Genotype-Phenotype Relationships and Therapeutic Targets in Acute Erythroid Leukemia

Background: Acute erythroid leukemia (AEL) is a rare subtype of AML characterized by erythroid predominant proliferation and classified into two subtypes with pure erythroid (PEL) and myeloid/erythroid (MEL) phenotypes. Although gene mutations in AEL have been described in several reports, genotype phenotype correlations are not fully understood with little knowledge about the feasible molecular targets for therapy. Methods: To understand the mechanism of the erythroid dominant phenotype of AEL and identify potential therapeutic targets for AEL, we analyzed a total of 105 AEL cases with the median age of 60 (23-86), using targeted-capture sequencing of commonly mutated genes in myeloid neoplasms, together with 1,279 SNPs for copy number measurements. Among these 105 cases, 13 were also analyzed by RNA sequencing. Genetic profiles of these 105 AEL cases were compared to those of 775 cases with non-erythroid AML (NEL) including 561 cases from The Cancer Genome Atlas and Beat AML study. An immature erythroid cell line (TF1) and three patient-derived xenografts (PDX) established from AEL with JAK2 and/or EPOR amplification. Cell line and samples from patients were inoculated into immune-deficient mice and tested for their response to JAK1/2 inhibitor. Results: According to unique genetic alterations, AEL was classified into 4 subgroups (A-D). Characterized by TP53 mutations and complex karyotype, Group A was the most common subtype and showed very poor prognosis. Remarkably, all PEL cases were categorized into Group A. Conspicuously, 80% of PEL cases had amplifications of JAK2 (6/10; 60%), EPOR (7/10;70%), and ERG (6/10;60%) loci on chromosomes 9p, 19q, and 21q, respectively, frequently in combination, although they were rarely seen in NEL cases. All cases in Group B (n=19, 18%), another prevalent form of AEL, had STAG2 mutations and classified in MEL. To further characterize this subgroup, we compared genetic profiles of STAG2-mutated AEL and NEL. Prominently, 70% (14/20) of STAG2-mutated cases in AEL had KMT2A-PTD, whereas it was found only in 8.8% (3/34) of NEL. CEBPA mutations were also more common in AEL (6/21; 29%) than NEL (4/34; 12%). While Group C was characterized by frequent NPM1 mutations, in contrast to the frequent co-mutation of FLT3 in the corresponding subgroup of NPM1-mutated cases in NEL, NPM1-mutated patents in this subgroup lacked FLT3 mutations but had frequent PTPN11 mutations (8/16; 50%), which were much less common in NEL (25/209; 12%). The remaining cases were categorized into Group D, which was enriched for mutations in ASXL1, BCOR, PHF6, U2AF1 and KMT2C. Recurrent loss-of-function mutations in USP9X were unique to this subtype, although USP9X mutations have been reported in ALL with upregulation of JAK-STAT pathway. In RNA sequencing analysis, AEL cases exhibited gene expression profiles implicated in an upregulated STAT5 signaling pathway, which was seen not only those cases with JAK2 or EPOR amplification, but also those without, suggesting that aberrantly upregulated STAT5 activation might represent a common defect in AEL. Based on this finding, we evaluated the effect of a JAK inhibitior, ruxolitinib, on an AEL-derived cell line and three PDX models established from AEL having TP53 mutations and JAK2 and EPOR mutation/amplification. Of interest, ruxolitinib significantly suppressed cell growth and prolonged overall survival in mice engrafted with TF1 and 2 PDX models with STAT5 downregulation, although the other model was resistant to JAK2 inhibition with persistent STAT5 activation. Conclusion: AEL is a heterogeneous group of AML, of which PEL is characterized by frequent amplifications/mutations in JAK2, EPOR and/or ERG. Frequent involvement of EPOR/JAK/STAT pathway is a common feature of AEL, in which a role of JAK inhibition was suggested. Disclosures Yoda: Chordia Therapeutics Inc.: Research Funding. Shih:Novartis: Research Funding; Celgene: Research Funding; PharmaEssentia: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees. Ishiyama:Alexion: Research Funding; Novartis: Honoraria. Miyazaki:Astellas Pharma Inc.: Honoraria; Sumitomo Dainippon Pharma Co., Ltd.: Honoraria; NIPPON SHINYAKU CO.,LTD.: Honoraria; Celgene: Honoraria; Otsuka Pharmaceutical: Honoraria; Chugai Pharmaceutical Co., Ltd.: Honoraria; Novartis Pharma KK: Honoraria; Kyowa Kirin Co., Ltd.: Honoraria. Nakagawa:Sumitomo Dainippon Pharma Co., Ltd.: Research Funding. Takaori-Kondo:Celgene: Honoraria, Research Funding; Ono Pharmaceutical: Research Funding; Thyas Co. Ltd.: Research Funding; Takeda: Research Funding; CHUGAI: Research Funding; OHARA Pharmaceutical: Research Funding; Sanofi: Research Funding; Novartis Pharma: Honoraria; Bristol-Myers Squibb: Honoraria, Research Funding; Pfizer: Research Funding; Otsuka Pharmaceutical: Research Funding; Eisai: Research Funding; Astellas Pharma: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Nippon Shinyaku: Research Funding; MSD: Honoraria. Kataoka:Asahi Genomics: Current equity holder in private company; Otsuka Pharmaceutical: Research Funding; Takeda Pharmaceutical Company: Research Funding; CHUGAI PHARMACEUTICAL CO., LTD.: Research Funding. Usuki:Alexion: Research Funding, Speakers Bureau; Apellis: Research Funding; Novartis: Research Funding, Speakers Bureau; Chugai: Research Funding. Maciejewski:Novartis, Roche: Consultancy, Honoraria; Alexion, BMS: Speakers Bureau. Ganser:Novartis: Consultancy; Celgene: Consultancy. Thol:Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Ogawa:Sumitomo Dainippon Pharma Co., Ltd.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Research Funding; Asahi Genomics Co., Ltd.: Current equity holder in private company; Eisai Co., Ltd.: Research Funding; Chordia Therapeutics, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; KAN Research Institute, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding. OffLabel Disclosure: Ruxolitinib is used for drug efficacy test using patient-derived xenografts established from acute erythroid leukemia.

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LSD1 Inhibitor CPI-482 Shows Efficacy and Prolongs Survival in Mouse Models of AML and Post-MPN AML in the Context of Constitutive JAK-STAT Pathway Activation

Blood ◽

10.1182/blood-2020-140186 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 50-51

Author(s):

Raajit K. Rampal ◽

John P. McGrath ◽

Aishwarya Krishnan ◽

Bing Li ◽

Wenbin Xiao ◽

...

