effect and dose-limiting toxicities are not well understood. Here, we have used precision nuclear run-on sequencing (PROseq) and single-cell RNA-sequencing (scRNAseq) to show that INCB059872 de-represses GFI1/GFI1B-regulated genes to promote a myeloid differentiation gene signature in AML cells while stalling maturation of megakaryocyte progenitor cells. Within 3 days of treatment with INCB059872, the majority of THP-1, which contain an the MLL-translocation, undergo myeloid differentiation. RNAseq analysis indicated that 24h drug treatment upregulated genes involved in hematopoietic cell lineage, which is consistent with the differentiation. In addition, PROseq was used to measure the effects of INCB059872 on nascent transcription at genes and enhancers, as this is one of the best methods to define enhancer activity. In THP-1 cells after 24h treatment, there were 203 genes with at least a 1.5-fold increase in transcription, while there are nearly 1300 enhancers meeting this threshold. Upregulated genes include those associated with myeloid cell differentiation, such as CSF1R and CD86. Given that LSD1 catalyzes the removal of mono- and di-methyl marks from histone H3, we expected that INCB059872 would cause a buildup of histone methylation. Surprisingly, ChIPseq for H3K4me2 and H3K4me1 showed only subtle changes in these marks after 48h drug treatment in THP-1. Only a handful of LSD1i-induced enhancers overlapped with detectable changes in H3K4 methylation. However, our PROseq data is consistent with the increases in H3K27 acetylation seen with OG86 (a compound that disrupts the LSD1:GFI1 interaction) at GFI1 binding sites (PMID: 29590629). Indeed, motif analysis of INCB059872-upregulated enhancers identified the GFI1 recognition sequence as the most highly enriched. Moreover, siRNA inhibition of key components of LSD1-containing chromatin remodeling complexes pinpointed the CoREST complex as mediating the THP-1 myeloid differentiation effects of INCB059872. To investigate on-target thrombocytopenia seen with LSD1 inhibitors in preclinical studies, we analyzed the bone marrow of wild-type mice treated daily with INCB059872 for 0, 4, or 6 days before harvesting and sorting lin-bone marrow cells for scRNA-seq. Notably, one of the most highly upregulated genes in treated cells was Gfi1b. Unsupervised clustering identified 22 clusters, corresponding to unique subpopulations (Fig. 1A). While the distribution of cells into different progenitor populations was mostly unaffected by drug treatment, these data revealed a striking increase in the proportion of cells from treated mice assigned to a megakaryocyte stem/progenitor cluster. Cells within this expanded cluster expressed stem cell markers such as MYCN and PBX1, but also expressed VWF (Fig. 1B). Thus, LSD1 inhibition caused accumulation of megakaryopoiesis-biased stem cells that failed to mature into efficient platelet producers. Finally, we used scRNAseq to analyze bone marrow from an AML patient who responded to treatment with INCB059872 plus azacytidine (AZA). A pre-treatment bone marrow sample was divided into separate cultures to study the effects of INCB059872, AZA, or the combination. Remarkably, unsupervised clustering of patient cells assigned the majority of INCB059872 and combination-treated cells to clusters that were not found in control- or AZA-treated samples. Cells exposed to INCB059872 had upregulated GFI1 and GFI1B, as well as differentiation-related genes that were also observed in AML cell lines. Overall, these data indicate that INCB059872 affects gene expression with kinetics consistent with a loss of CoREST activity to stimulate differentiation of AML blasts, but the inactivation of GFI1/GFI1B impairs megakaryocyte maturation likely explaining thrombocytopenia seen in preclinical models. Disclosures Stubbs: Incyte Corporation: Employment, Equity Ownership. Burn:Incyte: Employment, Equity Ownership. Hiebert:Incyte Corporation: Research Funding. Savona:Karyopharm Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Selvita: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sunesis: Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Boehringer Ingelheim: Patents & Royalties; AbbVie: Membership on an entity's Board of Directors or advisory committees.

scholarly journals LAM-003, a Novel Oral Heat Shock Protein 90 Inhibitor for Treatment of Acute Myeloid Leukemia, Including Wild-Type and FMS-like Tyrosine Kinase 3 (FLT3)-Mutant Disease

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2664-2664
Author(s):  
Neil Beeharry ◽  
Sean Landrette ◽  
Jeff Grotzke ◽  
Sophia Gayle ◽  
Marylens Hernandez ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Cell Lymphoma ◽  
Heat Shock Protein 90 ◽  
Wild Type ◽  
Employment Equity ◽  
Advisory Committees ◽  
Animal Survival ◽  
Equity Ownership

