scholarly journals Characterization of Synergistic Selinexor Combinations of Dexamethasone, Pomalidomide, Elotuzumab and Daratumumab in Primary MM Samples Ex Vivo

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 29-30
Author(s):  
Kenneth H. Shain ◽  
Rafael Renatino-Canevarolo ◽  
Mark B. Meads ◽  
Praneeth Reddy Sudalagunta ◽  
Maria D Coelho Siqueira Silva ◽  
...  

Introduction. Multiple myeloma (MM) is an incurable plasma cell malignancy with a growing list of anti-MM therapeutics. However, the development of predictive biomarkers has yet to be achieved for nearly all MM therapeutics. Selinexor (SELI), a nuclear export inhibitor targeting exportin 1 (XPO1), has been approved with dexamethasone (DEX) in penta-refractory MM. Clinical studies investigating promising SELI- 3 drug combinations are ongoing. Here, we have investigated potential synergistic combinations of SELI and anti-MM agents in terms of ex vivo sensitivity, as well as paired RNAseq and WES to identify companion biomarkers. Methods. MM cells isolated from fresh bone marrow aspirates were tested for drug sensitivity in an organotypic ex vivo drug sensitivity assay, consisting of co-culture with stroma, collagen matrix and patient-derived serum. Single agents were tested at 5 concentrations, while two-drug combinations were tested at fixed ratio of concentrations. LD50 and area under the curve (AUC) were assessed during 96h-exposure as metrics for drug resistance. Drug synergy was calculated as a modified BLISS model. Matching aliquots of MM cells had RNAseq and WES performed through ORIEN/AVATAR project. Geneset enrichment analysis (GSEA) was conducted using both AUC and LD50 as phenotypes for single agents and combinations. Both curated pathways (KEGG and cancer hallmarks) and unsupervised gene clustering were used as genesets. Student t-tests with multiple test correction were used to identify non-synonymous mutations in protein coding genes associated with single agent or combination AUC. Results. For this analysis, a cohort of specimens from 103 patients (48% female, 4% Hispanic, 11% African American) was tested with SELI and/or DEX. with a median of 2 lines of therapy (0-12). A smaller cohort of 37 have been examined with SELI, pomalidomide (POM), elotuzumab (ELO) and daratumumab (DARA). Within this cohort we observed synergy between SELI and DEX, POM and ELO as shown in Figure 1. The volcano plot illustrates the number of samples, maximum drug concentration, as well as magnitude (x- axis) and significance (y- axis) of synergy. Although the SELI-DARA combination trended toward synergy, statistical significance was not achieved. To identify molecular mechanisms and biomarkers associated with sensitivity to SELI and SELI- combinations, we investigated paired RNAseq and WES with ex vivo sensitivity. Initially, we conducted GSEA on two cohorts of primary MM samples tested with SELI alone at 5µM (n=53) and 10µM (n=50). Cell adhesion (KEGG CAMS), inflammatory cytokines (KEGG ASTHMA), and epithelial mesenchymal transition (HALLMARK EMT) were associated with resistance in both cohorts, while the HALLMARK MYC TARGETS was associated with sensitivity (FWER p<0.05). Mutational analysis identified 46 gene mutations associated with SELI resistance and 100 associated with sensitivity at 5µM, and 87 and 27 mutations associated with SELI resistance and sensitivity, respectively, at 10µM. Two gene mutations were identified in both cohorts: BCL7A, involved in chromatin remodeling, was associated with sensitivity and CEP290, a microtubule binding protein, associated with resistance (p<0.05). Analysis of both gene sequences (NetNES 1.1) identified nuclear export signal (NES) residues suggesting these may be XPO1 cargo. Additionally, translocation t(11;14) was associated with SELI resistance in the 5µM cohort (p=0.037). The completed set of 50 specimens ex vivo, RNAseq and WES analysis will be mature and updated for the potential presentation at ASH. Conclusions. We observed ex vivo synergy between SELI and DEX, POM and ELO. Molecular analysis of matched ex vivo drug sensitivity, transcriptome and mutational profile identified environment-mediated drug resistance pathways positively correlated with SELI single agent resistance, as well as MYC regulated genes associated with ex vivo sensitivity. We also identified a list of mutations associated with SELI drug resistance and sensitivity, with special emphasis on two novel NES-containing genes, CEP290 and BCL7A. The next step of this project is to analyze transcriptional and mutational patterns associated with ex vivo synergy in the combinations here described, as putative biomarkers for future clinical investigation. Disclosures Shain: Amgen: Speakers Bureau; Adaptive: Consultancy, Honoraria; Karyopharm: Research Funding, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; GlaxoSmithKline: Speakers Bureau; Janssen: Honoraria, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi/Genzyme: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; AbbVie: Research Funding. Kulkarni:M2GEN: Current Employment. Zhang:M2GEN: Current Employment. Hampton:M2GEN: Current Employment. Argueta:Karyopharm: Current Employment. Landesman:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company. Siqueira Silva:AbbVie: Research Funding; NIH/NCI: Research Funding; Karyopharm: Research Funding.

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 12-14
Author(s):  
James T Dibb ◽  
Nicola Long ◽  
Christopher A. Eide ◽  
Stephen E Kurtz ◽  
Cristina E. Tognon ◽  
...  