Keyword(s):

Bone Marrow ◽

Board Of Directors ◽

Cell Lines ◽

Research Funding ◽

Myelogenous Leukemia ◽

Publicly Traded ◽

Private Company ◽

Advisory Committees ◽

Pathway Activation ◽

Stat Pathway

Several novel mechanism-based therapeutic modalities are currently being clinically investigated for the treatment of patients with acute myelogenous leukemia (AML), including agents that exploit genomic vulnerabilities, attenuate leukemia stem cell populations and/or or synergize with anti-leukemic cytotoxic/epigenetic therapies. Lysine-specific demethylase 1 (LSD1) is an enzyme that functions in transcriptional repression by catalyzing the removal of histone H3 lysine 4 methylation, a histone modification associated with transcriptionally competent gene enhancers and transcriptional start sites. Small molecule mediated inhibition of LSD1 alters the chromatin state and the transcriptional output of LSD1 target genes. Transcriptional 'reprogramming' by LSD1 inhibitors either causes a direct impact on cell fate and/or renders malignant cells more susceptible to the treatment with other cancer therapeutic agents. LSD1 inhibitors have shown encouraging phenotypic effects in myelogenous leukemia (AML) models but the key molecular determinants governing LSD1 inhibitor sensitivity remain to be further investigated. Here, we explored the in vitro sensitivity of 350 cancer cell lines to our LSD1 inhibitor CPI-482 to identify potential hyper-responder cell contexts. Four AML cell lines showed high sensitivity with low nanomolar concentration GI50s, each of which contained either a JAK2V617F mutation or a genetic aberration that resulted in JAK-STAT pathway activation. Oral administration of LSD1 inhibitor CPI-482 on a once daily or a once weekly dosing schedule resulted in significant tumor growth inhibition in SET-2 and HEL 92.1.7 JAK2 mutant AML xenograft mouse models. Given the unmet need and poor prognosis in post-MPN secondary AML (sAML) we then explored CPI-482 in a tertiary transplant post-MPN AML retroviral transduction murine model (Jak2V617F retrovirus transduced intoTp53 null bone marrow). Jak2V617F/Tp53 null spleen cells were transplanted into lethally irradiated recipient mice along with wild-type donor support whole bone marrow cells. Mice were randomized to treatment with vehicle, Ruxolitinib (60mg/kg twice daily) or CPI-482 (60mg/kg weekly). Once-weekly treatment with CPI-482 significantly improved survival compared to vehicle (p<0.001) or ruxolitinib (p<0.043) (Figure 1A). Spleen weights were significantly reduced by CPI-482 compared to ruxolitinib (p<0.05;Figure 2B). The white blood cell count was unchanged in mice treated with CPI-482 but increased in both vehicle and ruxolitinib treated mice. Evaluation at the time of terminal take-down of mice demonstrated a significant increase in the proportion of lineage positive cells in both the bone marrow and spleen (compared to vehicle, p<0.05) consistent with restoration of normal hematopoiesis (Figure 1D). Histopathologic evaluation of the spleen demonstrated marked reduction in infiltration by blast cells, restoration of lymphoid follicles, emergence of megakaryocytes (Figure 1E), and modest reductions in reticulin fibrosis in CPI-482 treated mice, which was not observed in ruxolitinib treated mice. Mice tolerated treatment with CPI-482 well, with no changes in weights of treated mice (Figure 1F). Treatment of the JAK2V617F mutant AML cell lines SET-2 and HEL with CPI-482 resulted in specific transcriptional effects, including increased expression of the myeloid differentiation markers LY96 and CD86 and inflammatory response genes. CPI-482 also resulted in upregulation of genes that are repressed by the HOXA9 oncogene in other leukemia contexts. The induction of specific CPI-482 mediated gene expression and phenotypic changes was recapitulated by knockdown of the transcription factor GFI1B, suggesting that, consistent with prior findings in other leukemia contexts, LSD1 functionally cooperates with GFI1B in JAK2V617F mutant AML cells. These data provide support for a potential therapeutic impact of the LSD1 inhibitor CPI-482 in AML and sAML in the context of the JAK2V617F mutation, and thus extend the previous findings that LSD1 inhibitors may have utility in JAK2V617F mutated malignant proliferative neoplasms. Given the pressing need for new therapies for sAML which evolves from a pre-existing MPN, we believe these data form the rationale for a mechanism based clinical trial in this adverse risk myeloid malignancy. Figure Disclosures Rampal: Pharmaessentia: Consultancy; Galecto: Consultancy; Abbvie: Consultancy; Stemline: Consultancy, Research Funding; Constellation: Research Funding; Incyte: Consultancy, Research Funding; Celgene: Consultancy; Promedior: Consultancy; CTI Biopharma: Consultancy; Jazz Pharmaceuticals: Consultancy; Blueprint: Consultancy. McGrath:Constellation Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Xiao:Stemline Therapeutics: Research Funding. Nikom:Constellation Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Wang:Constellation Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Levine:Imago: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; C4 Therapeutics: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Isoplexis: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Lilly: Consultancy, Honoraria; Janssen: Consultancy; Astellas: Consultancy; Morphosys: Consultancy; Novartis: Consultancy; Amgen: Honoraria; Gilead: Honoraria; Prelude Therapeutics: Research Funding; Qiagen: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Loxo: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees. Trojer:Constellation Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company.

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Prognostic Relevance of Genetic Abnormalities in Blastic Transformation of Chronic Myeloid Leukemia

Blood ◽

10.1182/blood-2020-140629 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 3-4

Author(s):

Yotaro Ochi ◽

Kenichi Yoshida ◽

Ying-Jung Huang ◽

Ming-Chung Kuo ◽

Ko Sasaki ◽

...

Keyword(s):