Acute myeloid leukemia (AML) remains a disease with high unmet medical need. While most patients respond to initial therapy, few are cured, relapse rates are high, and most patients eventually develop life-threatening complications. FLT3-mutant disease is a particularly aggressive subtype. Recent approval of drugs targeting FLT3-mutant disease have improved short-term outcomes but not all patients respond, and duration of response is limited by secondary mutations that impede FLT3 inhibitor (FLT3i) binding (intrinsic factors) and by secreted stromal factors that activate alternative pro-survival pathways (extrinsic factors). Heat-shock protein 90 (HSP90) is a chaperone protein involved in many cellular processes and inhibition of HSP90 can have pleiotropic effects in targeting cancer cells such as degradation of oncoproteins that drive survival and proteins that mediate protective signaling. Here, we describe the nonclinical activity of LAM-003, an orally bioavailable HSP90 inhibitor (HSP90i) under clinical development for AML. To assess the anti-leukemic activity of LAM-003, we tested a panel of AML cell lines and primary AML samples. LAM-003 inhibited proliferation of both FLT3-mutant and wild-type cell lines, with preferential activity against cells harboring FLT3-ITD (geometric mean FLT3-ITD EC50 = 670 nM [n=8] vs FLT3 WT EC50 = 1400 nM [n=16]). Additionally, we observed that LAM-003 was potent in a subset of the FLT3 WT cells. To explore whether LAM-003 was effective against tumors driven by oncoproteins that are client proteins of HSP90, we focused on AML cells harboring FLT3-ITD. We confirmed that LAM-003 reduced cell surface FLT3-ITD expression and downstream signaling in MV-4-11 and MOLM-13 cells, consistent with HSP90i-mediated degradation of FLT3-ITD. In BA/F3 cells expressing FLT3-ITD with various secondary resistance mutations, we observed that LAM-003 elicited a dose-dependent reduction of FLT3 mutant cell surface expression. Moreover, BA/F3 cells expressing FLT3-ITD and the F691L mutation exhibited the expected resistance to crenolanib, yet LAM-003 retained anti-proliferative activity. Additionally, MOLM-13 cells harboring a FLT3 D835Y mutation demonstrated expected resistance to the FLT3i sorafenib and tandutinib yet remained sensitive to LAM-003. Finally, primary AML blasts harboring a D835 mutation displayed sensitivity to LAM-003 when tested ex vivo. To evaluate the potential of LAM-003 to overcome bone-marrow-stroma-derived resistance, FLT3-ITD AML cell lines (MV-4-11, MOLM-13, MOLM-14) were assayed in unconditioned or stromal-cell-conditioned medium. Conditioned medium dramatically reduced the potency of FLT3i but LAM-003 demonstrated equal potency under both conditions. We also showed that stromal cell co-culture induced FLT3i resistance in MOLM-13 cells whereas LAM-003 retained potent activity. Recognizing that the inherent genetic heterogeneity of AML blasts limits the curative potential of a single drug, we performed in vitro studies to identify drugs that synergize with LAM-003 in 3 FLT3-ITD AML cell lines. Synergy was demonstrated with FLT3i, daunorubicin, azacitidine or cytarabine, with the most robust synergy being observed with venetoclax. Extending the evaluation to AML cells wild type for FLT3 and cell lines from other hematologic indications (multiple myeloma, diffuse large B-cell lymphoma and mantle cell lymphoma), we found that the synergy was not limited to cells harboring FLT3-ITD, but rather correlated with BCL-2 abundance, suggesting a fundamental mechanism of action that depends on BCL-2 family-mediated survival. Mechanistic studies demonstrated that the combination of LAM-003 and venetoclax inhibited AKT-mediated regulation of GSK3B, resulting in MCL-1 degradation. In vivo studies using a MOLM-13 systemic model of FLT3-ITD AML demonstrated that LAM-003 monotherapy significantly improved animal survival and that the combination of LAM-003 and venetoclax significantly prolonged animal survival compared with each single agent. These nonclinical studies demonstrate that LAM-003 exhibits antileukemic activity, overcomes mechanisms of FLT3i resistance and potently synergizes with existing AML drugs. As such, our data provide strong rationale for evaluation of LAM-003 in an ongoing clinical trial in patients with AML (NCT03426605). Disclosures Beeharry: AI Therapeutics: Employment, Equity Ownership. Landrette:AI Therapeutics: Employment. Grotzke:AI Therapeutics: Employment. Gayle:AI Therapeutics: Equity Ownership. Young:AI Therapeutics: Employment, Equity Ownership. Miller:Incuron, Inc.: Consultancy; Cleveland Biolabs, Inc: Employment, Equity Ownership; Calistoga Pharmaceuticals, Inc.: Equity Ownership; AI Therapeutics: Consultancy, Equity Ownership; VelosBio Inc.: Employment, Equity Ownership; Acerta Pharma, Inc.: Equity Ownership. Xu:AI Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Rothberg:AI Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Lichenstein:AI Therapeutics: Employment, Equity Ownership.

