Drug Combo Research Articles

Drug Combo Better than Single Agent in EGFR, MET-Mutated NSCLC

Drug Combo Better than Single Agent in EGFR, MET-Mutated NSCLC

CDKL5 gene; cerebrospinal fluid; drug combo for fragile X syndrome

CDKL5 gene; cerebrospinal fluid; drug combo for fragile X syndrome

Utilizing Drug Combo to improve the design of phase 1 trials for anticancer drugs.

1571 Background: Accurate prior knowledge of a single drug or drug combination on toxicity, pharmacokinetics (PK), maximum tolerated dose (MTD), and dose-limiting toxicity (DLT) can help oncologists and statisticians design an efficient phase 1 clinical trial. However, most of the relevant knowledge is shattered in various databases. More importantly, MTD and DLT are missing in any databases. This study constructed a comprehensive knowledge base with expert-curated MTD and DLT knowledge from published anticancer drug combination phase 1 clinical trial results. We also demonstrated the utility of the knowledgebase to design a more efficient phase 1 trial. Methods: Toxicity, pharmacology, and PK knowledge were integrated from publicly available data sources, including DrugBank, SIDER, and drug labels. An interdisciplinary team manually curated the MTD and DLT knowledge. Relevant papers were discovered by PubMed keyword search (drug name + MTD or RP2D). Details regarding patient eligibility, treatment information (dose, formula, and schedule), trial design method, dose levels, DLT definition, MTD or Recommended phase 2 dose, and DLT incident were curated in the structured data format and stored in a database. Rxnorm and MedDRA were used for normalizing drug names and DLT. Results: Currently, 2358 papers on cancer drugs phase 1 trial have been curated. Additionally, pharmacological and PK knowledge of 197 cancer drugs, ADE information from 1094 drug labels, and more than 500000 pieces of DDI evidence were integrated into the knowledge base. This knowledge base (drugcombo.info) could help researchers design an efficient phase 1 trial. For example, based on knowledge from Drug Combo, the combination of nivolumab and axitinib did not have potential PK DDI and severe overlapping toxicity. The reviewing physician considered a phase 1b study to start at a curated 5 mg maximum dose of axitinib with dose reduction to 3 and 2 mg and maintenance of a 3-mg/kg dose of nivolumab based on guidelines. With such additional preliminary knowledge, the reviewing statistician felt the adaptive statistical methods could be applied to redesign this phase I combination trial and minimize patient exposure to sub-therapeutic dose levels. Conclusions: To our knowledge, Drug Combo is the first knowledge that integrated curated MTD and DLT knowledge. It would promote applying curated knowledge to better design phase I trials to treat cancer.

Abstract 6573: Drug Combo: A unique resource for efficient phase 1 trial design with manually curated MTD and DLT

Abstract Background: With prior preclinical and clinical knowledge, an effective and efficient cancer drug combinatory trial design could be expected, which will significantly accelerate the translation. However, our internal survey results suggested that some knowledge and data sources were underused or underestimated by researchers. One primary reason is that knowledge of drug combinations is scattered in many distinct databases. Moreover, some essential information, such as MTD and DLT was missed in current databases. Drug Combo (https://drugcombo.shinyapps.io/DrugCombo/) is the first knowledge base that integrates drug toxicity and PK data that may help design an efficient Phase I trial. It is a unique informatics resource that manually curated MTD and DLT are well organized in the knowledgebase. Methods: Drug Combo integrates various publicly available PK and toxicity knowledge for individual drugs and drug combinations (Table 1). More importantly, it is the unique knowledgebase with MTD and DLT. An expert team manually curated MTD and DLT data from publicly available publications. Some standard healthcare terminologies, e.g., Rx-Norm and MedDRA were applied for concept normalization at the back end. We implemented a User-Centered Design process in the user interface (UI).The UI layout will be simple, consistent, purposeful, comprehensive, easy to navigate and informative with readable or scannable typography. A summary view was provided to inform users of some essential information, e.g., MTD, and Overlapping toxicities. The user can find the details in the “Detail Tab”. Results: Currently, Drug Combo integrates pharmacological, pharmacokinetics, and toxicity data. Especially, MTD and DLT data from more than 1,600 published Phase I trials results are exclusive in Drug Combo. Conclusions: Drug Combo is the first knowledge base that provides expert-curated MTD and DLT information. It could help design an effective and efficient drug combination phase 1 trial. Current knowledge type in Drug Combo Type Source Drug Names DrugBank, RxNorm Target DrugBank, Manual curation Associated Condition RxNorm, Drug Labels PK profiles DrugBank Adverse Drug Event Drug Label, FAERS MTD Manual curation DLT Manual curation DDI DrugBank, Manual curation Citation Format: Lei Wang, Shijun Zhang, Lai Wei, Yuxi Zhu, Dwight Owen, Lang Li. Drug Combo: A unique resource for efficient phase 1 trial design with manually curated MTD and DLT [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6573.