Board Of Directors ◽

Clinical Outcomes ◽

Myeloid Leukemia ◽

Research Funding ◽

Pharmaceutical Research ◽

Driver Mutations ◽

Advisory Committees ◽

Tp53 Mutations ◽

Genetic Abnormalities ◽

Otsuka Pharmaceutical

Background Chronic myeloid leukemia (CML) is characterized by the BCR-ABL1 fusion gene. Despite the use of tyrosine kinase inhibitors (TKIs), a minority of chronic phase (CP) CML patients fail TKI therapies and progress to blast crisis (BC), showing dismal outcomes. Although genetic studies have revealed that CML-BC frequently carries not only ABL1 mutations but other driver mutations, our knowledge about the mechanism of TKI resistance and progression to BC is still limited by a relatively small number of patients and/or genes analyzed in each study. Moreover, it remains elusive whether mutations can predict clinical outcomes of BC patients, in which few biomarkers are known. Here, we investigated a large cohort of CML patients to reveal the landscape of genetic lesions and those predicting clinical outcomes in CML. Methods We performed whole-exome sequencing (WES) of paired CP and BC samples from 52 patients and targeted-capture sequencing that covered myeloid driver genes in 32 BC and 19 CP samples. Combined with public WES data for 24 BC and 77 CP, we analyzed a total of 108 BC and 148 CP samples. Results In WES analysis of paired CP and BC samples, an average of 5.3 nonsynonymous mutations were acquired during disease progression from CP to BC. Notably, a Poisson regression model revealed that the number of acquired mutations was positively correlated with time to progression from CP to BC (P < 0.001) and negatively with TKI therapy after CP diagnosis (P = 0.0093), although the correlation of the number of driver mutations in CML-BC with time to progression was not clear. These results suggest that the use of TKI effectively reduces the size of tumor populations at risk for clonal evolution by acquiring random mutations, by which prevents BC. In CML-BC, we found frequent mutations not only in known mutational targets in other hematological malignancies, such as RUNX1, ABL1, ASXL1, BCOR/BCORL1, TP53, and WT1, but also in other genes recently reported in BC (UBE2A and SETD1B) and previously unreported mutational targets in cancer (KLC2 and NBEAL2). Deep amplicon-sequencing revealed that ASXL1 mutations were already present at the time of CP diagnosis in most cases, whereas others such as RUNX1, ABL1, and TP53 mutations were absent in CP and newly emerged during progression to BC. Some abnormalities, such as +21, +8, and ASXL1 mutations, were more enriched in myeloid than lymphoid crisis, while others, including CDKN2A/B and IKZF1 deletions, -7/del(7p), -9/del(9p), and ABL1 mutations, vice versa. By contrast, abnormalities such as RUNX1 mutations and double Ph were almost equally observed in both crises. In univariate analysis of clinical factors for overall survival (OS) in 77 CML-BC cases for whom survival information was available, TKI-containing therapy for BC was significantly associated with a better OS, whereas genetic lesions including ASXL1 and TP53 mutations, del(17p), amp(17q), +19, and +21 had a negative impact on OS. Conspicuously, patients with TP53 mutations, del(17p), and amp(17q) showed an especially dismal outcome. We then performed a multivariate analysis using a Cox proportional hazard regression model, focusing on 36 TKI-treated patients, because TKI-containing therapy has been shown to improve OS and therefore, is a standard choice of therapy. We found that ASXL1 and BCOR mutations, complex copy-number alterations, amp(17q), and +21 were independent predictors for worse prognosis. Based on the number of these unfavorable factors, patients were classified into three subgroups showing distinct prognosis, where the 2-year OS rate was 71.8%, 15.6%, and 0% for patients with 0, 1, and ≥2 risk factors, respectively (P < 0.001). Finally, we explored the genetic abnormalities and clinical outcomes in CML-CP. In CP, only ASXL1 was mutated at a frequency comparable to that in BC, while others, including TET2, KMT2D, PTPN11, RUNX1, and WT1, were mutated at much lower frequencies. Of interest, patients who later developed BC more frequently had at least one genetic abnormality, suggesting that mutations found at the time of CP might play a role in driving CML cells to BC under the pressure of TKI treatment. Conclusion Our study clarified a comprehensive registry of genetic lesions in BC in a large cohort of CML patients and their prognostic impact, which should provide a clue to the development of better therapy/management for patients with CML. Disclosures Takaori-Kondo: Celgene: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Astellas Pharma: Honoraria, Research Funding; Ono Pharmaceutical: Research Funding; Thyas Co. Ltd.: Research Funding; Takeda: Research Funding; CHUGAI: Research Funding; Eisai: Research Funding; Nippon Shinyaku: Research Funding; Otsuka Pharmaceutical: Research Funding; Pfizer: Research Funding; OHARA Pharmaceutical: Research Funding; Sanofi: Research Funding; Novartis Pharma: Honoraria; MSD: Honoraria. Mitani:CHUGAI: Research Funding; Takeda: Research Funding; KYOWA KIRIN: Consultancy, Research Funding. Ogawa:Chordia Therapeutics, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Asahi Genomics Co., Ltd.: Current equity holder in private company; Eisai Co., Ltd.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Research Funding; KAN Research Institute, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sumitomo Dainippon Pharma Co., Ltd.: Research Funding. Shih:Novartis: Research Funding; Celgene: Research Funding; PharmaEssentia: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees.

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Preclinical Evaluation of a Novel MALT1 Inhibitor CTX-177 for Relapse/Refractory Lymphomas

Blood ◽

10.1182/blood-2020-141824 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 3-4

Author(s):

Daisuke Morishita ◽

Akio Mizutani ◽

Hirokazu Tozaki ◽

Yasuyoshi Arikawa ◽

Takuro Kameda ◽

...

Keyword(s):

Research Funding ◽

Pharmaceutical Research ◽

Antigen Receptor ◽

Receptor Signaling ◽

Malignant Lymphomas ◽

Private Company ◽

Advisory Committees ◽

Antigen Receptor Signaling ◽

Otsuka Pharmaceutical ◽

Btk Inhibitor

Among various subtypes of malignant lymphomas, activated B-cell diffuse large B-cell lymphoma (ABC-DLBCL), mantle cell lymphoma (MCL), and adult T-cell leukemia/lymphoma (ATL) are clinically intractable as patients with these lymphomas carry a dismal prognosis, with long-term survival rates of 10-30%. Therefore, a novel therapeutic strategy is required to better manage patients with these malignancies. Recently, we and other investigators performed comprehensive genetic studies and revealed frequent genetic alterations in B and T cell antigen receptor signaling and NF-κB pathway, such as CD79A/B and CARD11 mutations in ABC-DLBCL and PLCG1, PRKCB, and CARD11 mutations in ATL, suggesting the biological relevance of this pathway. To exploit a new treatment strategy in these malignant lymphomas, we focused on the protease mucosa-associated lymphoid tissue lymphoma translocation 1 (MALT1) which is a key regulator of the antigen receptor signaling and NF-κB pathway and forms a complex with CARD11 and BCL10, and developed a novel compound CTX-177 to inhibit MALT1 with high potency and specificity. CTX-177 was efficacious against ABC-DLBCL and MCL models in vitro and in vivo. Moreover, CTX-177 exhibited combination synergistic effect with BTK inhibitor. In addition, the MALT1 inhibitor showed an anti-tumor effect against CARD11 mutated ABC-DLBCL model, which is resistant to BTK inhibitor. To further explore efficacy of CTX-177 against malignant lymphomas, we generated animal models such as genetically engineered mice and patient-derived xenograft models recapitulating molecular features of these diseases, and examined the response to the MALT1 inhibitor. In these experiments, target engagement of CTX-177 was confirmed by detecting digested substrates of MALT1, and mode of action was evaluated by downregulation of oncogenic transcriptional factor IRF4 which is critical for lymphoma survival. Importantly, the relationship of susceptibility to MALT1 inhibition and gene mutations was analyzed to identity a patient selection biomarker for CTX-177. In summary, the novel, selective, small-molecule MALT1 inhibitor CTX-177 demonstrated preclinical efficacy along with target engagement in several lymphoma models with activated antigen receptor signaling and NF-κB pathway. Our results underscore the preclinical therapeutic potential of CTX-177 as a single-agent or in combination with other inhibitors like BTK inhibitor for the treatment of malignant lymphomas. Disclosures Morishita: Chordia Therapeutics Inc.: Current Employment, Current equity holder in private company. Mizutani:Chordia Therapeutics Inc.: Current Employment, Current equity holder in private company. Tozaki:Chordia Therapeutics Inc.: Current Employment, Current equity holder in private company. Arikawa:Chordia Therapeutics Inc.: Current Employment, Current equity holder in private company. Kataoka:CHUGAI PHARMACEUTICAL CO., LTD.: Research Funding; Takeda Pharmaceutical Company: Research Funding; Otsuka Pharmaceutical: Research Funding; Asahi Genomics: Current equity holder in private company. Yoda:Chordia Therapeutics Inc.: Research Funding. Izutsu:Symbio: Research Funding; Solasia: Research Funding; Celgene: Research Funding; Chugai: Research Funding; Novartis: Research Funding; Ono Pharmaceutical: Research Funding; Bayer pharmaceuticals: Research Funding; Daiichi Sankyo: Research Funding; AstraZeneca: Research Funding; Eisai: Research Funding; Incyte: Research Funding; Abbvie pharmaceuticals: Research Funding; HUYA Japan: Research Funding; Sanofi: Research Funding; Janssen: Research Funding; Yakult: Research Funding. Minami:Bristol-Myers Squibb Company: Honoraria; Novartis Pharma KK: Honoraria; Pfizer Japan Inc.: Honoraria; Takeda: Honoraria. Shimoda:Otsuka Pharmaceutical: Research Funding; Pfizer Inc.: Research Funding; Kyowa Hakko Kirin Co., Ltd.: Research Funding; CHUGAI PHARMACEUTICAL CO., LTD.: Research Funding; Merck & Co.: Research Funding; Astellas Pharma: Research Funding; AbbVie Inc.: Research Funding; PharmaEssentia Japan: Research Funding; Perseus Proteomics: Research Funding; Celgene: Honoraria; Shire plc: Honoraria; Bristol-Myers Squibb: Honoraria; Takeda Pharmaceutical Company: Honoraria; Novartis: Honoraria, Research Funding; Asahi Kasei Medical: Research Funding; Japanese Society of Hematology: Research Funding; The Shinnihon Foundation of Advanced Medical Treatment Research: Research Funding. Miyake:Chordia Therapeutics Inc.: Current Employment, Current equity holder in private company. Ogawa:KAN Research Institute, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Chordia Therapeutics, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Asahi Genomics Co., Ltd.: Current equity holder in private company; Otsuka Pharmaceutical Co., Ltd.: Research Funding; Sumitomo Dainippon Pharma Co., Ltd.: Research Funding; Eisai Co., Ltd.: Research Funding.

