Potent Selective Inhibitor Research Articles

Use of anastrozole in the chemoprevention and treatment of breast cancer: A literature review.

Aromatase inhibitors have emerged as an alternative endocrine therapy for the treatment of hormone sensitive breast cancer in postmenopausal women. The use of third-generation inhibitors represented by exemestane, letrozol and anastrozole is currently indicated. Anastrozole is a nonsteroidal compound and a potent selective inhibitor of the aromatase enzyme. Although a few studies have shown that its pharmacodynamic and pharmacokinetic properties may be affected by interindividual variability, this drug has been recently used in all configurations of breast cancer treatment. In metastatic disease, it is currently considered the first-line treatment for postmenopausal women with estrogen receptor-positive breast tumors. Anastrozole has shown promising results in the adjuvant treatment of early-stage breast cancer in postmenopausal women. It has also achieved interesting results in the chemoprevention of the disease. Therefore, due to the importance of anastrozole both for endocrine treatment and chemoprevention of hormone-sensitive breast cancer in postmenopausal women, we proposed the current literature review in the SciELO and PubMed database of articles published in the last 10 years.

Efficacy of rasagiline for the treatment of Parkinson’s disease: an updated meta-analysis

Objective: Rasagiline is a second-generation potent selective inhibitor of monoamine oxidase-B. The aim of the study was to analyze the effectiveness of rasagiline in treatment of Parkinson’s disease (PD), both as monotherapy and combination therapy.Methods: Medline, Cochrane, EMBASE, and Google Scholar databases were searched until 9 March 2016 using the keywords: Rasagiline, Azilect, Parkinson’s disease. Randomized controlled trials of patients with PD who were randomized to treatment with rasagiline or placebo were included. Outcomes were unified Parkinson’s disease rating scale (UPDRS) and the three subscales.Results: Ten studies fulfilled the inclusion criteria and 2709 patients were evaluated. The overall analysis revealed a significant improvement in change of total UPDRS scores in 1 mg/day and 2 mg/day rasagiline groups compared to placebo. Significant improvement in Part I (Mentation) of UPDRS scores was observed in 1 mg/day, but not in 2 mg/day rasagiline treatment group. Part II (ADL) and Part III (Motor) subscales significantly improved with both doses of rasagiline. Both monotherapy and combination therapy significantly improved total UPDRS scores.Conclusions: Our results confirm the efficacy of rasagiline in PD. Further studies are required to establish the optimal dose of rasagiline, as well as to determine its effectiveness in different combination therapy protocols.KEY MESSAGESRasagiline treatment was associated with significant improvement of UPDRS scores and the scores of the subscales.Both monotherapy and combination therapy significantly improved total UPDRS scores.Effect of rasagiline on total UPDRS scores was not dose-dependent.

Insights from molecular modeling into the selective inhibition of cathepsin S by its inhibitor.

Cathepsin S has been demonstrated to play a crucial role in the remodeling of extracellular matrix proteins such as elastin and collagen, which in turn contribute to the structural integrity of the cardiovascular wall. Atherosclerotic lesions, aneurysm formation, plaque rupture, thrombosis, and calcification are some of the cardiovascular disorders related to cathepsin S. A highly selective inhibitor of human as well as animal cathepsin S, RO5444101, was recently reported to attenuate the progression of atherosclerotic lesions. Here, we attempted to gain insight into the molecular mechanism of action of RO5444101 on cathepsin S by performing molecular docking and molecular dynamics (MD) simulation studies. The results of our studies correlate well with relevant reported experimental data and potentially explain the selectivity of this inhibitor for cathepsin S rather than cathepsin L1/L, cathepsin L2/V, and cathepsin K, which share conserved catalytic sites and have sequence similarities of 49%, 50%, and 55%, respectively, with respect to cathepsin S. In contrast to those closely related cathepsins, 20 ns MD simulation data reveal that the overall interaction of cathepsin S with RO5444101 is more stable and involves more protein-molecule interactions than the interactions of the inhibitor with the other cathepsins. This study therefore considerably improves our understanding of the molecular mechanism responsible for cathepsin S inhibition and facilitates the identification of potential novel selective inhibitors of cathepsin S.