Abstract A072: Strategies to improve KRAS G12D inhibitor (MRTX1133) therapy in pancreatic ductal adenocarcinoma

Abstract Background: More than 90% of pancreatic ductal adenocarcinomas (PDAC) harbor oncogenic KRAS, with KRAS G12D being the predominant mutation. Recently, a novel KRAS G12D inhibitor, MRTX-1133, has been developed, potentially revolutionizing PDAC treatment. However, clinical studies on KRAS G12C inhibitors suggest that there may be intrinsic resistance to KRAS inhibitors (KRASi) and acquired resistance can develop rapidly in patients. Moreover, our preliminary data suggest that acquired resistance mechanisms to chemotherapy can also confer partial resistance to KRASi. We hypothesize that effective killing of tumor cells with KRASi will require a rationally designed combinatorial treatment. Methods: We tested chemotherapy and targeted pathway inhibitors which can inhibit signaling upstream and downstream of KRAS to identify drugs that synergize with MRTX-1133. We treated resected human PDAC and mouse tumors from Kras-G12D; P53-R172H; PDX-Cre (KPC) prepared as organotypic slice cultures to test our identified drug combinations. We orthotopically inoculated KPC PDAC cells and treated mice with vehicle, single-agent drugs (MRTX1133 or Afatinib), or combination therapy. We established MRTX-1133-resistant (MRTXR) models in human SUIT2 cells, human organoids and mouse KPC cell lines to study the mechanisms of KRASi resistance. We performed RNA-seq and Reverse Phase Protein Array in these resistance models to identify pathways differentially activated during resistance development. Results: We found that irreversible ErbB inhibitors, Afatinib and Neratinib, had the greatest synergy with MRTX-1133 in parental and in MRTXR cells. We found that combination therapy with MRTX-1133 and Afatinib decreased the number of proliferating cells compared to the control or single-agent treatment in the human and mouse slice cultures. Combination therapy with MRTX1133 and Afatinib significantly reduced tumor growth in mice compared to the vehicle or single-agent controls. We also found that resistant cells demonstrated increased EGFR and HER2 phosphorylation compared to parental cells and that the MRTX-1133 and Afatinib drug combo synergistically decreased EGFR and HER2 phosphorylation. We identified and mapped the differentially expressed pathways and genes involved in KRASi resistance using RNA-seq and RPPA analyses. Conclusion: We identified a likely pathway of resistance to novel KRAS G12D inhibitors, and we demonstrate that this resistance can be effectively targeted using existing therapeutics targeting the ErbB pathway. Citation Format: Kevin Christian M. Gulay, Edgar Esparza, Xinlian Zhang, Evangeline S. Mose, Jonathan Weitz, Minya Pu, Karen Messer, Andrew M. Lowy, Herve Tiriac. Strategies to improve KRAS G12D inhibitor (MRTX1133) therapy in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr A072.

Abstract P229: Treatment And Eradication Of Helicobacter Spp. In TGR(mREN2)27 Transgenic Rat Breeding Colony Does Not Alter Hypertensive Phenotype.