Patterns of Venetoclax Sensitivity in Chronic Lymphocytic Leukemia Chronic lymphocytic leukemia (CLL) is predominantly a disease of older adults. The 5-year overall survival is 70-91%, depending on Rai/Binet stage at diagnosis (80% overall), and although a subset of CLL takes a very indolent course, it can be aggressive as well. Disease course and responsiveness to therapeutic agents may be predictable, to some degree, based on specific genetic lesions or other patient population characteristics. Monotherapies targeting specific cell pathways are rapidly increasing in prevalence. Ibrutinib (Bruton tyrosine kinase inhibitor) has shown promise as a single agent as well as in combination with other agents. In particular, ibrutinib has shown efficacy in combination with venetoclax (inhibitor of cell death suppressor BCL2). This combination appears to be particularly potent in patients with a del(11q) karyotype. Cytogenetic information is used already in several other leukemias to inform prognosis and treatment. Although CLL is a disease of monoclonal proliferation, precise definition of the diseased clone will allow for more individualized treatment. Stratification of drug sensitivity based on genetic and cytogenetic features will directly affect patient outcomes in CLL. Primary patient mononuclear cells (from either peripheral blood or bone marrow) were plated ex vivo with a panel of 49 drug combinations and the 16 respective single agents (SA) in 384-well plates using 10,000 cells/well. Drugs were tested in 7-point concentration series; wells with drug combinations were added at fixed molar ratios. Cell viability was assessed after a 72 hour culture period. In this assay, primary cells maintain viability but do not proliferate. In CLL, the most frequent mutations were: del(17p); del(11q); del(13q14); trisomy 12; complex karyotype (at least three chromosomal aberrations). Selected analysis of these data from 157 unique patients were performed by isolating the most potent inhibitors (defined by lowest median AUC) either as a single agent or in combination with known treatments. These were evaluated with nonparametric tests (Kruskal-Wallace, Mann-Whitney, Spearman rank coefficient) on the statistical software Prism. By subdividing the data by available genetic and cytogenetic information, patterns that have not been previously described in the literature emerged. In the cohort of patients with any karyotypic abnormality (not complex karyotype), SA venetoclax and the combination of venetoclax-ibrutinib (VEN/IBRUT) were equivalently effective with no significant difference in efficacy observed between SA venetoclax and the combination. As previously described, del(11q) independently predicts increased efficacy of SA venetoclax and VEN/IBRUT, and this efficacy was validated by ex vivo potency here as well. However, we show that male gender is an independent predictor of potency in both SA venetoclax and VEN/IBRUT as well. Interestingly, doramapimod (an inhibitor of p38 MAP kinase) was not particularly potent as a SA, however, the combination of venetoclax-doramapimod (VEN/DORA) proved to be the most potent of all combinations tested, more potent than even VEN/IBRUT. This effect could not be replicated in any subgroup, as VEN/DORA samples for the entire cohort were relatively limited (n=31). Although this analysis has inherent limitations, including underpowered data to analyze in less frequent cytogenetic events (e.g. del(6q)), we did find significant patterns of potency. These may or may not translate to clinical efficacy in CLL and do not address any potential toxicity. However, these data suggest future directions for more targeted research on these drugs and drug combinations. Disclosures Tyner: Petra:Research Funding;Janssen:Research Funding;Seattle Genetics:Research Funding;Incyte:Research Funding;Genentech:Research Funding;Constellation:Research Funding;AstraZeneca:Research Funding;Aptose:Research Funding;Gilead:Research Funding;Takeda:Research Funding;Syros:Research Funding;Agios:Research Funding;Array:Research Funding.Druker:EnLiven:Consultancy, Research Funding;Gilead Sciences:Consultancy, Membership on an entity's Board of Directors or advisory committees;Cepheid:Consultancy, Membership on an entity's Board of Directors or advisory committees;Dana-Farber Cancer Institute:Patents & Royalties;Bristol-Myers Squibb:Research Funding;Blueprint Medicines:Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees;Aptose Therapeutics Inc. (formerly Lorus):Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees;ARIAD:Research Funding;Third Coast Therapeutics:Membership on an entity's Board of Directors or advisory committees;The RUNX1 Research Program:Membership on an entity's Board of Directors or advisory committees;Pfizer:Research Funding;Patient True Talks:Consultancy;Oregon Health & Science University:Patents & Royalties;Novartis Pharmaceuticals:Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding;MolecularMD (acquired by ICON):Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees;Millipore (formerly Upstate Biotechnology):Patents & Royalties;VB Therapeutics:Membership on an entity's Board of Directors or advisory committees;Vivid Biosciences:Membership on an entity's Board of Directors or advisory committees;ALLCRON:Consultancy, Membership on an entity's Board of Directors or advisory committees;Amgen:Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees;Aileron Therapeutics:Membership on an entity's Board of Directors or advisory committees;Merck & Co:Patents & Royalties;McGraw Hill:Patents & Royalties;GRAIL:Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees;Henry Stewart Talks:Patents & Royalties;Iterion Therapeutics (formerly Beta Cat Pharmaceuticals):Membership on an entity's Board of Directors or advisory committees;Leukemia & Lymphoma Society:Research Funding.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 865-865 ◽  
Author(s):  
Stephen E Kurtz ◽  
Elie Traer ◽  
Jakki Martinez ◽  
Andrew Park ◽  
Jake Wagner ◽  
...  

Abstract Introduction: The intratumoral heterogeneity of Acute Myeloid Leukemia (AML) and other hematologic malignancies presents a challenge in developing effective single-agent targeted treatments. Furthermore, the emergence of genetically heterogeneous subclones leading to relapse suggests that effective therapies associated with discrete genotypes may require drug combinations, each of which modulates distinct pathways. In addition, microenvironmental rescue signals as well as tumor-intrinsic feedback pathways in AML and other hematologic malignancy subsets will necessitate combinatorial therapy approaches. Towards the goal of identifying new therapeutic combinations for AML and other hematologic malignancies, we assessed the sensitivity of primary patient samples to various drug combinations using an ex vivo functional platform. Methods: We have previously screened over 1000 primary patient specimens against a panel of single-agent small-molecule inhibitors. Using these historical drug sensitivity data, we ranked drugs by their IC50, and used these rankings to assemble an initial panel (1) of 44 drug combinations consisting primarily of kinase inhibitors with non-overlapping pathways. Primary patient samples (n = 74) with various hematologic malignancies were assessed for sensitivities to these combinations by culturing cells in the presence of fixed molar concentrations of the drugs over a dose series. Sensitivity was assessed by a viability assay on day 3 using a tetrazolium reagent. IC50 values for samples sensitive to a combination were sorted according to disease type and compared to those for each single agent to derive an index of effectiveness. Based on data from panel 1, we generated a second panel (2) consisting of 44 drug combinations, including new combinations of kinase inhibitors as well as combinations of drugs from different classes, such as bromodomain inhibitors, BH3 mimetics, proteasome inhibitors, IDH1/2 inhibitors coupled with kinase inhibitors. Primary patient samples (n = 78) were assessed for sensitivities to these combinations. Results: The performance of drug combinations across AML, ALL, CLL, CML or other MDS/MPN specimens are displayed in a heat map (Figure 1) representing the sensitivities of each drug combination relative to either of the single agents comprising that combination (the combination IC50 divided by the lowest single agent IC50 is our combination ratio). For each combination, we then compared the combination ratio of each individual specimen to the median combination ratio across all specimens tested, and cases with a combination ratio value less than 20% of the median were considered hypersensitive to that combination. We calculated the percentage of cases that were sensitive to each combination within the diagnostic subsets of AML, ALL, CLL, CML, and MDS/MPN and subsets with the most frequent sensitivity to a drug combination are indicated on the heat map (<20%, dark red; 20-50%, dark pink; 50-80%, light pink; and >80%, white). Combinations of two kinase inhibitors that included the p38MAPK inhibitor, doramapimod, were generally more effective on AML and CLL samples than other diagnostic subsets (panel 1). For CLL sample, combinations including midostaurin and either alisertib, ruxolitinib or sorafenib were particularly effective. Among combinations on panel 2, doramapimod coupled with an apoptosis inducer (ABT-199) exhibited broad efficacy on AML samples. In addition, combinations with the bromodomain inhibitor, JQ1, or the BH3 mimetic, ABT-199, were more broadly effective across diagnostic subsets than many of the kinase-kinase pairs tested. To validate the apparent synergies observed with patient samples, we tested selected combinations on AML-derived cell lines and observed synergies, which were supported with combination indices derived by the Chou-Talalay method. Conclusions: These data suggest that specific drug combinations formed either with two kinase inhibitors or with two compounds from different drug classes are effective in a patient-specific manner with enrichment for certain drug pairs within specific diagnostic subsets. While a secondary evaluation is necessary to validate the initial observation of sensitivity, linking this methodology with genetic attributes for patient samples will identify effective combinations of targeted agents and add therapeutic options for AML treatment. Figure 1. Figure 1. Disclosures Pandya: Microsoft: Employment, Equity Ownership. Bolosky:Microsoft: Employment, Equity Ownership. Druker:Oregon Health & Science University: Patents & Royalties; Henry Stewart Talks: Patents & Royalties; CTI Biosciences: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals: Research Funding; Aptose Therapeutics, Inc (formerly Lorus): Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; McGraw Hill: Patents & Royalties; Leukemia & Lymphoma Society: Membership on an entity's Board of Directors or advisory committees, Research Funding; MolecularMD: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Roche TCRC, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Research Funding; Millipore: Patents & Royalties; AstraZeneca: Consultancy; Oncotide Pharmaceuticals: Research Funding; Cylene Pharmaceuticals: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Fred Hutchinson Cancer Research Center: Research Funding; ARIAD: Research Funding; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sage Bionetworks: Research Funding. Tyner:Incyte: Research Funding; Janssen Pharmaceuticals: Research Funding; Constellation Pharmaceuticals: Research Funding; Array Biopharma: Research Funding; Aptose Biosciences: Research Funding.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1301-1301
Author(s):  
Christopher A. Eide ◽  
Stephen E. Kurtz ◽  
Andy Kaempf ◽  
Nicola Long ◽  
Daniel Bottomly ◽  
...  