A novel mechanism of diabetic vascular endothelial dysfunction: Hypoadiponectinemia-induced NLRP3 inflammasome activation

It has been well documented that hypoadiponectinemia is associated with impaired endothelium-dependent vasodilation. However, the exact molecular mechanism which mediates this process has not been fully described. The current study aimed to investigate the role of hypoadiponectinemia-induced NLRP3 inflammasome activation in diabetic vascular endothelial dysfunction and its molecular mechanism. Male adult adiponectin knockout mice and wild type mice were fed with a high fat diet to establish a type 2 diabetic mellitus model. In addition, human umbilical vein endothelial cells (HUVECs) were cultured and subjected to high glucose/high fat (HG/HF). The NLRP3 inflammasome activation was increased in type 2 diabetic mice and treatment of diabetic aortic segments with MCC950, a potent selective inhibitor of NLRP3 inflammasome ex vivo improved endothelial-dependent vasorelaxation. NLRP3 inflammasome activation and vascular endothelial injury were significantly increased in APN-KO mice compared with WT mice in diabetes and MCC950 decreased diabetic vascular endothelial dysfunction to comparable levels in APN-KO mice and WT mice. Adiponectin could decrease NLRP3 inflammasome activation and attenuate endothelial cell injury, which was abolished by NLRP3 inflammasome overexpression. Inhibition of peroxynitrite formation preferentially attenuated NLRP3 inflammasome activation in APN-KO diabetic mice. The current study demonstrated for the first time that hypoadiponectinemia-induced NLRP3 inflammasome activation was a novel mechanism of diabetic vascular endothelial dysfunction.

Inhibition of nucleo-cytoplasmic shuttling through XPO1/CRM1: A unique therapeutic approach for treatment of haematological and solid malignancies

Cancer is one of the leading cause of morbidity and mortality worldwide. Regulated nucleo-cytoplasmic shuttling is very crucial for maintaining cellular homeostasis. Emerging evidence suggests that deregulation of the nucleo-cytoplasmic transport results in abnormal cell growth, cell cycle, apoptosis, tumor progression and drug resistance. Exportin-1 (also called as chromosome region maintenance 1) belongs to karyopherin-β superfamily and is the main mediator of nuclear export in several cell types. The XPO1 / CRM1 protein is overexpressed in liposarcoma, Ewing sarcoma, ovarian carcinoma, pancreatic cancer, hepatocellular carcinoma, lung carcinoma, osteosarcoma, gastric carcinoma, melanoma, glioma, acute myeloid leukemia, acute lymphocytic leukemia, chronic myeloid/lymphoid leukemia as well as multiple myeloma. Hot spot mutations were observed in many cancers. Higher levels of XPO1 / CRM1 are associated with poor prognosis, resistance to chemotherapy and recurrence in a large number of human malignancies. There are growing evidence that provided the foundation that inhibition of nuclear export by inhibiting nuclear export receptor ( XPO1 ) might be a potential targeted therapeutic approach for the treatment of human cancers in the clinic. In the present review, we will discuss the role of XPO1 in cancers and potential of selective inhibitors of nuclear export ( XPO1 inhibitors) to restore the normal function of tumor suppressor and growth regulatory proteins by blocking their export. Selinexor (KPT-330) is an orally available, highly potent and is being tested in human phase-I/II clinical trials in both haematological and solid malignancies.

Design, synthesis and evaluation of antiproliferative activity of melanoma-targeted histone deacetylase inhibitors

The clinical validation of histone deacetylase inhibition as a cancer therapeutic modality has stimulated interest in the development of new generation of potent and tumor selective histone deacetylase inhibitors (HDACi). With the goal of selective delivery of the HDACi to melanoma cells, we incorporated the benzamide, a high affinity melanin-binding template, into the design of HDACi to generate a new series of compounds 10a-b and 11a-b which display high potency towards HDAC1 and HDAC6. However, these compounds have attenuated antiproliferative activities relative to the untargeted HDACi. An alternative strategy furnished compound 14, a prodrug bearing the benzamide template linked via a labile bond to a hydroxamate-based HDACi. This pro-drug compound showed promising antiproliferative activity and warrant further study.