The TGR(mREN2)27, transgenic homozygous (TH) rat strain is severely hypertensive, and unless treated, only 20% of males and 50% of the females survive past 20 weeks of age. Losartan-treated TH male rats are mated with normotensive female Hannover Sprague-Dawley (HnSD) rats to produce less hypertensive hemizygous (HEMI-) TGR(mREN2)27 rats with systolic blood pressure (SBP) ~180-200 mm Hg for females and males at ~20 weeks of age, allowing experimental study without antihypertensive treatment. Helicobacter species infection, which in rodents causes gastro-intestinal and hepatic disturbances and inflammation, compromised immunity and decreased breeding success, was detected in our TH and HnSD breeding colonies. Eradication improves animal health and breeding outcomes. However, the effects of Helicobacter diet treatment on phenotypic characteristics of the HEMI-TGR(mREN2)27 are unknown. TH and HnSD rats from the original WFSM colony were isolated and treated in a clean room for 8-12 weeks with Mouse Diet, Helicobacter 4 Drug Combo (Bio-Serv., Frenchtown, N.J.; pelleted diet containing 3.0 mg Amoxicillin, 0.5 mg Clarithromycin, 1.0 mg Metronidazole, 0.02 mg Omeprazole per 5 grams). Eight male and six female offspring from TH X HnSD rats and five male and six female HnSD X HnSD rats from diet-treated parents with confirmed infection eradication had tail-cuff SBP measured at 20 weeks of age for comparison with rats from the original non-treated colony. The SBPs were similar between control and treated female HEMI-TGR(mREN2)27 (191 ± 8 vs 184 ± 7 mm Hg) and between control and treated male HEMI-TGR(mREN2)27 groups (194 ± 4 vs 182 ± 3 mm Hg). Also, SBP was not different between female or male, control vs treated, HnSD rats (Female: 130 ± 6 vs 121 ± 5 mm Hg; Male:130 ± 1 vs 136 ± 5 mm Hg). Consistent with previous studies, male HEMI-TGR(mREN2)27 rats weighed significantly more than male HnSD rats (516 ± 10 vs 454 ± 16 g, p<0.01), while female mRen and female HnSD were similar (280 ± 8 vs 255 ± 4 g). Therefore, Helicobacter treatment and eradication in homozygous parental TGR and HnSD lines did not alter the hypertensive phenotype in HEMI-TGR(mREN2)27 rats, nor change the normotensive phenotype of HnSD rats.

Multi-component redox system for selective and potent antineoplastic activity towards ovarian cancer cells

Ovarian cancer is the deadliest gynecological cancer which rarely causes symptoms, and goes undetected until reaching the advanced stage of drug-resistant metastases. The cationic porphyrin meso-tetra(4-N-methylpyridyl)porphine (TMPyP) is a well-known photosensitizer (PS) used in photodyamic therapy (PDT) for curing cancer due to its strong affinity for DNA and high yield of reactive oxygen species (ROS) upon light activation. The practicality to irradiate tumor cells alone in the physiological system being slim (due to the close proximity of healthy cells and tumors), we looked for a variation in the PDT using a mixture of TMPyP with 1,5-dihydroxynapthalene (DHN) and Fe(III) ions at a mole ratio of 1:20:17 (drug combo) respectively in aqueous solution. The drug combo needs no photoactivation in H2O2 rich environment (mimicking the microenvironment of cancer/tumor), where it generates ȮH and juglone, the latter being a known potent anticancer agent. In vitro studies of the drug combo in drug resistant and sensitive ovarian cancer cell lines showed drastic growth inhibition and cell death compared to normal epithelial cells. The drug combo provides an effective and non-invasive alternative to conventional PDT, exploiting the cytosolic carcinogenic H2O2 to produce an efficient anticancer treatment. The unique action of cancer-specific cytotoxicity arises from the redox chemistry involving activation of Fe(III) as the oxidizing agent to generate juglone, which utilizes the cytosolic ROS in cancer cells against itself.

Drug Combo Shows Early Potential for Pancreatic Cancer

Drug Combo Shows Early Potential for Pancreatic Cancer

Antioxidant Combo Therapy Protects White Matter After Traumatic Brain Injury.

Following traumatic brain injury (TBI), increased production of reactive oxygen species (ROS) and the ensuing oxidative stress promotes the secondary brain damage that encompasses both grey matter and white matter. As this contributes to the long-term neurological deficits, decreasing oxidative stress during the acute period of TBI is beneficial. While NADPH oxidase (NOX2) is the major producer of ROS, transcription factor Nrf2 that induces antioxidant enzymes promotes efficient ROS disposal. We recently showed that treatment with an antioxidant drug combo of apocynin (NOX2 inhibitor) and TBHQ (Nrf2 activator) protects the grey matter in adult mice subjected to TBI. We currently show that this antioxidant combo therapy given at 2h and 24h after TBI also protects white matter in mouse brain. Thus, the better functional outcomes after TBI in the combo therapy treated mice might be due to a combination of sparing both grey matter and white matter. Hence, the antioxidant combo we tested is a potent therapeutic option for translation in future.