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Post-Treatment Clone Size Predicts Survival Independently of IPSS-R and Response after Azacitidine Therapy for MDS.

Blood ◽

10.1182/blood-2020-139082 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 12-13

Author(s):

Yasuhito Nannya ◽

Magnus Tobiasson ◽

Shinya Sato ◽

Elsa Bernard ◽

Maria Creignou ◽

...

Keyword(s):

Clinical Response ◽

Board Of Directors ◽

Research Funding ◽

Post Treatment ◽

Private Company ◽

Advisory Committees ◽

Clone Size ◽

Otsuka Pharmaceutical ◽

Pre Treatment

Background DNA hypomethylating agents (HMAs), including azacytidine (AZA) have been established as key drugs for higher-risk myelodysplastic syndromes (MDS). We and others have explored the role of mutation profile before AZA administration on predicting outcomes. Actually, we have previously identified mutated-TP53 as a marker associated with higher rate of achieving complete remission (CR). In addition, mutations in TP53 and DDX41 predicted reduced and prolonged survival after treatment, respectively. However, the clinical significance of evaluating clone size changes early after treatment has not been determined. In this study, we explored the role of post-treatment clone size in predicting outcomes of AZA treatment for MDS and related diseases. Methods We enrolled 290 AZA-treated cases, including 88 from a Japanese prospective study (JALSG MDS-212 trial), 149 from Karolinska Institute, and 53 from a retrospectively collected Japanese cases. The diagnoses were MDS (n=242), MDS/MPN (n=25), and AML-MRC (n=23). For all patients, tumor samples were collected both before and after AZA administration and were analyzed for mutations in 66 genes implicated in myeloid neoplasms using targeted-capture sequencing. The median cycles of AZA treatment before sampling was 4 (range 1-7). Clone size was calculated from variant allele frequency adjusted for ploidy or allelic imbalances.Survival was calculated with a Cox regression model. Results In post-treatment samples, we identified 870 mutations in 51 genes in 255 (88%) patients with a median of 3 mutations per sample, while 943 mutations were seen in 279 (96%) patients in the pre-treatment samples. Most frequently detected mutations in post-treatment samples were seen in TET2, TP53, RUNX1, and ASXL1. Germline DDX41 mutations were excluded from clone size evaluation. Median clone sizes were 0.63 and 0.54 for pre-treatment and post-treatment samples (P=.011), respectively. The largest clone sizes (max(VAF)) in post-treatment samples had a strong negative correlation with hematological response according to IWG criteria (P < .0001). We next explored whether max(VAF) in post-treatment samples provides a more precise estimation of long-term survival than IPSS-R. Max(VAF) further stratified each IPSS-R risk group in subgroups with discrete OS (P < .0001 for IPSS-R very high and P = .0004 for high risk group). Incorporating pre-treatment mutation data (mutations in TP53 and DDX41) and max(VAF) values in addition to IPSS-R scores and clinical response, we constructed a multivariate model and found that all these factors had an independent and significant impact on OS (Figure 1A). Next, we examined whether max(VAF) combined with IPSS-R and clinical response can improve the model. For this purpose, we randomly split the cohort into 75% training and 25% validation subsets and for each split, we constructed different models using the training set, performance of which was evaluated by calculating the concordance index (c-index) using the validation set. The mean c-index in 10,000 simulation sets increased by 0.025 by adding response data to IPSS-R score (I versus IR in Fig 1B). Further improvements were obtained by adding gene mutation and max(VAF), in which the c-index increased by 0.034 (IR versus IGR in Fig 1B) and 0.010 (IGR versus IGRP in Fig 1B), respectively. For the 53 patients who received allogeneic stem cell transplantation, the median post-transplant OS was 82.6 months (range, 36.3 to not reached). Notably, max(VAF) significantly stratified OS after allo-SCT (HR, 3.3; 95%CI, 1.3 to 8.3; P = .014). Conclusions Our study revealed that post-treatment clone size significantly correlated with clinical response and the evaluation of post-treatment clone size allows for more precise prognostication after AZA treatment compared with IPSS-R and clinical response alone. Table Disclosures Naoe: NIPPON SHINYAKU CO.,LTD.: Speakers Bureau; Sysmex co.: Speakers Bureau; Eisai Co., Ltd.: Speakers Bureau; Astellas Pharma Inc.: Speakers Bureau; Bristol-Myers Squibb Company: Speakers Bureau. Miyazaki:Celgene: Honoraria; Sumitomo Dainippon Pharma Co., Ltd.: Honoraria; Kyowa Kirin Co., Ltd.: Honoraria; Novartis Pharma KK: Honoraria; NIPPON SHINYAKU CO.,LTD.: Honoraria; Otsuka Pharmaceutical: Honoraria; Astellas Pharma Inc.: Honoraria; Chugai Pharmaceutical Co., Ltd.: Honoraria. Papaemmanuil:Kyowa Hakko Kirin: Consultancy, Honoraria; Prime Oncology: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Illumina: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; MSKCC: Patents & Royalties; Isabl: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees. Ogawa:Eisai Co., Ltd.: Research Funding; Chordia Therapeutics, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; KAN Research Institute, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Otsuka Pharmaceutical Co., Ltd.: Research Funding; Asahi Genomics Co., Ltd.: Current equity holder in private company; Sumitomo Dainippon Pharma Co., Ltd.: Research Funding.