Abstract The development of molecularly-targeted therapies to improve outcomes relative to chemotherapy for acute myeloid leukemia (AML) is impeded by the heterogeneity of genetic aberrations that contribute to disease. Among the multitude of biological mechanisms that lead to AML disease initiation and progression is dysregulation of cytokine signaling pathways, a hallmark of chronic inflammation, which contribute to the growth, survival, and differentiation state of AML cells. We have previously shown that IL-1β, a pro-inflammatory cytokine expressed by many cell types including macrophages and monocytes, stimulates proliferation of leukemic blasts independent of mutational status in primary AML samples via enhanced phosphorylation of p38α MAPK, an effect that can be blocked by IL-1 receptor knockdown or by pharmacologic inhibition (Carey 2017). Additionally, recent studies have shown sensitivity to the approved BCL2 inhibitor venetoclax in AML associates with undifferentiated leukemic cells (Pei 2020; Zhang 2018; Majumder 2020). Based on these associations, we evaluated the combination of doramapimod (DORA), a p38 MAPK inhibitor, with venetoclax (VEN) for potential enhanced sensitivity on primary AML cells. Ex vivo drug screening of primary AML patient samples (n=335) revealed significantly enhanced efficacy of VEN+DORA compared to either single agent (Nemenyi test; p&lt;0.0001). This broad sensitivity of the VEN+DORA combination was not significantly associated with an array of clinical, genetic, and mutational features in the patient samples tested, in contrast to single agents, particularly VEN. Analysis of blood cell differential counts of patient samples tested identified increased monocyte levels were significantly correlated with sensitivity to DORA and resistance to VEN as single agents (Spearman r = -0.3 and 0.6; p&lt;0.0001), associations that were not apparent with the combination. For patient samples with accompanying FAB differentiation state-based designations (n=108), sensitivities of the combination were similar across classifications of undifferentiated (M0/M1) through monocytic (M4/M5) acute leukemia. In contrast, single-agent VEN was significantly more sensitive in undifferentiated compared to monocytic specimens, whereas DORA sensitivity showed the reverse trend (though to a lesser degree). These differences in sensitivity were further validated by immunophenotyping data where available (n=105), which showed surface markers associated with resistance to VEN (CD11b, CD14, CD16, CD56, CD64, HLADR; Wilcoxon Rank Sum, p&lt;0.001 to p=0.007) or sensitivity to VEN (CD117; p=0.001) or DORA (CD14; HLADR; p=0.004). By contrast, none of these associations significantly distinguished sensitivity for the VEN+DORA combination. Expression levels of MAPK14 and BCL2, the respective primary targets of DORA and VEN, were concordant with their respective drug sensitivities associated with FAB classification; that is, significantly higher levels of BCL2 in M0/M1 leukemias and MAPK14 in M4/M5 cases (Mann-Whitney test; p&lt;0.0001; n=145). Further dissection of transcriptomic and drug sensitivity data revealed strong correlation and gene set enrichment for DORA and VEN sensitivities with monocyte-like and progenitor-like signatures, respectively (n=225), for cell differentiation states previously described for AML (van Galen 2019), and these associations diminished for the combination treatment. Lastly, the VEN+DORA combination enhanced efficacy and synergistic inhibition was confirmed using human AML cell line models tested with a matrix of potential dose concentrations. Taken together, these findings suggest that exploiting distinct, complementary sensitivity profiles of targeted therapies with respect to leukemic differentiation state, such as dual targeting of p38 MAPK and BCL2, offers an opportunity for broad, enhanced efficacy across the clinically challenging heterogeneous landscape of AML. Disclosures Druker: Novartis Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Recludix Pharma, Inc.: Consultancy; EnLiven: Consultancy, Research Funding; Pfizer: Research Funding; The RUNX1 Research Program: Membership on an entity's Board of Directors or advisory committees; Merck & Co: Patents & Royalties; Aileron: Membership on an entity's Board of Directors or advisory committees; ALLCRON: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Aptose Therapeutics: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Blueprint Medicines: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Research Funding; Cepheid: Consultancy, Membership on an entity's Board of Directors or advisory committees; GRAIL: Current equity holder in publicly-traded company; VB Therapeutics: Membership on an entity's Board of Directors or advisory committees; Iterion Therapeutics: Membership on an entity's Board of Directors or advisory committees; Nemucore Medical Innovations, Inc.: Consultancy; Third Coast Therapeutics: Membership on an entity's Board of Directors or advisory committees; Vincerx Pharma: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees. Tyner: Genentech: Research Funding; Takeda: Research Funding; Astrazeneca: Research Funding; Constellation: Research Funding; Agios: Research Funding; Petra: Research Funding; Incyte: Research Funding; Array: Research Funding; Gilead: Research Funding; Janssen: Research Funding; Seattle Genetics: Research Funding; Schrodinger: Research Funding.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4509-4509 ◽  
Author(s):  
R. Frank Cornell ◽  
Adriana C Rossi ◽  
Rachid Baz ◽  
Craig C Hofmeister ◽  
Chaim Shustik ◽  
...  