Journal Digest: Autism and Minority Children; Cognitive Bias Training Reduces Alcohol Use; Pandemic Gun Buyers and Suicide; Targeted Therapy Reduces Risk of Youth Depression; Age, Impact of Drug Combo on Weight, Cholesterol

Journal Digest: Autism and Minority Children; Cognitive Bias Training Reduces Alcohol Use; Pandemic Gun Buyers and Suicide; Targeted Therapy Reduces Risk of Youth Depression; Age, Impact of Drug Combo on Weight, Cholesterol

Abstract 5510: Mass-action law based general pharmacodynamics theory and algorithm for quantitative computer simulation of drug-evaluations in cells, in animals and in clinical trials

Abstract The Median-Effect Equation (MEE) for single drug, and the Combination Index Equation (CIE) for multiple drug combinations, are basis for general Pharmacodynamics (PD), and Biodynamics (BD). Both, MEE and CIE are derived from system analysis of the Mass-Action Law (MAL). The MAL-PD/BD theory, equations and algorithms allow automated computer simulations for diagnostic plots and quantitative, digital/indexed conclusions. To date, the MAL dynamic theory is cited over 15,000 times, in over 1,248 biomedical journals. The publications include studies in vitro, in cell, in animal and in clinical trial levels, as indicated in Google Scholar Citations -Ting-Chao Chou, or in Pharmacol. Rev. 58: 621-681, 2006 (cited 3,119 times in 914 journals). MEE indicates dose and effect are interchangeable, and all PD Dose-Effect curves (DEC) can be linearized by the Median-Effect Plot (MEP), x= Log (dose) vs y= Log {(fraction affected (fa)/(fraction unaffected (fu)}, where fa+fu=1, and when fa=fu, gives the Median-Effect Dose (Dm). The slope gives “m” value (dynamic order, signifying the shape of DEC), and the Antilog of x-intercept gives the “Dm” value, (signifying the potency of half-affected, such as IC50, ED50, or LD50). The MEE, is the unified theory of the Michaelis-Menten Eq. for enzyme half-saturation, Handerson-Hasselbalch Eq. for pH half-ionization, Hill Eq. for ligand half-occupancy, and the Scatchard Eq, for receptor half-bond and half-free. Since MEP linearizes the DEC, it requires only a minimum of two data pints to simulate entire DEC. Thus, the Two-Data-Point Theory is extremely cost-effective for animal studies and clinical trial protocol designs, as only small number data points is required to achieve efficient computer simulations, with digital/index conclusions. In CIE, CI<1, =1, and >1, quantitatively defines Synergism, Additive Effect, and Antagonism, respectively, for 2 to n drug combs, using CompuSyn. PD requires multiple doses (3-4 doses in animals; 2-3 doses in clinical trials) since single dose yields a data Point, but “a point” which has “no shape”, thus, it is Not a PD in Vivo. For 2-drug-combos using the CI method in vivo for drug A, B, and A+B, require only 10 data points, (3+3+3 plus one control). Earlier examples with CI method in vivo are: 1. Anti-HIV Combos (AZT+IFN, using only 36 AIDS patients), and 2. Anti-cancer Combos (Taxotere+T607, against HCT-116 colon carcinoma xenograft in nude mice), both used only 10 data points and both achieved quantitative determination of Synergism. This report reaffirm Example 2 with the same drug combos against MX-1 mammary carcinoma xenograft in nude mice, using only 10 data points, showed similar synergy at ED75 to ED97, CI= 0.82-0.79 for MX-1, and CI= 0.98-0.64 for HCT-116. Citation Format: Ting-Chao Chou. Mass-action law based general pharmacodynamics theory and algorithm for quantitative computer simulation of drug-evaluations in cells, in animals and in clinical trials [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5510.

Abstract CT155: General pharmacodynamics algorithm-based clinical protocol design with two to three dose-data points for single-drug, and ten data points for two-drug-combination synergy quantification, using computer simulation for digitalized data analysis and conclusions