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Mutations in CRBN and Other Cereblon Pathway Genes Are Only Associated with Acquired Resistance to Immunomodulatory Drugs in a Subset of Patients and Cell Line Models

Blood ◽

10.1182/blood-2020-140024 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 6-7

Author(s):

Amy Barber ◽

John R Jones ◽

Harvey Che ◽

Yann-Vai Le Bihan ◽

Niels Weinhold ◽

...

Keyword(s):

Cell Line ◽

Board Of Directors ◽

Research Funding ◽

Cross Resistance ◽

Immunomodulatory Drugs ◽

Private Company ◽

Advisory Committees ◽

Data Set ◽

Synonymous Mutations

Background: Immunomodulatory drugs (IMiDs) are the current backbone of standard and experimental combination myeloma therapies at all stages of disease, but the majority of patients eventually relapse. The mechanisms driving IMiD resistance are poorly understood. Previous studies looking for genetic drivers of resistance have looked at core members of the CRL4CRBN E3-ubiquitin ligase complex (CUL4-RBX1-DDB1-CRBN) and identified infrequent mutations and deletions in cereblon (CRBN), but at a rate that cannot account for resistance in the majority of patients. More recently several in vitro studies have identified novel regulators of cereblon activity including the COP9 signalosome, E2 ubiquitin conjugating enzymes, neddylation modifiers and additional IMiD neosubstrates. In this study paired presentation/relapse samples from newly diagnosed patients recruited to a clinical trial (UK NCRI Myeloma XI trial: NCT01554852) of largely IMiD-based therapies were used to investigate the role of mutations and deletions in all genes implicated in IMiD activity. For comparison, cell line models of resistance were generated in vitro. Methods: 56 patients who received IMiD induction therapy followed by either lenalidomide maintenance (n=30) or observation (n=26), and subsequently relapsed, underwent whole exome sequencing (WES) of CD138+ cells, median depth 122x for tumour samples and 58x for paired germline controls. Non-synonymous mutations and deletions present in tumour but not germline controls were considered. Cell line models were generated using the IMiD sensitive MM1s cell line. Cells were cultured in 10xGI50 concentrations of lenalidomide/pomalidomide alongside a control exposed to the same %DMSO. WES was carried out and non-synonymous mutations identified. Mutations present in the lenalidomide resistant (Len-R) and pomalidomide resistant (Pom-R) but not their relevant DMSO exposed control were considered. From recent publications a list of 42 genes (Figure 1) involved in cereblon pathway regulation and IMiD response was curated, termed "CRBN/IMiD genes". Mutations in CRBN/IMiD genes in the patient dataset and cell line models were examined. Results: In the patient data set 12/42 (28.6%) of the CRBN/IMiD genes were found to be mutated, with a total of 17 mutations in 14/56 (25%) patients identified. 9/17 (53%) were identified in patients who had received lenalidomide maintenance and 8/17 (47%) in the observation group. Importantly, in the patients receiving lenalidomide maintenance, 6 of the 9 (66.7%) mutations had a higher cancer clonal fraction (CCF) at relapse, suggesting they may have been selected for by exposure to treatment. Comparatively, in mutations identified in patients undergoing observation, only 3 of the 8 (37.5%) mutations had a higher CCF at relapse compared with presentation. The only deletion in CRBN/IMiD genes was in SETX, in one patient at relapse. Only one mutation or deletion was identified in CRBN itself, a missense mutation at relapse at g.3:3195148A>C, encoding a Cys326Gly sequence modification at the protein level. Interestingly, Cys326 is one of 4 cysteines in CRBN coordinating a single zinc ion to form a Zn finger motif, which stabilises the Thalidomide Binding Domain (TBD) of the protein, suggesting this mutation may have had functional significance. In the cell line models full resistance up to 100xGI50 concentrations was established by 12 weeks. The resistant cell lines had cross-resistance to the other IMiDs and comparable morphology, growth rates and responses to non-IMiD drugs as their sensitive counterpart. Resistant cells had reduced levels of CRBN mRNA and protein expression. Functional assays demonstrated that well characterised downstream effects of IMiD treatment were abrogated: transcription factors Ikaros and Aiolos not degraded and no downregulation of IRF4 mRNA. The Pom-R cell line had a mutation affecting a CRBN splice site 5' of exon 8. No other mutations or deletions in the 42 IMiD pathway genes were identified in either the Len-R or Pom-R lines. Conclusions: CRBN and other genes in the IMiD response pathway were mutated or deleted in around 25% of patients suggesting other mechanisms, for example epigenetic alterations, underlie resistance acquisition in a significant proportion. Models for both CRBN/IMiD gene mutated and unmutated resistant states have been generated and will be used to study mechanisms of IMiD resistance. Figure Disclosures Jones: Celgene: Honoraria, Research Funding. Che:Monte Rosa Therapeutics: Research Funding. Le Bihan:Monte Rosa Therapeutics: Research Funding. Wang:Monte Rosa Therapeutics: Research Funding. Kaiser:Bristol-Myers Squibb, Chugai, Janssen, Amgen, Takeda, Celgene, AbbVie, Karyopharm, GlaxoSmithKline: Consultancy; Janssen, Amgen, Celgene, Bristol-Myers Squibb, Takeda: Honoraria; Bristol-Myers Squibb/Celgene, Janssen, Karyopharm: Research Funding; Bristol-Myers Squibb, Takeda: Other: Travel expenses. Jackson:Takeda: Honoraria, Research Funding, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau; Gsk: Honoraria, Speakers Bureau; Celgene: Honoraria, Research Funding, Speakers Bureau. Davies:Celgene/BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotech: Honoraria; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees. Chopra:Apple Tree Life Sciences: Current Employment; Monte Rosa Therapeutics: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Research Funding. Morgan:GSK: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Janssen: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Pawlyn:Takeda: Consultancy, Other: Travel expenses; Celgene: Consultancy, Honoraria, Other: Travel expenses; Janssen: Honoraria, Other: Travel expenses; Amgen: Consultancy, Other: Travel expenses.

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Older Age and Increased Neutrophil-to-Lymphocyte Ratio (NLR) Are Predictors of Mortality in a Multiethnic Urban Cohort of Hematologic Neoplasms and COVID-19 Patients

Blood ◽

10.1182/blood-2020-138842 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 34-35

Author(s):

Angelica D'Aiello ◽

Sumaira Zareef ◽

Kith Pradhan ◽

Amanda Lombardo ◽

Fariha Khatun ◽

...