Abstract Introduction - Inhibition of Exportin 1 (XPO1) is a novel treatment approach for multiple myeloma (MM). XPO1 mediates the nuclear export of cell-cycle regulators and tumor suppressor proteins leading to their functional inactivation. In addition, XPO1 promotes the export and translation of the mRNA of key oncoproteins (e.g. c-MYC, BCL-2, Cyclin D). XPO1 overexpression occurs in solid and hematological malignancies, including MM and is essential for MM cell survival. Selinexor, the first oral SINE compound, has shown promising anti-MM activity in phase 1 studies but has been associated with gastrointestinal and constitutional toxicities including nausea, anorexia and fatigue. KPT-8602 is a second generation oral SINE compound with similar in vitro potency to selinexor, however, has substantially reduced brain penetration compared with selinexor, and demonstrated markedly improved tolerability with minimal anorexia and weight loss in preclinical toxicology studies. In murine models of MM, KPT-8602 can be dosed daily (QDx5) with minimal anorexia and weight loss. We have therefore initiated a phase 1/2 first-in-human clinical trial. Methods - This phase 1/2 clinical trial was designed to evaluate KPT-8602 as a single agent and in combination with low dose dexamethasone (dex) in patients (pts) with relapsed / refractory MM (RRMM). KPT-8602 is dosed orally (QDx5) for a 28-day cycle with a starting dose of 5 mg. Low dose dex (20 mg, twice weekly) is allowed after cycle 1 if at least a minimal response (MR) is not observed. The primary objective is to evaluate the safety and tolerability including dose-limiting toxicity (DLT), determine the maximum tolerated dose (MTD), the recommended Phase 2 dose (RP2D), and evidence for anti-MM activity for KPT-8602 single agent and in combination with dex. The pharmacokinetic (PK) and pharmacodynamic (PDn; XPO1 mRNA) profile of KPT-8602 will also be determined. PDn predictive biomarker analysis and ex vivo drug response assays are underway using tumor cells from bone marrow aspirates before treatment, during and at relapse. These analyses include cell death pathway assays by flow and nuclear/cytoplasmic localization of XPO1, NF-ƙB, IƙBα, IKKα, NRIF and p53 by imaging flow and IHC. Results - As of 01-Aug-2016, 6 pts 2 M/4 F, (median of 6 prior treatment regimens, median age of 71) with RRMM have been enrolled. Common related grade 1/2 adverse events (AEs) include thrombocytopenia (3 pts), nausea (2 pts) and diarrhea (2 pts). Grade 3 AEs include neutropenia (1 pt) and dehydration (1 pt). No grade 4 or 5 AEs have been reported. No DLTs have been observed and the MTD has not been reached. 5 pts were evaluable for responses (1 pt pending evaluation): 1 partial response, 1 minimal response, and 3 stable disease; no pts have progressed on therapy with the longest on for >5 months. The PK properties following oral administration showed that 5 mg of KPT-8602 was rapidly absorbed (mean tmax= 1 hr, mean Cmax= 30.6 ng/mL). The mean AUCinf was calculated to be 141 ng•hr/mL. After tmax, KPT-8602 declined at an estimated mean t½ of 4 hr. At the same dose level, XPO1 mRNA expression was the highest (~2.5 fold) at 8 hr post dose. Conclusions - Oral KPT-8602 is well tolerated in heavily pretreated pts with RRMM. Gastrointestinal and constitutional toxicities observed with twice weekly selinexor have not been observed with 5x/week KPT-8602, including in pts on study for >4 months. PK was predictable and in line with selinexor. These early results show encouraging disease control with pts remaining on therapy. Enrollment is on-going. Disclosures Rossi: Takeda: Speakers Bureau; Janssen: Speakers Bureau; Onyx: Research Funding, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. Baz:Takeda/Millennium: Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Research Funding; Signal Genetics: Research Funding; Bristol-Myers Squibb: Research Funding; Merck: Research Funding; Novartis: Research Funding. Hofmeister:Karyopharm Therapeutics: Research Funding; Arno Therapeutics, Inc.: Research Funding; Signal Genetics, Inc.: Membership on an entity's Board of Directors or advisory committees; Janssen: Pharmaceutical Companies of Johnson & Johnson: Research Funding; Incyte, Corp: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Takeda Pharmaceutical Company: Research Funding; Teva: Membership on an entity's Board of Directors or advisory committees. Shustik:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: 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; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Richter:Amgen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Jannsen: Speakers Bureau. Chen:Janssen: Honoraria, Research Funding; Takeda: Research Funding; Celgene: Honoraria, Research Funding. Vogl:Takeda: Consultancy, Research Funding; Celgene: Consultancy; GSK: Research Funding; Calithera: Research Funding; Teva: Consultancy; Karyopharm: Consultancy; Acetylon: Research Funding; Constellation: Research Funding. Shacham:Karyopharm Therapeutics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Baloglu:Karyopharm Therapeutics: Employment, Equity Ownership. Senapedis:Karyopharm Therapeutics: Employment, Equity Ownership. Ellis:Karyopharm Therapeutics: Employment, Equity Ownership. Friedlander:Karyopharm Therapeutics: Employment. Choe-Juliak:Karyopharm Therapeutics: Employment. Sullivan:Karyopharm Therapeutics: Research Funding. Kauffman:Karyopharm Therapeutics Inc: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1901-1901
Author(s):  
Despina Bazou ◽  
Muntasir M Majumder ◽  
Ciara Tierney ◽  
Sinead O'Rourke ◽  
Pekka Anttila ◽  
...  