Abstract The mass-action law (MAL) based Median-Effect Equation (MEE) for single- drug, and the Combination Index Equation (CIE) for drug-combinations, are the basis for unified Pharmacodynamics (PD) and Biodynamics (BD). To date, the MAL-PD/BD theory, in 3 articles alone, have 12,577 citations in 1,248 biomedical journals (Google Scholar Citation-Ting-Chao Chou). The applications mainly in vitro, relatively few in vivo [see, ChouTC, Pharmacol Rev. 58: 621-681, 2006 (cited 3,301 times in 914 journals) or Synergy 1: 3-21, 2014]. In recent presentations at JHU (4.9.2019) and at FDA (5.7.2019 & 11.7.2019), Chou presented, the PD-based clinical protocol design using 2-3 dose-data points for single-drug, and 10 data points for 2-drug combinations synergy quantification, e.g., A (3), B (3), and A+B (3), at constant combination ratio, plus a control. For the MAL-PD/BD based protocol design in vivo (dose-range and dose density, combination ratio), the automated CompuSyn simulation/quantitative PD-parameters (for potency and PD-shape)/diagnostic plots/digitalized conclusions/and automated print-out report, usually takes a few seconds, and print-out may take 1-2 minutes. All drugs (chemical, biological, radiation) should have a Dose-Effect curves (DEC). The MEE indicates that all PD-DEC can be linearized by the Median-Effect Plot (MEP), x= Log (dose) vs y= Log {(fraction affected (fa)/(fraction unaffected (fu)}, where fa+fu=1, and when fa=fu, gives the Median-Effect Dose (Dm). The slope gives “m” value (signifying the shape of DEC), and the antilog of x-intercept gives the “Dm” value, (signifying the potency of half-affected). Since MEP linearizes the DEC, it requires a minimum of two data pints to simulate entire DEC. Thus, the Two-Data-Point Theory is extremely cost-effective for in vivo clinical trial protocol designs, as only small number data points is required to achieve efficient computer simulations, with digital/index conclusions. In CIE, CI<1, =1, and >1, quantitatively defines Synergism, Additive Effect, and Antagonism, respectively, for 2 to n drug combs, using CompuSyn. PD requires multiple doses since “single dose” yields a data-Point, but “a point” has “no shape”, thus, it is never a PD study. Earlier examples with PD-CI method in vivo are: 1. Anti-HIV Combos (AZT+IFN, using only 36 AIDS patients), and 2. Anti-cancer Combos (Taxotere+T607, against HCT-116 colon carcinoma xenograft in nude mice), both used only 10 data points and both achieved quantitative determination of Synergism. This report reaffirm Example 2 with the same drug combos against MX-1 mammary carcinoma xenograft in nude mice, using only 10 data points, which showed similar synergy at ED75 to ED97, CI= 0.82-0.79 for MX-1, and CI= 0.98-0.64 for HCT-116. In conclusion, the MAL-PD/BD and its equations, algorithms and computer simulation provide a rigorous, cost-effective, automated, quantitative biomedical R and D and general drug evaluation guidance in clinical trial design and data analysis, that save resources, time and efforts. Citation Format: Ting-Chao Chou. General pharmacodynamics algorithm-based clinical protocol design with two to three dose-data points for single-drug, and ten data points for two-drug-combination synergy quantification, using computer simulation for digitalized data analysis and conclusions [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT155.

(Re)conceptualizing “Polydrug Use”: Capturing the Complexity of Combining Substances

The use of multiple psychoactive substances is a widespread phenomenon among people who use drugs. Yet the concept of polydrug use is poorly defined in the social sciences. As a result, theoretical and empirical knowledge of polydrug use is underdeveloped; approaches to measuring polydrug use are inconsistent; and understandings of the cultural meanings of combining substances are limited. This article draws on a collaborative synthesis of three qualitative case studies of polydrug use from four countries: Australia and France, Finland, and Ireland. All three studies explored the practice of substance combination, or “combos” using the lens of intentionality, functionality, and social setting. In addition, the studies shared a common concern with teasing out the rationale for substance combining, and the controls used to balance pleasures with risks, beyond the simple physiological or sensory effects of substances. Our analysis leads us to recommend that a standard definition of polydrug use be adopted for future social science research—that is, the ingestion of two or more substances in combination, at the same time or in temporal proximity, so that the effects of different substances overlap. For analytical purposes, we suggest two subcategories: simultaneous and sequential intake. Moreover, we contend that it is the intention, meaning, and socio-structural context underpinning the use of substance combinations that is central to understanding polydrug use. Consequently, we suggest an adaptation of Zinberg’s seminal concept to one of “drug combo, set, and setting” to incorporate an analysis of the effects of using substances together, or in sequence within a short time frame.