Keyword(s):

Cancer Treatment ◽

Board Of Directors ◽

Median Time ◽

Lymphocyte Count ◽

Research Funding ◽

Hematologic Neoplasms ◽

Private Company ◽

Advisory Committees ◽

Treatment Status ◽

Race Ethnicity

Introduction: We sought to compare outcomes among patients with hematologic neoplasms diagnosed with COVID-19 infection in a multiethnic urban academic medical center. Methods: A retrospective analysis of patients with hematologic neoplasms diagnosed with COVID-19 from March 17th to June 8th2020 was conducted. Subjects included were censored at last point of contact. Variables collected included age, gender, race/ethnicity, hematologic diagnosis, cancer treatment status, baseline and follow-up COVID-19 testing, neutrophil count, and lymphocyte count at time of diagnosis. Associations between hematologic diagnosis, cancer treatment status, age, gender, race/ethnicity, neutrophil-to-lymphocyte ratio (NLR), and overall survival (OS) were assessed using the Kaplan-Meier method with logrank test. Results: A total of 102 subjects with hematologic neoplasms and COVID-19 infection treated in Montefiore Health system were identified (Table 1). Thirty-nine (38%) subjects were undergoing active treatment, including 17 (16%) receiving conventional chemotherapy agents, 12 (12%) targeted therapy, and 10 (10%) combination therapy. Of those subjects, twenty (50%) experienced delay or discontinuation of treatment due to COVID-19 infection. Four subjects (4%) showed persistent infection by PCR at median duration of 25.1 days after initial diagnosis. Ten subjects (9.8%) showed clearance of the virus by PCR with median time-to-clearance of 51.8 days. Of 9 subjects with serologic testing, 8 tested positive for COVID-19 IgG antibody at median time of 62 days after initial COVID-19 diagnosis. Forty-seven (47%) subjects expired as a result of COVID-19 disease at the time of analysis. Disease type, treatment status, race/ethnicity, age, and gender showed no significant association with mortality. Patients older than 70 had worse outcomes than the younger population (p = 0.0082). Median neutrophil and lymphocyte count at time of diagnosis was 4500 and 900, respectively. NLR greater than 9 was associated with worse survival when compared to NLR less than 9 (p=0.0067). Conclusions: COVID-19 infection has adverse effects on patients with hematological neoplasms. Subjects older than 70 years had a significantly worse prognosis. Notably, subjects actively being treated with chemotherapy did not have worse outcomes than those not being treated in our cohort, supporting the notion than active COVID-19 infection per se should not result in treatment delays. In addition, high NLR correlates with worsened survival, suggesting that this could be a potential prognostic factor for COVID-19 mortality in the hematologic neoplasms population. Disclosures Steidl: Stelexis Therapeutics: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Bayer Healthcare: Research Funding; Pieris Pharmaceuticals: Consultancy; Aileron Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Verma:stelexis: Current equity holder in private company; BMS: Consultancy, Research Funding; Medpacto: Research Funding; Janssen: Research Funding; acceleron: Consultancy, Honoraria.

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The Interaction of Bortezomib with P-Gp, MRP-1 and BCRP Drug Transporters: Implications for Therapeutic Applications of Bortezomib in Advanced Multiple Myeloma and Other Neoplasias.

Blood ◽

10.1182/blood.v114.22.1729.1729 ◽

2009 ◽

Vol 114 (22) ◽

pp. 1729-1729

Author(s):

Melissa G Ooi ◽

Robert O'Connor ◽

Jana Jakubikova ◽

Justine Meiller ◽

Steffen Klippel ◽

...

Keyword(s):

Lung Cancer ◽

Multiple Myeloma ◽

Cell Line ◽

Board Of Directors ◽

Cell Lines ◽

Research Funding ◽

Significant Activity ◽

Cancer Resistance ◽

Advisory Committees ◽

Bortezomib Treatment

Abstract Abstract 1729 Poster Board I-755 Background Multidrug transporters are energy-dependent transmembrane proteins which can efflux a broad range of anticancer drugs and thereby play a role in resistance to the actions of substrate agents. Classically, three transporters, p-glycoprotein (Pgp; MDR-1; ABCB1), multidrug resistant protein-1 (MRP-1; ABCC1) and breast cancer resistance protein (BCRP; MXR; ABCG2), have been found to have the broadest substrate specificity and a strong correlation with drug resistance in vitro and in vivo in many models and forms of cancer. We have sought to characterize the interaction of bortezomib with these transporters and thereby explore the potential for these agents to play a role in resistance. Bortezomib is a novel proteosome inhibitor with significant activity in multiple myeloma, although subsets of patients remain refractory to the activity of the drug. Hence, better characterization of the interactions of this drug with classical resistance mechanisms may identify improved treatment applications. Methods and Results We investigated the role of these transporters by using isogenic cell line models which are resistant due to overexpression of a particular transporter: DLKP lung cancer cell line that overexpresses MRP-1; DLKP-A which overexpresses Pgp; and DLKP-SQ-Mitox which overexpresses BCRP. DLKP-A cells exhibited a 4.6-fold decrease in responsiveness to bortezomib compared to parental DLKP cells. In DLKP-SQ-Mitox, bortezomib-induced cytotoxicity was comparable to DLKP. When bortezomib was combined with elacridar, a Pgp and BCRP inhibitor, significant synergy was evident in DLKP-A (100% viable cells with single agent treatment versus 11% with the combination), but not DLKP-SQ-Mitox. Sulindac, an MRP-1 inhibitor, combined with bortezomib failed to produce any synergy in MRP-1 positive DLKP cells. Conversely, combination assays of Pgp substrate cytotoxics such as doxorubicin with Bortezomib were largely additive in nature. This indicates that bortezomib has little, if any, direct Pgp inhibitory activity, as combinations of a traditional Pgp inhibitor (such as elacridar) and doxorubicin would show marked synergy rather than just an additive effect in Pgp positive cells. To further characterize the extent of this interaction with Pgp, we conducted cytotoxicity assays in cell lines with varying levels of Pgp overexpression. NCI/Adr-res (ovarian cancer, high Pgp overexpression), RPMI-Dox40 (multiple myeloma, moderate Pgp overexpression) and A549-taxol (lung cancer, low Pgp overexpression). The combination of bortezomib and elacridar that produced the most synergy was in cell lines expressing moderate to high levels of Pgp expression. Cell lines with lower Pgp expression produced an additive cytotoxicity. We next examined whether bortezomib had any direct effect on Pgp expression. In RPMI-Dox40 cells, Pgp expression is reduced in a time-dependent manner with bortezomib treatment. Conclusions Our studies therefore show that bortezomib is a substrate for Pgp but not the other drug efflux pumps. In tumor cells expressing high levels of Pgp, the efficacy of bortezomib is synergistically enhanced by combinations with a Pgp inhibitor, while bortezomib treatment itself can reduce the expression of Pgp. This study suggests that in the subset of patients with advanced multiple myeloma or solid tumors which express high levels of Pgp, inhibition of its function could contribute to enhanced responsiveness to bortezomib. Disclosures Richardson: millenium: Membership on an entity's Board of Directors or advisory committees, Research Funding; celgene: Membership on an entity's Board of Directors or advisory committees, speakers bureau up to 7/1/09; MLNM: speakers bureau up to 7/1/09. Mitsiades:Millennium Pharmaceuticals : Consultancy, Honoraria; Novartis Pharmaceuticals : Consultancy, Honoraria; Bristol-Myers Squibb : Consultancy, Honoraria; Merck &Co: Consultancy, Honoraria; Kosan Pharmaceuticals : Consultancy, Honoraria; Pharmion: Consultancy, Honoraria; PharmaMar: licensing royalties ; Amgen Pharmaceuticals: Research Funding; AVEO Pharma: Research Funding; EMD Serono : Research Funding; Sunesis Pharmaceuticals: Research Funding. Anderson:Celgene: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Biotest AG: Consultancy, Research Funding.