Abstract Introduction: A hallmark of Multiple Myeloma (MM) is the sequel development of drug resistant phenotypes, which may be present initially or emerge during the course of treatment. These drug resistant phenotypes reflect the intra-tumor and inter-patient heterogeneity of this cancer. Most MM cells are sensitive to proteasome inhibitors (PIs), which have become the standard of care in the treatment of newly diagnosed and relapsed MM. However, resistance develops (intrinsic/acquired). Although several novel drugs have recently been approved or are in development for MM, there are few molecular indicators to guide treatment selection. To address this limitation we have combined mass spectrometry-based proteomics analysis together with ex vivo drug response profiles and clinical outcome to elucidate a best possible accurate phenotype of the resistant sub-clones, thus yielding a theranostic profile that will inform therapeutic and drug development strategies. Methods: We performed mass spectrometry-based proteomics analysis on plasma cells isolated from 38 adult MM patient bone marrow aspirates (CD138+). Samples were obtained at diagnosis or prior to commencing therapy. The participating subjects gave written informed consent in accordance with the Declaration of Helsinki that was approved by local ethics committees. For the proteomics analysis, peptides were purified using the filtered aided sample preparation (FASP) method. Subsequently, samples were prepared for label-free liquid chromatography mass spectrometry (LC-MS/MS) using a Thermo Scientific Q-Exactive MS mass spectrometer. Proteins were analysed using the MaxQuant and Perseus software for mass-spectrometry (MS)-based proteomics data analysis, UniProtKB-Swiss Prot database and KEGG Pathway database. In parallel, we undertook a comprehensive functional strategy to directly determine the drug dependency of myeloma plasma cells based on ex vivo drug sensitivity and resistance testing (DSRT)as previously described (1). Results: Our initial proteomic analysis was generated by examining MM patient plasma cells, grouped based on DSRT to 142 anticancer drugs including standard of care and investigational drugs. Each of the 142 drugs was tested over a 10,000-fold concentration range, allowing for the establishment of accurate dose-response curves for each drug in each patient. MM patients were stratified into four distinct subgroups as follows: highly sensitive (Group I), sensitive (Group II), resistant (Group III) or highly resistant (Group IV) to the panel of drugs tested. We then performed blinded analysis on the 4 groups of CD138+ plasma cells divided based on the ex vivo sensitivity profile, identifying a highly significant differential proteomic signature between the 4-chemosensitivity profiles, with Cell Adhesion Mediated-Drug Resistance (CAM-DR) related proteins (e.g. integrins αIIb and β3) significantly elevated in the highly resistant phenotype (Group IV). In addition our results showed that Group I patients displayed significant upregulation of cell proliferation proteins including: MCM2, FEN1, PCNA and RRM2. Furthermore, Group I patients have shorter Progression Free Survival (PFS) as well as Overall Survival (OS) compared to the other subgroups. Figure 1 shows the Heatmap summarizing the expression of proteins (log2 fold change) in the four distinct MM patient subgroups. Conclusions:Our findings suggest that combining a proteomics based study together with drug sensitivity and resistance testing allows for an iterative adjustment of therapies for patients with MM, one patient at a time, thus providing a theranostic approach. Our results suggest that the disease driving mechanisms in the patient subgroups are distinct, with highly resistant patients exhibiting cell adhesion mediated cytoprotection, while highly sensitive patients show an increased cell proliferation protein profile with shorter PFS and OS. Our study aims to guide treatment decisions for individual cancer patients coupled with monitoring of subsequent responses in patients to measure and understand the efficacy and mechanism of action of the drugs. Future work will include the establishment of flow cytometry-based screening assays to identify the different resistant phenotypes at diagnosis/relapse. References: (1) M. M. Majumder et al., Oncotarget 8(34), 56338 (2017) Disclosures Anttila: Amgen: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Silvennoinen:Amgen: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; BMS: Honoraria, Research Funding. Heckman:Orion Pharma: Research Funding; Celgene: Research Funding; Novartis: Research Funding.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 292-292 ◽  
Author(s):  
Alan F List ◽  
Kathy Rocha ◽  
Ling Zhang ◽  
Rami S. Komrokji ◽  
Justine Clark ◽  
...  

Abstract Abstract 292 Background: Allelic deficiency for the RPS14 gene impairs differentiation and survival of erythroid progenitors in del(5q) MDS (Nature 2008; 451:335). Nucleolar stress arising from disruption of ribosome assembly fosters MDM2 sequestration by free ribosome components resulting in p53 stabilization and erythroid hypoplasia (Nat Cell Biol 2009; 11:501). We recently reported that reduced gene dosage of the lenalidomide (LEN) inhibitable, haplodeficient phosphatases CDC25C and PP2Acα is a key determinant of drug sensitivity in del(5q) MDS (PNAS 2009; 106: 12974). We now show that shRNA suppression of these genes to levels commensurate with haplodeficiency reinforces p53 accumulation, and that treatment with LEN promotes MDM2-mediated p53 degradation to transition del(5q) clones to G2/M arrest. We hypothesized that emergence of resistance to LEN in del(5q) MDS arises from two possible mechanisms: (1) up-regulation of haplodeficient drug targets or compensatory isotypes, or (2) inactivating mutations of the TP53 or CDC25C genes. Methods: To investigate mechanisms of LEN resistance, we studied sequential bone marrow (BM) specimens obtained at baseline (BL), response to treatment (TR) and treatment failure (TF) from 12 LEN treated patients with Low/INT-1 risk, transfusion-dependent del(5q) MDS. Eleven patients achieved clonal suppression and transfusion independence; 7 patients developed clinical drug resistance with primary clonal recovery. Immunohistochemical (IHC) staining for cdc25-C, -A and -B; PP2A–Ca and p53 were performed using a biotin-streptavidin-horseradish peroxidase method and compared to 6 age-matched controls; intensity of cytoplasmic or nuclear staining in hematopoietic elements was recorded after blinded review. DNA and RNA were extracted from cryopreserved BM mononuclear cells (BM-MNC) or fixed paraffin blocks from BM clot and biopsy sections. Expression of CDC25C splice variants was assessed by RT-PCR and total gene expression by real time (QT)-PCR. Exonic DNA encoding the catalytic [exons 8–14] and nuclear export domains [exon 11] of CDC25C and the DNA-binding domain of TP53 [exons 4–9] was sequenced for gene mutation analysis. Differences in mean values were compared by paired t-test. Results: P53 immunostaining was significantly higher in del(5q) BL specimens compared to controls ( relative expression [RE] 9.6 vs. 0.25; P =0.007). An admixture of nuclear and cytoplasmic staining for p53 and each cdc25 isotype was observed at BL that was largely restricted to erythroid precursors, whereas at TR cdc25-C and -A expression was primarily cytoplasmic, consistent with drug-induced nuclear exclusion. At TR, RE of only cdc25C (BL, 75 vs. TR, 49; P=0.05) and PP2A (29.2 vs. 12.3; P=0.025) was significantly reduced; whereas at TF cdc25C (TR, 43 vs. TF, 166; P=0.003), cdc25A (42.4 vs. 150; P=0.006), PP2A (7.3 vs. 65.6; P=0.028) and p53 (0.92 vs. 25.4; P=0.024) RE significantly increased. Nuclear localization of cdc25C and p53 but not cdc25A predominated at TF, consistent with escape from cdc25C inhibition. QT-PCR confirmed transcriptional up-regulation of CDC25C at TF with a mean 8.8-fold increase in gene expression vs. BL. DNA sequencing revealed no acquisition of somatic mutations within the CDC25C and TP53 exons studied [n=5]. Conclusions: Secondary resistance to LEN in del(5q) MDS is associated with over-expression and activation of the haplodeficient drug-inhibitable phosphatases, cdc25C and PP2A, with consequent restoration of wt-p53 activation. Absence of gene mutations within the coding exons analyzed suggests that transcriptional compensation alone is responsible for drug resistance. Novel agents targeting transcriptional repression of CDC25C may restore LEN sensitivity and merit investigation in drug resistant del(5q) MDS. Disclosures: List: Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Komrokji:Celgene: Research Funding, Speakers Bureau. Lancet:Celgene: Research Funding. Maciejewski:Esai: Membership on an entity's Board of Directors or advisory committees; Celgene: Speakers Bureau. Sekeres:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3950-3950
Author(s):  
Christopher A. Eide ◽  
Stephen E Kurtz ◽  
Andy Kaempf ◽  
Nicola Long ◽  
Jessica Leonard ◽  
...  