Identification of Novel Synthetic Lethal Partners of NAMPT Inhibitor By CRISPR-Cas9 Screens in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a hematopoietic neoplasm arising from the clonal expansion of myeloid progenitors resulting in bone marrow failure. Nicotinamide phosphoribosyltransferase (NAMPT) is a rate‐limiting enzyme which regulates the generation of the metabolic enzyme substrate NAD+. NAD+ is key in several survival pathways in AML such as DNA repair and metabolic pathways. AML subtypes differ vastly in their inherent DNA repair and metabolic capacities. Since NAMPT is essential in single and double strand DNA repair, NAMPT inhibitors (NAMPTis) were used to block DNA repair as single agents or in combinational therapies in solid tumors. However the clinical experience with the first generation of NAMPTis suggests that higher doses will be needed in order to achieve efficacy, which are associated with high toxicity. We hypothesize that identification of critical synthetic lethal partners for NAMPTi will increase efficacy with lower doses. To this end, we conducted genome-wide CRISPR KO (loss-of-function) screens by using two libraries, GeCKO and Brunello, and identified, along with genes reported essential for AML survival, 16 genes whose knockout displays synergism or resistance, after a NAMPTi (KPT-9274) treatment in AML cells. According to their gene ontology (GO) functions, these co-essential candidates are involved in DNA damage repair and metabolism. Genetic depletion of co-essential genes, SIRT6, HDAC8 and DCPS, sensitizes AML cell lines, MOLM13, Kasumi-1 and MV4-11, to KPT-9274 treatment. In addition, preclinical inhibitor for HDAC8 (PCI-34051), in combination with KPT-9274, synergistically decreased AML primary cell survival in a dose-dependent manner and decreased colony formation in AML patient samples across multiple genotypes with a minimal decrease in colony formation of normal CD34+ hematopoietic cells. In addition, drug combo treatment of AML cells decreased re-plating capacity, implying attenuated self-renewal capacity. Drug combo also increased apoptotic cells as measured by Annexin/PI staining and induced myeloid differentiation as detected by CD45+CD34- staining. In DNA homologous recombination (HR) pathway, SIRT6 and HDAC8 deacetylate CtIP and Rad51 to promote DNA end resection at double strand breaks. Since NAMPT inhibition blocks the generation of NAD+ thus compromising downstream PARP1 mediated base excision repair (BER) as well as the Sirtuin1 (Sirt1) mediated, KU- dependent NHEJ and atypical Rad51-independent HR repair, we expect that inhibiting these HR pathway components (like SIRT6 and HDAC8) may shut down these compensatory repair pathways and sensitize AML subtypes to NAMPT inhibition. Indeed, Western blotting shows drug combo increased acetyl-P53, acetyl-Rad51, phosphor-γH2Ax and Chk1 compared NAMPT inhibition alone. The in vivo efficacy of these combinatorial therapies has been investigated on PDX mouse models established in our laboratory. We demonstrated that the dug combo successfully eliminated engrafted AML cells and conferred survival advantages to mice. Our study provides evidence that co-essential genes, SIRT6, HDAC8 and DCPS, are synthetic lethal partners for NAMPT inhibition to target drug-resistant AML cells, with minimal toxicity towards normal cells. Disclosures Byrd: BeiGene: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; Novartis: Other: Travel Expenses, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Acerta: Research Funding; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Acerta: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; BeiGene: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; Novartis: Other: Travel Expenses, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; Acerta: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau.

Combined Targeting of the Menin-MLL1 Chromatin Complex and FLT3 As a Novel Therapeutic Concept Against NPM1 Mutant or MLL-Rearranged AML with Mutated FLT3