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CYC065, a Potent Derivative of Seliciclib Is Active In Multiple Myeloma In Preclinical Studies

Blood ◽

10.1182/blood.v116.21.2999.2999 ◽

2010 ◽

Vol 116 (21) ◽

pp. 2999-2999 ◽

Cited By ~ 1

Author(s):

Samantha Pozzi ◽

Diana Cirstea ◽

Loredana Santo ◽

Doris M Nabikejje ◽

Kishan Patel ◽

...

Keyword(s):

Cell Cycle ◽

Multiple Myeloma ◽

Cell Line ◽

Board Of Directors ◽

Cell Lines ◽

Preliminary Data ◽

Research Funding ◽

Preclinical Studies ◽

Dependent Manner ◽

Advisory Committees

Abstract Abstract 2999 Multiple myeloma (MM) is a treatable but incurable hematological malignancy and novel targeted therapies are under investigation. MM is characterized by dysregulation of the cell cycle, consequent to the overexpression of cyclins and their related kinases, the cyclins dependent kinases (CDK), a group of Ser/Thr proteine kinases. CDKs represent a promising therapeutic target, and inhibitors have been developed for anticancer treatment. We have previously studied seliciclib in the context of MM. CYC065, a second generation CDK inhibitor is the more potent derivative of seliciclib. It is mainly active on CDK 2, 5 and 9, involved in progression of the cell cycle and protein transcription. It has already shown promising results in preclinical studies in breast cancer and acute leukemia. We tested CYC065 in in vitro experiments in MM. Our preliminary data in 7 MM cell lines showed cytotoxicity of CYC065, both in MM cell lines sensitive as well as resistant to conventional chemotherapy, with an IC50 ranging between 0.06 and 2μ M, at 24 and 48h. Tritiated thymidine uptake assay confirmed the antiproliferative effects of CYC065 in MM, and its ability to overcome the growth advantage conferred by co-culture with bone marrow stromal cells derived from MM patients, and cytokines like interleukin 6 (10ng/ml) and insulin like growth factor-1 (50ng/ml). The anti-proliferative effect was evident both at 24 and 48h, starting at concentrations as low as 0.015μ M. The AnnexinV/PI assay in the MM1.s cell line confirmed CYC065's ability to induce apoptosis in a time dependent manner starting at 9 hours of treatment, at a concentration of 0.125 μ M, inducing 82% of apoptosis after 48h of exposure. Cell cycle analysis in the same MM1.s cell line showed an increase of subG1 phase, starting at 9 hours of treatment, at 0.125 μ M of CYC065. Preliminary results of western blot analysis confirmed the apoptotic effect of CYC065 in the MM1s cell line, highlighted by the cleavage of caspase 3, 8, 9 and PARP. The compound was tested in primary CD138+ cells isolated from three refractory MM patients, confirming its efficacy at 0.125 μ M, both at 24 and 48h. Comparative analysis in PBMCs from normal donors, for the evaluation of the drug toxicity is ongoing and will be presented. In conclusion our preliminary data confirm the efficacy of CYC065 in MM cell lines and primary MM cells, at nanomolar concentrations. Ongoing mechanistic and in vivo studies will delineate its role in the now increasing spectrum of CDK inhibitors in MM and better define its potential for clinical development in MM. Disclosures: Green: Cyclacel: Employment. Anderson:Millennium Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Scadden:Fate Therapeutics: Consultancy, Equity Ownership, Patents & Royalties. Raje:Celgene: Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Research Funding; Acetylon: Research Funding.

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An Update On The Clinical Activity Of Resimmune, a Targeted Therapy Directed To CD3 Receptor, In Patients With Cutaneous T Cell Lymphomas--CTCL

Blood ◽

10.1182/blood.v122.21.4381.4381 ◽

2013 ◽

Vol 122 (21) ◽

pp. 4381-4381 ◽

Cited By ~ 2

Author(s):

Arthur E. Frankel ◽

Jung H Woo ◽

Jeremy P Mauldin ◽

Francine M. Foss ◽

Madeleine Duvic ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Pichia Pastoris ◽

Cell Line ◽

Board Of Directors ◽

Research Funding ◽

Response Rate ◽

The United States ◽

Advisory Committees ◽

Systemic Therapies

Abstract Cutaneous T cell lymphoma—CTCL is a malignancy of skin-tropic T cells. CTCL cells have ubiquitous overexpression of CD3. Although uncommon, CTCL has been estimated to affect 1,500 patients per year in the United States. There are multiple approved systemic therapies for CTCL, but responses are brief lasting months. Allogeneic stem cell transplantation may provide long-term remissions, but is suitable for only rare CTCL patients. Overall, CTCL has a long clinical course with relentless progression over months to years with estimated median survival of 3-5 years for stage IB-IIB patients. The CD3 targeted agent, Resimmune, was synthesized and prepared for clinical use. It consists of the catalytic and translocation domains of diphtheria toxin fused to two anti-human CD3 Fv fragments. DNA encoding Resimmune protein was integrated into the Pichia pastoris genome, and recombinant protein was produced in Pichia pastoris via the secretory route (Woo, Protein Expr Purif 25, 270, 2002). Protein was purified by anion exchange and size exclusion chromatography. The CD3+ Jurkat cell line incubated with Resimmune yielded an IC50 for protein synthesis inhibition of 0.017pM. The CD3- Vero cell line incubated with Resimmune showed an IC50 >10pM. Mice, rats, and monkeys given total doses of >200mg/kg over four days showed only transient transaminasemia without histopathologic tissue injury or clinical signs or symptoms (Woo, Cancer Immunol Immunother 57, 1225, 2008). In a mouse model with human CD3e transfected lymphocytes, four logs of antigen positive cells were reproducibly depleted from nodes and spleen with 100mg/kg total dose of Resimmune (Thompson, Protein Eng 14, 1035, 2001). Based on these findings, a phase 1 study was initiated and this report serves to update the results of a single cycle of Resimmune given at 2.5-11.25mg/kg 15 min IV infusion twice daily for 8 doses to 18 CTCL patients. There were 10 females and 8 males with ages 20-81 years. Two patients were naïve to systemic therapies, and all others had failed 1-4 prior treatments including interferon, bexarotene, gemcitabine, vorinostat, chlorambucil, etoposide, pralatrexate, doxil, romidepsin, methotrexate, CHOP, and brentuximab vedotin. None of the Resimmune treated CTCL patients had dose-limiting toxicities. Side effects were mild-moderate and transient with fevers, chills, nausea, transaminasemia, hypoalbuminemia, lymphopenia, reactivation of EBV and CMV, and hypophosphatemia. Toxicities responded to antipyretics, anti-emetics, albumin infusions, rituximab treatment and valgancyclovir. Among measured patients, there was a 3 log decline in normal, circulating T cells by day 5 that recovered by day 14. Because of vascular leak syndrome toxicities in non-CTCL patients, the MTD was defined as 7.5mg/kg x 8 doses. Cmax ranged from 1.9-40.7ng/mL and half-life from 5-66min. Pretreatment anti-DT titers were 0.9-251mg/mL and day 30 post-therapy increased to 5-4059 mg/mL. 17 CTCL patients were evaluable for response. There were six responses for a response rate of 35%. There were four CRs (24% CR rate). Three of the CRs are over 4-years duration. Patients with IB or IIB disease and mSWAT<50 had an overall response rate of 86% and CR rate of 56%. The long time required to convert from a PR to a CR in the absence of any additional therapy beyond the four treatment days suggest an additional anti-tumor mechanism beyond immunotoxin-induced killing such as immunomodulation. Accrual of patients with mSWAT scores of 50 or less is ongoing. Disclosures: Woo: Angimmune: Patents & Royalties, Research Funding. Foss:celgene: Honoraria, Research Funding; millenium: Honoraria, Membership on an entity’s Board of Directors or advisory committees; eisai: Membership on an entity’s Board of Directors or advisory committees; spectrum: Research Funding; merck: Research Funding; seattle genetics: Research Funding. Neville:Angimmune: Employment, Equity Ownership, Patents & Royalties.