Antibody-Targeting of IL-3 Receptor-α Increases the Susceptibility of CD34+ CML Progenitors to Dasatinib-Induced Cell Death,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3745-3745
Author(s):  
Eva Nievergall ◽  
Deborah L. White ◽  
Hayley Ramshaw ◽  
Angel F. Lopez ◽  
Timothy P. Hughes ◽  
...  
Keyword(s):  
Stem Cells ◽  
Flow Cytometry ◽  
Progenitor Cells ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Advisory Committees ◽  
Cd34 Cells

Abstract Abstract 3745 Despite the remarkable efficacy of tyrosine kinase inhibitors (TKIs) in the treatment of chronic myeloid leukemia (CML), Ph+ CD34+ progenitor cells remain detectable even in patients with stable complete cytogenetic response. Over 40% of patients in stable complete molecular remission will develop molecular relapse within 6 months of stopping imatinib. While the exact causes are largely unknown, one of the proposed mechanisms is the protection of leukemic stem and early progenitor cells by the paracrine or autocrine production of cytokines, such as IL-3, GM-CSF and G-CSF, which activate survival pathways that bypass TKI-induced cytocidal effects. In acute myeloid leukemia (AML), the IL-3 receptor α chain (CD123) is recognized as a specific marker for CD34+/CD38− stem cells and therefore is attracting increasing interest as a therapeutic target. However, the function of CD123 in CML remains to date mostly unexplored. The aim of this study is to investigate potential synergy between TKIs and CSL362 (a humanized antibody version of 7G3 against CD123) in targeting CML progenitor and stem cells. CD34+ and CD34+/CD38− cells were isolated from mononuclear cells of newly diagnosed CML chronic phase and blast crisis patients. Flow cytometry studies indicated significantly increased CD123 expression on CD34+/CD38− cells of CML patients in both chronic phase and blast crisis when compared to normal hematopoietic stem cells (p<0.01 and p<0.001 for chronic phase and blast crisis, respectively; Figure A). A functional relevance of increased CD123 expression was demonstrated by IL-3-dependent increase in STAT5 phosphorylation (260.5% of baseline with 20 ng/ml IL-3; n=12; p<0.001) in CML CD34+ cells. Dasatinib inhibits STAT5 phosphorylation by blocking BCR-ABL signaling but only in the absence of IL-3 (62.5% of baseline for dasatinib alone vs. 130.8% for dasatinib + IL-3; n=3; p<0.01). In agreement, IL-3 effectively rescues dasatinib-induced cell death, as evaluated by AnnexinV/7-AAD staining (103.3% vs. 72.45%, n=5; p<0.01) and CFU-GM colony forming assays (69.39% vs. 46.13% relative to no treatment control; n=4; p<0.05). CSL362, in turn, revokes IL-3-mediated STAT5 phosphorylation (37.12% vs. 130.8%; n=3; p<0.001) and cytoprotection (45.05% vs. 69.39% CFC; n=4; p<0.01). In order to further elucidate the role of CSL362, CML CD34+ cells were cultured with increasing concentrations of dasatinib in the presence of IL-3 and CSL362 or BM4 isotype-matched control antibody. Even at very low dasatinib concentrations, CSL362 significantly reduces CML CD34+ colony forming cells (p<0.05; Figure B). Together these results substantiate a relevant role for IL-3-mediated resistance in CML progenitor cells and additionally confirming the ability of CSL362 to effectively bind to CD123 and impede IL-3 function. CSL362 furthermore has been optimized to mediate antibody dependent cell cytotoxicity (ADCC). CSL362 causes specific cell lysis of CML CD34+ progenitor cells in co-culture with allogeneic Natural killer cells as determined by increased lactate dehydrogenase release (ADCC activity of 42.4% ± 8.1%; n=3) and a decrease in the number of CFU-GM colonies by 74.1 % ± 12.2% (n=3). Collectively, our results indicate that a combination of dasatinib and CSL362 inhibits CML progenitor cell survival more effectively in vitro. Therefore, targeting IL-3 receptor α with CSL362 in chronic phase and blast crisis CML patients might provide a novel specific treatment approach aiding the elimination of refractory chronic myeloid leukemic stem and progenitor cells. A: Flow cytometry analysis reveals that CD123 expression is significantly higher in CD34+/CD38− cells of CML patients in chronic phase (CML-CP) and blast crisis (BC-CML) as compared to normal patients (NP), as previously documented for AML patients. ** p<0.01, *** p<0.001 by unpaired, two-tailed Student's t-test. B: In the presence of IL-3, CSL362 significantly reduces the number of colony forming cells. CD34+ cells of de novo CML-CP patients were cultured with dasatinib (0 to 10 nM) +IL-3 (1 ng/ml) ± CSL362 or BM4 (isotype control for CSL362). After 72 hours of culture live cells were plated for CFU-GM assay and colonies were counted after 2 weeks. Mean ± SE of three independent experiments is shown, n=4, p<0.05 by two-way ANOVA. Disclosures: Nievergall: CSL: Research Funding. White:CSL: Research Funding. Lopez:CSL: Research Funding. 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; Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Hiwase:CSL: Research Funding.

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