NPM1mutant (NPM1mut) and MLL1-rearranged (MLL-r) acute myeloid leukemias (AMLs) exhibit aberrant expression of HOX and MEIS1 transcription factors and commonly harbor an activating mutation in the receptor tyrosine kinase FLT3. Pharmacologic inhibition of the menin-MLL1 complex reverses leukemogenic gene expression including MEIS1 and FLT3 and represents a therapeutic opportunity for the treatment of these leukemias. Here, we investigate the contribution of the menin-MLL1 complex to leukemic FLT3 signaling and assess the therapeutic potential of dual menin-MLL1 and FLT3 targeting. First, we performed RNA sequencing to delineate transcriptional changes associated with menin-MLL1 inhibition (-i) using the small molecule inhibitor MI503 in NPM1mut and MLL-r AMLs (OCI-AML3 and MV411 cells). In both leukemias, we confirmed MEIS1 and its target gene FLT3 to be among the most significantly downregulated genes. These results were validated in several human cell lines of NPM1mut or MLL-r AMLs and in a genetically engineered murine AML model harboring an NPM1mut and an internal tandem duplication mutation in the FLT3 gene (Npm1mut/+Flt3ITD/+,now referred to as Npm1mutFlt3ITD). Allele-specific qPCR upon MI503 treatment confirmed profound suppression of the FLT3ITD allele present in the MLL-r MV411 and MOLM13 cells. Total FLT3 protein expression was also reduced upon MI503 treatment in all tested NPM1mut and MLL-r AMLs. Next, we assessed the therapeutic potential of combined menin-MLL1-i and FLT3-i in the FLT3-ITD positive MLL-r and NPM1mut leukemias. We found dramatic synergistic growth inhibition and substantially enhanced apoptosis when combining MI503 with the specific small molecule FLT3 inhibitor AC220 (Quizartinib) compared to monotreatment or vehicle control in the FLT3ITD positive MLL-r MV4-11 and MOLM-13 cells. Similar results were obtained when MI503 was combined with other specific FLT3 inhibitors - Crenolanib and Gilteritinib. As the murine Npm1mutFlt3ITD AML cells harbor the Flt3ITD F692L gatekeeper mutation that conveys drug resistance to most FLT3 inhibitors, we used Ponatinib as a combination partner for MI503 in these cells and found similar synergistic suppression of proliferation and colony formation. No drug sensitivity to single or combo treatment was observed in the human HL60 and NB4 cells, or the murine Hoxa9-Meis1 transformed cells (all wildtype for NPM1, MLL, FLT3). To investigate the mechanism of drug synergy we then performed immunoblotting of phosphorylated (activated) FLT3 (pFLT3). As expected, we observed reduced pFLT3 upon direct FLT3 inhibition with AC220 and found decreased total FLT3 and pFLT3 with MI503 monotreatment. Of note, we observed the most pronounced pFLT3 reduction with combo treatment, most likely reflecting the cooperative effect of direct pFLT3 inhibition with AC220 and transcriptional suppression of total FLT3 via MI503. Transcriptional profiling revealed most dramatic reduction of FLT3 downstream signature gene expression including MYC and MYC-dependent genes upon combinatorial treatment compared to single drug or vehicle controls. Ectopic expression of Meis1 or Hoxa9-Meis1 in the Npm1mutFlt3ITD cells led to increased Flt3 gene and protein expression and partially rescued the anti-proliferative effect of MI503 and combined menin-MLL1-i and FLT3-i. Next, we assessed the combo drug regimen in a cell line derived leukemic xenograft murine model in vivo. We found significantly reduced leukemia burden defined by bone marrow engraftment after 14 days of treatment within the combo versus the single drug or vehicle control animals. In a separate experiment, animals that had been treated with the drug combo in vivo had a dramatically enhanced survival compared to the control groups. We then evaluated single and combo drug effects on five primary human NPM1mutFLT3ITD AML patient samples in a human stroma cell co-culture model. The most profound anti-leukemic effect was again detected with the combo treatment compared to all other controls. In summary, we demonstrate synergistic on-target activity against mutant FLT3 signaling with combined menin-MLL1 and FLT3 inhibition in leukemias with NPM1mut or MLL-r in vitro and in vivo. This concept may represent a novel therapeutic opportunity against these AMLs harboring a prognostically adverse FLT3-ITD. Disclosures Vassiliou: Kymab Ltd: Consultancy, Other: Minor Stockholder; Oxstem Ltd: Consultancy; Celgene: Research Funding. Armstrong:Mana Therapeutics: Consultancy, Equity Ownership; Accent Therapeutics: Consultancy, Equity Ownership; OxStem Oncology: Consultancy, Equity Ownership; Syros Pharmaceuticals: Consultancy, Equity Ownership; C4 Therapeutics: Consultancy, Equity Ownership; Cyteir Therapeutics: Consultancy, Equity Ownership; Janssen: Research Funding; Novartis: Research Funding; AstraZeneca: Research Funding; Epizyme, Inc.: Consultancy, Equity Ownership; Imago Biosciences, Inc.: Consultancy, Equity Ownership. Kühn:Pfizer: Consultancy; ABBVIE: Consultancy; Daiichi Sankyo: Other: travel Support; Celgene: Other: travel support.