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Tolinapant (ASTX660), a Non-Peptidomimetic Antagonist of cIAP1/2 and XIAP, and the HDAC Inhibitor Romidepsin Are Synergistic in in Vitro Models of T Cell Lymphoma

Blood ◽

10.1182/blood-2021-153451 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 4356-4356

Author(s):

John S Manavalan ◽

Ipsita Pal ◽

Aidan Pursley ◽

George A. Ward ◽

Tomoko Smyth ◽

...

Keyword(s):

T Cell ◽

Cell Line ◽

Board Of Directors ◽

Cell Lines ◽

Research Funding ◽

Cell Lymphoma ◽

T Cell Lymphoma ◽

Tnf Alpha ◽

Sensitive Cell ◽

Advisory Committees

Abstract Background: The PTCL are a heterogeneous group of non-Hodgkin lymphomas originating from mature T-lymphocytes. They are aggressive diseases, often resistant to conventional chemotherapy. Despite the fact that a number of new agents have been approved, treatment paradigms tailored to the biology of the disease have yet to emerge. Tolinapant (ASTX660) is a potent antagonist of both cellular and X-linked inhibitors of apoptosis proteins (cIAP1/2 and XIAP), and is presently in phase I/II trials in patients with advanced solid tumors and lymphomas (NCT02503423). IAP antagonists enhance tumor necrosis factor (TNF) receptor superfamily mediated apoptosis (Ward GA, et al. Mol Cancer Ther. 2018), are potent anti-tumor immune enhancers and induce markers of immunogenic cell death such as damage associated molecular patterns (DAMPs; Ye W, et al, Oncoimmunology, 2020). Objectives: We explored the sensitivity of a range of T-cell lymphoma (TCL) cell lines to tolinapant. We establish the synergy coefficient between tolinapant and the HDAC inhibitor, romidepsin, and interrogated the molecular basis of their synergistic interaction. Methods: A panel of human T-cell lymphoma cell lines were tested in proliferation assays (CellTiterGlo) for sensitivity to tolinapant in the presence or absence of 10ng/ml of TNF alpha. For combination studies, with tolinapant and romidepsin, each drug was tested at the IC10 and IC40 concentrations in the presence or absence of TNF alpha. Synergy scores using the Excess over Bliss (EOB) model were calculated using SynergyFinder (Aleksandr Ianevski et al; Nucleic Acids Research, 2020). Additionally, the effects of tolinapant and romidepsin on the IAPs and caspases were analyzed by western blots. TNFR1 receptor expression and induction of DAMPs were also analyzed by flow cytometry. Results: TCL Lines demonstrated varying sensitivities to tolinapant in the presence or absence of TNF alpha. The most sensitive cell lines, ALK+ ALCL and SUP-M2, had IC50 concentrations ranging from 200nM ± 100nM to 20nM ± 1nM in the absence or presence of TNF alpha, respectively, at 24, 48 and 72hrs, while a resistant CTCL cell line HH had an IC50 concentration of over 20mM, even in the presence of TNF alpha. Interestingly, using western blot analysis, we found that the presence of TNF alpha increased the levels of cIAP1 in the tolinapant sensitive SUP-M2 cell line, but not in the resistant HH cell line. However, there was a concentration dependent decrease in cIAP1 but not in XIAP in both cell lines treated with tolinapant. Flow cytometry analysis demonstrated that tolinapant increases the expression of TNFR1 and DAMPs in a dose dependent manner on the sensitive SUP-M2, but not in the resistant HH cells. In combination experiments, using the EOB model, tolinapant plus romidepsin was found to be synergistic in the absence of TNF alpha, at 36hrs, in both the sensitive cell line SUP-M2 and the resistant cell line HH. In the presence of TNF alpha, synergism was seen only in the sensitive cell line SUP-M2 and antagonistic in the HH cell line (Fig. 3). In the tolinapant plus romidepsin treated samples, cIAP1 levels decreased in the SUP-M2 cell line, in the absence of TNF alpha, however, addition of TNF alpha did not alter the levels of cIAP1 in the SUP-M2 cells. The cIAP1 levels decreased in the HH cells treated with the combination, in both the presence or absence of TNF alpha (Figure). Our findings indicate that the synergy of the tolinapant plus romidepsin is not dependent on the presence of TNF alpha. Conclusion: Tolinapant has demonstrated potent cytotoxic effects against a broad range of TCL lines both as a monotherapy and in combination with the HDAC Inhibitor, romidepsin. In in vitro studies, T cell lymphoma cell lines demonstrated varying sensitivity to tolinapant with certain cell lines being more resistant, even in the presence of TNF alpha. Interestingly, the addition of romidepsin appeared to overcome the intrinsic resistance to tolinapant in the absence of TNF alpha. These data provide the rationale to continue to explore the combination of tolinapant and romidepsin in vivo and to investigate additional combinations with T-cell specific agents (e.g. pralatrexate, belinostat, azacitidine and decitabine). Figure 1 Figure 1. Disclosures Smyth: Astex Pharmaceuticals: Current Employment. Sims: Astex Pharmaceuticals: Current Employment. Loughran: Kymera Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bioniz Therapeutics: Membership on an entity's Board of Directors or advisory committees; Keystone Nano: Membership on an entity's Board of Directors or advisory committees; Dren Bio: Membership on an entity's Board of Directors or advisory committees. Marchi: Kyowa Kirin: Honoraria; Myeloid Therapeutics: Honoraria; Astex: Research Funding; BMS: Research Funding; Merck: Research Funding; Kymera Therapeutics: Other: Scientific Advisor.

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