Background: In patients with acute lymphoblastic leukemia (ALL), patient outcomes vary considerably by patient age group, specific genetic subtypes, and treatment regimen. Large-scale sequencing efforts have uncovered a spectrum of mutations and gene fusions in ALL, suggesting that combinations of agents will be required to treat these diseases effectively. Previous preclinical studies have shown efficacy of the BCL2 inhibitor venetoclax alone or in combination in ALL cells (Chonghaile et al., Can Disc 2014; Leonard et al, STM 2018), and the multi-kinase inhibitor ibrutinib (approved for patients with chonic lymphoblastic leukemia (CLL)) has also shown potent activity in subsets of ALL (Kim et al., Blood 2017). However, the combination of ibrutinib and venetoclax has not been evaluated to date in patients with ALL. Methods: We used a functional ex vivo screening assay to evaluate the potential efficacy of the combination of ibrutinib and venetoclax (IBR+VEN) across a large cohort (n=808) of patient specimens representing a broad range of hematologic malignancies. Primary mononuclear cells isolated from leukemia patients were plated in the presence of graded concentrations of venetoclax, ibrutinib, or the combination of both FDA-approved drugs. IC50 and AUC values were derived from probit-based regression for each response curve. A panel of clinical labs, treatment information, and genetic features for tested ALL patient specimens was collated from chart review. Single and combination drug treatment sensitivity were compared within groups by Friedman test, across groups by Mann-Whitney test, and with continuous variables by Spearman rank correlation. Results: Consistent with clinical data and previous literature, IBR+VEN was highly effective in CLL specimens ex vivo (median IC50=0.015 µM). Intriguingly, among specimens from 100 unique ALL patients, we also observed that IBR+VEN demonstrated significantly enhanced efficacy by AUC and IC50 compared to either single agent (p<0.001; median IC50=0.018 µM). In contrast, evaluation of this combination on primary mononuclear cells from two healthy donors showed little to no sensitivity. Breakdown of combination sensitivity (as measured by AUC) by a variety of clinical and genetic features revealed no associations with gender or specimen type. Among continuous variables tested, age was modestly correlated with combination AUC (Spearman r = 0.26) and increased blasts in the bone marrow were associated with increased sensitivity to the combination (Spearman r = -0.41; p = 0.0068). More broadly, specimens from patients with B-cell precursor disease (B-ALL) were more sensitive to IBR+VEN than those with T-cell precursor leukemia (T-ALL) (p = 0.0063). Within the B-ALL patient samples, those harboring the BCR-ABL1 fusion were significantly less sensitive to IBR+VEN than other subtypes of B-ALL (p = 0.0031). Within the T-ALL subset, there was a trend toward reduced sensitivity in patients with evidence of mutations in NOTCH1, though statistical significance was not reached. Evaluation of the combination using an expanded 7x7 concentration matrix in human ALL cell lines revealed varying degrees of sensitivity. For example, IBR+VEN showed enhanced efficacy in RCH-ACV B-ALL cells and showed synergy for the majority of drug-pair concentrations by the highest single agent (HSA) method (ibrutinib, venetoclax, and combination IC50: 0.60, 3.4, and 0.28 uM, respectively). Conclusion: Our findings suggest that the IBR+VEN combination, currently approved for patients with CLL, also demonstrates impressive efficacy against primary leukemia cells from ALL patients, warranting further investigation as a treatment strategy in the clinic to continue to improve outcomes for patients. Disclosures Leonard: Amgen: Research Funding. Druker:Cepheid: Consultancy, Honoraria; Pfizer: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Research Funding; Merck & Co: Patents & Royalties: Dana-Farber Cancer Institute license #2063, Monoclonal antiphosphotyrosine antibody 4G10, exclusive commercial license to Merck & Co; Dana-Farber Cancer Institute (antibody royalty): Patents & Royalties: #2524, antibody royalty; OHSU (licensing fees): Patents & Royalties: #2573, Constructs and cell lines harboring various mutations in TNK2 and PTPN11, licensing fees ; Gilead Sciences: Other: former member of Scientific Advisory Board; Beta Cat: Membership on an entity's Board of Directors or advisory committees, Other: Stock options; Aptose Biosciences: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Amgen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; ALLCRON: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Patents & Royalties, Research Funding; Pfizer: Research Funding; Aileron Therapeutics: #2573, Constructs and cell lines harboring various mutations in TNK2 and PTPN11, licensing fees , Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Research Funding; Novartis: Other: PI or co-investigator on clinical trial(s) funded via contract with OHSU., Patents & Royalties: Patent 6958335, Treatment of Gastrointestinal Stromal Tumors, exclusively licensed to Novartis, Research Funding; GRAIL: Equity Ownership, Other: former member of Scientific Advisory Board; Patient True Talk: Consultancy; The RUNX1 Research Program: Membership on an entity's Board of Directors or advisory committees; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees, Other: Stock options; Beat AML LLC: Other: Service on joint steering committee; CureOne: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; ICON: Other: Scientific Founder of Molecular MD, which was acquired by ICON in Feb. 2019; Monojul: Other: former consultant; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Burroughs Wellcome Fund: Membership on an entity's Board of Directors or advisory committees. Tyner:Petra: Research Funding; Agios: Research Funding; Array: Research Funding; Gilead: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Syros: Research Funding; Takeda: Research Funding; Seattle Genetics: Research Funding; AstraZeneca: Research Funding; Seattle Genetics: Research Funding; Array: Research Funding; Aptose: Research Funding; Incyte: Research Funding; Syros: Research Funding; Takeda: Research Funding; Petra: Research Funding; Agios: Research Funding; Constellation: Research Funding; Aptose: Research Funding; Gilead: Research Funding; Incyte: Research Funding; AstraZeneca: Research Funding; Constellation: Research Funding; Janssen: Research Funding; Genentech: Research Funding.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3291-3291
Author(s):  
Ariosto Silva ◽  
Maria Silva ◽  
Timothy Jacobson ◽  
Mark B Meads ◽  
Allison Distler ◽  
...  