Drug Combo Heralds Major Shift in Chronic Lymphocytic Leukemia Treatment

Drug Combo Heralds Major Shift in Chronic Lymphocytic Leukemia Treatment

MON-LB064 A Zebra of Adrenal Insufficiency: What Was Once Common Is Now Rare

Background: TB was once a common cause of primary adrenal insufficiency, it is now most often autoimmune in the developed world, but there are rarely observed infectious causes, including TB, Fungal, and CMV. The extra-adrenal manifestations typically stem from pulmonary TB. When TB invades the adrenals, imaging of the adrenal glands initially shows hypertrophy, which progresses to fibrosis and calcification in almost half the cases. This adrenal hypertrophy is often a key marker for differentiating tuberculous adrenal insufficiency from autoimmune adrenalitis, in which case adrenals are usually atrophied. Case: A 62 year old woman with a history of CKD, hyperlipidemia, and possible heart failure presented to the hospital with a 3 week history of worsening right knee pain. She was initially hypotensive at 68/48. Her hospital course was complicated by renal failure, persistent hypotension, and hyponatremia. She received approximately 5 liters of fluid with no significant hemodynamic response. Initial labs showed sodium of 125 with normal range 135-145 and a creatinine of 3.63 with sodium levels hovering in the low 130’s throughout the next 8 days while systolic pressure remained less than 110. Endocrinology was consulted to evaluate the ongoing hypotension and hyponatremia 5 days into admission. Infectious disease was also consulted after it was later revealed that the patient had a history of TB with a positive ppd in 2014, treated with Isoniazid but she was unable to confidently state whether she completed treatment. Other lab work was remarkable for a positive ppd test, negative HIV, and random cortisol levels of 1.3 and 1.1. Cosyntropin stimulation test was very abnormal with cortisol results of 1.3 and 1.1 at 30 and 60 minute intervals (normal >18). ACTH on day 6 of admission was greater than 2000, consistent with primary adrenal insufficiency. Abdominal CT without contrast on day 11 showed adrenal fullness with nodal calcifications consistent with post-infectious TB. Blood pressure and sodium improved on hydrocortisone 50 mg three times daily. She was discharged on hydrocortisone 20mg in the AM and 10mg in the PM, fludrocortisone 0.1mg daily and the 4 drug combo for TB; Rifampin, Isoniazid, Pyrazinamide, and Ethambutol. Conclusion: This case of primary adrenal insufficiency highlights an atypical cause that is now rare in the developed world. TB causes adrenal destruction in a gradual manner, targeting the medulla and cortex secondarily as illustrated here by this HIV-negative latent TB patient. Tuberculous adrenal insufficiency typically presents in an insidious manner. This case demonstrates the importance of a thorough history and evaluation coupled with the realization that not all primary adrenal insufficiency is autoimmune. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Antihypertensive Drug Combos for Black African Patients: A Randomized Trial

Clinicians have flexibility in choosing among drugs for hypertension; sometimes such choices are arbitrary, and sometimes they reflect attempts to

Safety assessment of anticancer drugs in association with radiotherapy in metastatic malignant melanoma: a real-life report : Radiation/systemic drug combo in metastatic melanoma.

To assess the safety of the association of radiotherapy (RT) and systemic treatments for patients with metastatic malignant melanoma (mMM). A retrospective analysis included consecutive patients treated with palliative RT, and at least one line of systemic therapy for mMM between 2001 and 2016. Treatments were defined as sequential or concomitant when RT and the systemic drug were administered, respectively, at more or less than five half-lives from each other. 92 patients were included. They had 110 palliative RT treatments. RT was delivered with a "conventional" chemotherapy (mainly fotemustine and/or dacarbazine) and a "modern" systemic therapy (BRAF inhibitors, association of BRAF and MEK inhibitors, immunotherapy), respectively, in 88 (80%) and 22 (20%) cases. Systemic treatments and RT were mainly concurrently performed (n = 61, 55.5%). Regarding acute grade ≥ 3 toxicity, no difference was reported between sequential and concomitant groups either in the whole cohort (p = 1) or in the subgroup of patients receiving "modern" systemic therapies (p = 1). Acute and late grade ≥ 3 toxicities only occurred with vemurafenib. BRAF inhibitors and RT produced more severe infield adverse events than other associations (p = 0.001) with two deaths. In our series, compared to sequential administration, concomitant association of systemic anticancer drugs and palliative RT did not increase toxicity in mMM patients. BRAF inhibitors and RT produced severe infield toxicities. Prospective studies are needed to better characterize the toxicity of each association.

Drug combo shows promise for treating sleep apnea

Drug combo shows promise for treating sleep apnea