Metastatic triple-negative breast cancer is dependent on SphKs/S1P signaling for growth and survival

About 40,000 American women die from metastatic breast cancer each year despite advancements in treatment. Approximately, 15% of breast cancers are triple-negative for estrogen receptor, progesterone receptor, and HER2. Triple-negative cancer is characterized by more aggressive, harder to treat with conventional approaches and having a greater possibility of recurrence. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid signaling mediator has emerged as a key regulatory molecule in breast cancer progression. Therefore, we investigated whether cytosolic sphingosine kinase type 1 (SphK1) and nuclear sphingosine kinase type 2 (SphK2), the enzymes that make S1P are critical for growth and PI3K/AKT, ERK-MAP kinase mediated survival signaling of lung metastatic variant LM2-4 breast cancer cells, generated from the parental triple-negative MDA-MB-231 human breast cancer cell line. Similar with previous report, SphKs/S1P signaling is critical for the growth and survival of estrogen receptor positive MCF-7 human breast cancer cells, was used as our study control. MDA-MB-231 did not show a significant effect of SphKs/S1P signaling on AKT, ERK, and p38 pathways. In contrast, LM2-4 cells that gained lung metastatic phenotype from primary MDA-MB-231 cells show a significant effect of SphKs/S1P signaling requirement on cell growth, survival, and cell motility. PF-543, a selective potent inhibitor of SphK1, attenuated epidermal growth factor (EGF)-mediated cell growth and survival signaling through inhibition of AKT, ERK, and p38 MAP kinase pathways mainly in LM2-4 cells but not in parental MDA-MB-231 human breast cancer cells. Moreover, K-145, a selective inhibitor of SphK2, markedly attenuated EGF-mediated cell growth and survival of LM2-4 cells. We believe this study highlights the importance of SphKs/S1P signaling in metastatic triple-negative breast cancers and targeted therapies.

Multi-step virtual screening to develop selective DYRK1A inhibitors

Developing selective inhibitors for a particular kinase remains a major challenge in kinase-targeted drug discovery. Here we performed a multi-step virtual screening for dual-specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A) inhibitors by focusing on the selectivity for DYRK1A over cyclin-dependent kinase 5 (CDK5). To examine the key factors contributing to the selectivity, we constructed logistic regression models to discriminate between actives and inactives for DYRK1A and CDK5, respectively, using residue-based binding free energies. The residue-based parameters were calculated by molecular mechanics-generalized Born surface area (MM-GBSA) decomposition methods for kinase–ligand complexes modeled by computer ligand docking. Based on the findings from the logistic regression models, we built a three-dimensional (3D) pharmacophore model and chose filter criteria for the multi-step virtual screening. The virtual hit compounds obtained from the screening were assessed for their inhibitory activities against DYRK1A and CDK5 by in vitro assay. Our screening identified two novel selective DYRK1A inhibitors with IC50 values of several μM for DYRK1A and >100μM for CDK5, which can be further optimized to develop more potent selective DYRK1A inhibitors.

Design, synthesis and docking study of novel coumarin ligands as potential selective acetylcholinesterase inhibitors

New coumaryl-thiazole derivatives with the acetamide moiety as a linker between the alkyl chains and/or the heterocycle nucleus were synthesized and in vitro tested as acetylcholinesterase (AChE) inhibitors. 2-(diethylamino)-N-(4-(2-oxo-2H-chromen-3-yl)thiazol-2-yl)acetamide (6c, IC50 value of 43 nM) was the best AChE inhibitor with a selectivity index of 4151.16 over BuChE. Kinetic study of AChE inhibition revealed that 6c was a mixed-type inhibitor. Moreover, the result of H4IIE hepatoma cell toxicity assay for 6c showed negligible cell death. Molecular docking studies were also carried out to clarify the inhibition mode of the more active compounds. Best pose of compound 6c is positioned into the active site with the coumarin ring wedged between the residues of the CAS and catalytic triad of AChE. In addition, the coumarin ring is anchored into the gorge of the enzyme by H-bond with Tyr130.

Regorafenib induces adaptive resistance of colorectal cancer cells via inhibition of vascular endothelial growth factor receptor.