Abstract Introduction: Multiple myeloma is a heterogeneous plasma cell neoplasm that remains all but incurable despite significant advances in treatment. We anticipate that the ability to overcome this hurdle resides in personalized strategies designed to specifically recognize, target, and anticipate dynamic tumor subpopulations with variable drug response profiles within an individual. To this end, we have developed a novel multi-disciplinary approach using organotypic drug screening and mathematical modeling to assess drug sensitivity of the different subpopulations within the tumor burden of individual patients and, in turn, provide accurate predictions of clinical outcome to anti-myeloma therapy. Material and methods: We have used a novel combination of ex vivo drug sensitivity assay and mathematical models to predict clinical response of 48 MM patients (11 newly diagnosed and 37 relapsed, 18 females and 30 males, median age 64.5, range 45-77) treated with a combination of proteasome inhibitors and IMIDs (37), nuclear export and topo2 isomerase inhibitors (10), and high dose melphalan (1). MM cells (CD138+) were extracted from fresh bone marrow aspirates and seeded in an ex vivo co-culture model with human stroma in 384-well plates. These cells were exposed to a number of chemotherapeutic and experimental agents (up to 31) for a period of 4 days, during which viability was assessed continuously using bright field imaging and digital image analysis. A mathematical model was used to interpolate the dose response dynamics to each drug, and combined with drug and regimen-specific pharmacokinetic data, generate predictions of clinical response to each individual drug. We have then validated ex vivo-based predictions with actual outcome 90 days post-biopsy. In patients treated with combinations, the mathematical model combined the effect of each single drug assuming additivity. Results: To examine the accuracy of the predicted in silico responses, we have assessed the model according to three increasingly strict standards of accuracy: (A) The model correctly predicted 32 out of 32 responders (100%) and 14 out of 16 non-responders (88%), with an overall accuracy of 96%; (B) According to IMWG stratification, the model correctly stratified 14 out of 16 patients as stable or progressive disease (PD/SD, 88%, the remaining 2 incorrectly predicted as MR/PR), 15 our of 18 as minimal or partial response (MR/PR, 83%, the remaining 3 incorrectly predicted as VGPR/CR), and 10 out of 14 patients as very good partial response or complete response (71%, the remaining 4 incorrectly classified as MR/PR), with an overall accuracy of 81%; (C) The 48 patients from this study provided a total of 120 measures of tumor burden (M-spike or SFLC) within the 90-day post-biopsy period. The direct correlation between tumor burden measures and model predictions led to a Pearson r=0.5547 (P<0.0001) and the correlation line [Actual]=0.8282*[Model]+16.27, where [Model] and [Actual] are the predicted and actual tumor burdens as a percentage of tumor burden measure at the moment of treatment initiation. From the 14 non-responders, the model predicted that 2 would have had a VGPR/CR and 3 would have had a MR/PR if treated with drugs differing from those given clinically. Intriguingly, from the 13 patients who received 3-agent therapies with matched in silico drug testing, only 2 had response to all agents, 6 had a response to 2 agents, 4 responded to only 1 of the 3 agents and 1 responded to none of the agents. Next, we examined the 18 patients with a 2-drug match between in silico and actual treatment. From these, 1 patient model responded to 2 drugs, 12 responded to only 1 drug, and 5 responded to none. From the 17 patients with a single agent match between treatment and in silico, 8 had a response and 9 had no response. In summary, among the drugs tested both ex vivoand actually administered to patients, 48% had some predicted clinical benefit, while 52% of agents had none, and could theoretically be removed without affecting clinical outcome. Conclusion: We observed an excellent correlation between in silicopredicted and clinically observed responses in 48 MM patient specimens. Our data suggest that this model may provide critical insight in the selection the appropriate therapeutic agents and number of agents to combine for a given individual. Further validation is required to better define the role of this approach as a clinical decision support tool. Figure Figure. Disclosures Baz: Novartis: Research Funding; Signal Genetics: Research Funding; Karyopharm: Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda/Millennium: Research Funding; Bristol-Myers Squibb: Research Funding; Merck: Research Funding. Shain:Signal Genetics: Research Funding; Takeda/Millennium: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen/Onyx: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Speakers Bureau.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1541-1541
Author(s):  
Jeffrey W. Tyner ◽  
Brian J. Druker ◽  
Cristina E. Tognon ◽  
Stephen E Kurtz ◽  
Leylah M. Drusbosky ◽  
...  

Abstract Background: New prognostic factors have been recently identified in AML patient population that include frequent mutations of receptor tyrosine kinases (RTK) including KIT, PDGFR, FLT3, that are associated with higher risk of relapse. Thus, targeting RTKs could improve the therapeutic outcome in AML patients. Aim: To create a digital drug model for dasatinib and validate the predicted response in AML patient samples with ex vivo drug sensitivity testing. Methods: The Beat AML project (supported by the Leukemia & Lymphoma Society) collects clinical data and bone marrow specimens from AML patients. Bone marrow samples are analyzed by conventional cytogenetics, whole-exome sequencing, RNA-seq, and an ex vivo drug sensitivity assay. For 50 randomly chosen patients, every available genomic abnormality was inputted into a computational biology program (Cell Works Group Inc.) that uses PubMed and other online resources to generate patient-specific protein network maps of activated and inactivated pathways. Digital drug simulations with dasatinib were conducted by quantitatively measuring drug effect on a composite AML disease inhibition score (DIS) (i.e., cell proliferation, viability, and apoptosis). Drug response was determined based on a DIS threshold reduction of > 65%. Computational predictions of drug response were compared to dasatinib IC50 values from the Beat AML ex vivo testing. Results: 23/50 (46%) AML patients had somatic mutations in an RTK gene (KIT, PDGFR, FLT3 (ITD (n=15) & TKD (n=4)), while 27/50 (54%) were wild type (WT) for the RTK genes. Dasatinib showed ex vivo cytotoxicity in 9/50 (18%) AML patients and was predicted by CBM to remit AML in 9/50 AML patients with 4 true responders and 5 false positive. Ex vivo dasatinib responses were correctly matched to the CBM prediction in 40/50 (80%) of patients (Table1), with 10 mismatches due to lack of sufficient genomic information resulting in profile creation issues and absence of sensitive loops in the profile. Only 4/23 (17%) RTK-mutant patients and 5/27(19%) RTK-WT patients were sensitive to dasatinib ex vivo, indicating that presence of somatic RTK gene mutations may not be essential for leukemia regression in response to dasatinib. Co-occurrence of mutations in NRAS, KRAS and NF1 seemed to associate with resistance as seen in 10 of the 14 profiles harboring these mutations. Conclusion: Computational biology modeling can be used to simulate dasatinib drug response in AML with high accuracy to ex vivo chemosensitivity. DNA mutations in RTK genes may not be required for dasatinib response