Recently, inhibition of tumor angiogenesis has become an important anti-cancer therapy. Tumor angiogenesis is regulated by multiple signaling pathways, including VEGF and VEGF receptor (VEGF-R), FGF and FGF receptor (FGF-R), and PDGF and PDGF receptor (PDGF-R) pathways. Thus, the antiangiogenic agents, such as regorafenib, simultaneously target those receptors on vascular endothelial cells. In addition to endothelial cells, cancer cells express the three receptors, suggesting that the antiangiogenic inhibitors affect tumor cells. In fact, we previously demonstrated that regorafenib directly acted on human colorectal cancer cells and accelerated their apoptosis resistance and migration capability. Thus, we here elucidated how regorafenib induced the malignant phenotypes in colorectal cancer cells. To identify the responsible receptor among the regorafenib-targeting proangiogenic receptors, we examined the effects of a potent selective inhibitor for VEGF-R, FGF-R or PDGF-R on apoptosis resistance and migration capability. We clarified that blockade of VEGF-R, but not FGF-R and PDGF-R, induced the malignant phenotypes. We confirmed that blocking of VEGF ligands derived from colorectal cancer cells also induced the phenotypes. These results suggest that regorafenib progressed the malignancy via prevention of autocrine and paracrine VEGF signaling in colorectal cancer cells. J. Med. Invest. 64: 262-265, August, 2017.

Brd4 inhibition attenuates unilateral ureteral obstruction-induced fibrosis by blocking TGF-β-mediated Nox4 expression

Uncovering new therapeutic targets for renal fibrosis holds promise for the treatment of chronic kidney diseases. Bromodomain and extra-terminal (BET) protein inhibitors have been shown to effectively ameliorate pathological fibrotic responses. However, the pharmacological effects and underlying mechanisms of these inhibitors in renal fibrosis remain elusive. In this study, we determined that the inhibition of Brd4, a BET family member, with a selective potent chemical inhibitor, JQ1, could prevent the development of renal fibrosis and block the progression of fibrosis in rats that have undergone unilateral ureteral obstruction (UUO). Inhibiting Brd4 with either JQ1 or genetic knockdown resulted in decreased expression of fibrotic genes such as α-smooth muscle actin, collagen IV and fibronectin both in UUO-induced fibrosis and upon TGF-β1 stimulation in HK-2 cells. Brd4 inhibition also suppressed the oxidative stress induced by UUO in vivo or by TGF-β1 in HK-2 cells. Moreover, Nox4, which is constitutively active in renal cells and is involved in the generation of hydrogen peroxide, was up-regulated during UUO-mediated fibrosis and induced by TGF-β1 in HK-2 cells, and this up-regulation could be blunted by Brd4 inhibition. Consistently, Nox4-mediated ROS generation and fibrotic gene expression were attenuated upon Brd4 inhibition. Further, the transcriptional activity of Nox4 was suppressed by JQ1 or siRNA against Brd4. Additionally, Smad3 and ERK1/2 phosphorylation, which are upstream signals of Nox4 expression, were inhibited both in JQ1-administered UUO rats and Brd4-inhibited HK-2 cells. In conclusion, these results indicated that the inhibition of Brd4 might protect against renal fibrosis by blocking the TGF-β-Nox4-ROS-fibrosis axis, suggesting that Brd4 could be a promising therapeutic target.

Ring-opened tetrahydro-γ-carbolines display cytotoxicity and selectivity with histone deacetylase isoforms

This study is focused on modification of the indole moiety and the N1-zinc binding domain of tubastatin A, and the effects of such changes on biological activity. Fourteen N-substituted indoles (5–18) were synthesized and structure-activity relationship studies indicated that the change of the tetrahydro-γ-carboline in tubastatin A led to substituted indoles (compounds 7, 11, and 15) which showed significant improvements of selective inhibition for HDAC6 over HDAC1 and HDAC2 in comparison to ACY1215, a compound undergoing clinical trials. In addition, attachment of different hydroxamic acid groups, the zinc binding motif at the N1 position, contributes to the antiproliferative activity in cancer cells. Several synthetic compounds exhibited potent growth inhibition in a broad spectrum of tumor cell lines, induced irreversible growth arrest capacities by suppressing colony formation ability and activated the apoptosis pathway. The data provide compelling evidence that our newly synthesized compounds with type B to D hydroxamic acid groups as the zinc binding motif at the N1 position are potent selective inhibitors of HDAC6 and could be investigated preclinically as potential anticancer drugs.