in AML. Co-occurrence of NRAS, KRAS and NF1gene mutations may be important co-factors in modulating response to dasatinib. Disclosures Tyner: Leap Oncology: Equity Ownership; Syros: Research Funding; Seattle Genetics: Research Funding; Janssen: Research Funding; Incyte: Research Funding; Gilead: Research Funding; Genentech: Research Funding; AstraZeneca: Research Funding; Aptose: Research Funding; Takeda: Research Funding; Agios: Research Funding. Druker:Third Coast Therapeutics: Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals: Research Funding; Millipore: Patents & Royalties; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees; Oregon Health & Science University: Patents & Royalties; McGraw Hill: Patents & Royalties; Celgene: Consultancy; MolecularMD: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; GRAIL: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Meyers Squibb: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; Aptose Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Henry Stewart Talks: Patents & Royalties; Patient True Talk: Consultancy; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; ARIAD: Research Funding; Fred Hutchinson Cancer Research Center: Research Funding; Beta Cat: Membership on an entity's Board of Directors or advisory committees; Cepheid: Consultancy, Membership on an entity's Board of Directors or advisory committees; Leukemia & Lymphoma Society: Membership on an entity's Board of Directors or advisory committees, Research Funding; ALLCRON: Consultancy, Membership on an entity's Board of Directors or advisory committees; Aileron Therapeutics: Consultancy; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; Monojul: Consultancy. Sahu:Cellworks Research India Private Limited: Employment. Vidva:Cellworks Research India Private Limited: Employment. Kapoor:Cellworks Research India Private Limited: Employment. Azam:Cellworks Research India Private Limited: Employment. Kumar:Cellworks Research India Private Limited: Employment. Chickdipatti:Cellworks Research India Private Limited: Employment. Raveendaran:Cellworks Research India Private Limited: Employment. Gopi:Cellworks Research India Private Limited: Employment. Abbasi:Cell Works Group Inc.: Employment. Vali:Cell Works Group Inc.: Employment. Cogle:Celgene: Other: Steering Committee Member of Connect MDS/AML Registry.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 12-13
Author(s):  
Reinaldo Dal Bello Figueiras ◽  
Justine Pasanisi ◽  
Romane Joudinaud ◽  
Matthieu Duchmann ◽  
Gaetano Sodaro ◽  
...  

Context. Functional precision medicine is gaining momentum in AML, notably through ex vivo drug sensitivity screening (DSS) of primary patient (pt) cells (Pemovska Cancer Discov 2013, Tyner Nature 2018). The DSS landscape differs across genetic AML subgroups (Tyner Nature 2016), of which NPM1mut is the most frequent (Papaemmanuil NEJM 2016). DSS in AML has mostly been done in standard conditions, with overall viability as unique endpoint. Niche signals, which can be partly mimicked in vitro, convey drug resistance in vivo. Drugs can induce a variety of cell fates in AML. Induction of differentiation rather than killing of blasts, can result in false negative results in global viability assays. Persistence of leukemic stem cells (LSC) represents a major cause of treatment failure. GPR56 is a ubiquitous surface marker enriching for LSCs and stable upon short-term ex vivo culture (Pabst Blood 2016). Objectives. To develop an ex vivo niche-like multiparametric DSS platform for primary AML cells. To validate its clinical relevance in NPM1mut pts treated with conventional DNR-AraC chemotherapy. To discover new sensitizers to DNR-AraC chemotherapy in NPM1mut AML. Results. We designed an MFC panel to count viable blasts and measure their differentiation (CD11b/CD14/CD15) and stemness (GPR56) after exclusion of residual lymphocytes (Figure 1A). We validated GPR56 expression as stemness marker based on increased retention of GPR56+ cells in niche-like coculture combining hypoxia (O2 3%) and MSC compared to standard conditions (p&lt;0.0001, Figure 1B) and limit dilution assays of residual GPR56+ cells at 72h of niche-like culture in 3 NPM1mut AMLs (Figure 1C). Using a limited panel of 14 drugs or combinations at fixed concentrations, our MFC readout after 72h of coculture with MSC+hypoxia revealed the distinct mode of action of different agents or combinations including the differentiation activity of ATO-ATRA, the LSC-sparring cytotoxicity of DNR-AraC and the anti-LSC- activity of VEN (Figure 1D). To further mimic in vivo conditions, we derived a MEMa-based plasma-like medium (PLM) based on targeted metabolomics (Figure 1E) and electro-chemoluminescent cytokine assays of 29 diagnostic AML bone marrow plasma samples compared to conditioned media of primary AML cells cultured in niche-like conditions (MSC, hypoxia). This instructed the design of our custom PLM with dialyzed FBS and defined low-dose (~1 ng/mL range) cytokines (CK) and amino-acid (AA) concentrations. We next investigated the contribution of MSCs, hypoxia, plasma-like AAs and CKs on blasts viability, differentiation, stemness and drug response in 3 NPM1mut AMLs exposed to fixed concentrations of 6 core AML therapies. This analysis uncovered significant interactions between these 4 niche components in dictating blast viability and stemness upon 72h ex vivo culture (Figure 1F) and revealed the distinct contribution of these niche components to drug sensitivity. RNA-seq of primary blasts cultured in niche-like, plasma-like conditions revealed marked enrichment of stemness pathways compared to ex vivo culture in standard conditions. Finally, we explored DNR-AraC (five-point serial dilution) alone or in combination with fixed, clinically relevant concentrations of 24 drugs in 49 primary AML samples (including 34 NPM1mut). Using AUCs of DNR-AraC on lymphocytes as internal control, we first validated our NEXT assay on NPM1 MRD levels in the 34 NPM1mut pts treated frontline with conventional DNR-AraC regimens (Figure 1G). Across all 49 pts, we uncovered 11 different optimal 'third-drugs', stressing the role of our NEXT assay to deploy precision medicine in daily practice. At the population level, we could nominate 3 top combinations, two of which are currently in clinical investigation (Venetoclax and Selinexor). The unpublished sensitizing effect of low dose (0.25µM) Ruxolitinib on DNR-AraC uncovered with our NEXT assay is currently being investigated in PDX models. Conclusion. We designed the NEXT assay, a multiparametric drug screening of AML viability, differentiation and stemness in niche-like culture combining hypoxia, stromal interactions and plasma-like medium. Components of the niche-like culture interact to govern leukemic viability and stemness. Our assay could predict MRD achievement in NPM1mut AML and identifies novel sensitizers to DNR-AraC in these pts. Disclosures Clappier: Amgen: Honoraria, Research Funding. Ades:Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; jazz: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Research Funding; novartis: Research Funding; Celgene/BMS: Research Funding. Itzykson:Amgen: Membership on an entity's Board of Directors or advisory committees; Otsuka Pharma: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Stemline: Membership on an entity's Board of Directors or advisory committees; Oncoethix (now Merck): Research Funding; Janssen: Research Funding; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria; Daiichi Sankyo: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS (Celgene): Honoraria; Sanofi: Honoraria; Astellas: Honoraria.


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