Abstract B90: PFK-158 is a first-in-human inhibitor of PFKFB3 that selectively suppresses glucose metabolism of cancer cells and inhibits the immunosuppressive Th17 cells and MDSCs in advanced cancer patients

Abstract Background: 6-phosphofructo-2-kinase (PFKFB3) is an enzyme that controls the intracellular concentration of fructose-2,6-bisphosphate which is an allosteric activator of 6-phosphofructo-1-kinase (PFK-1), a key enzyme of glycolysis. PFK-1 is tightly controlled by multiple metabolic feedback mechanisms and dictates the overall rate of glycolytic flux to lactate and the TCA cycle. In human cancers, several oncogenic proteins (e.g. HIF-1α, PTEN, and AKT) converge to increase the expression and activity of PFKFB3, leading to the high glycolytic rates typically observed in cancer cells. In addition to being a promising cancer metabolism target, PFKFB3 is required for the differentiation and tumor-promoting functions of the immunomodulatory Th17 cells and myeloid derived suppressor cells (MDSCs), which are attractive cellular targets to induce tumor immunity and potentially mediate intrinsic resistance to immune checkpoint inhibitors. PFK-158 is a potent selective small molecule inhibitor of PFKFB3 that displays broad anti-tumor activity causing significant growth inhibition in human and syngeneic preclinical models. As resistance mechanisms frequently activate pathways that result in up-regulation of glycolysis and PFKFB3, combination treatments of PFK-158 with cytotoxic and targeted agents have resulted in increased efficacy and tumor regression. Results: PFK-158 is a potent selective small molecule inhibitor of PFKFB3 that displays broad anti-tumor activity and causes significant growth inhibition in multiple human and syngeneic preclinical models. The tolerability and potential clinical benefit of PFK-158 are being investigated in advanced cancer patients with solid malignancies in a Phase 1 dose-escalation, multi-center clinical trial (clinicaltrials.gov # NCT02044861). The final cohort (650 mg/m2) has been open for enrollment and PFK-158 has been well tolerated to date. Secondary end-points have been incorporated to assess peripheral F2,6BP levels and immunosuppressive and effector cells populations. Of the 15 patients evaluable for response assessment at the end of two months of treatment, 6 patients have experienced a clinical benefit associated with PFK-158 administration, including a late stage pancreatic cancer patient that had a 75% reduction in her CA19-9 levels after 1 month, a renal cell carcinoma patient currently in month 9 and an adenocystic carcinoma patient in month 12. In addition, we examined the immunomodulatory effects of PFK-158 on Th17 cells and MDSCs in vitro, in B16 melanoma-bearing mice and in advanced cancer patients and found that PFK-158: (i) suppresses human Th17 cell and MDSC differentiation in vitro; (ii) decreases splenic and tumor-infiltrating Th17 cells, γδ T17 cells and MDSCs, and increases CD4+ and CD8+ T cells in the tumors of B16-F10 melanoma-bearing mice; and (iii) decreases peripheral blood Th17 cells, γδ T17 cells and MDSCs and increases activated effector CD4+ and CD8+ T cells in advanced cancer patients. Interestingly, we are discerning a correlation between the initial level of circulating Th17 cells and clinical responses to PFK-158. Conclusion: PFK-158 is the first-in-human and first-in-class PFKFB3 inhibitor that is currently under clinical development. To date, PFK-158 has been well tolerated and shows signs of clinical activity. In addition to controlling glycolysis, over expression of PFKFB3 in key immunesuppressive cells also leads to an immunomodulatory mechanism of action, suggesting that additional clinical benefit could result from combining PFK-158 with targeted agents as well as with immunotherapeutic agents. Note: This abstract was not presented at the conference. Citation Format: Sucheta Telang, Kavitha Yaddanapudi, Jaspreet Grewal, Rebecca Redman, Siqing Fu, Paula Pohlmann, Devalingam Mahalingam, Michael Kurman, Gilles Tapolsky, Jason Chesney.{Authors}. PFK-158 is a first-in-human inhibitor of PFKFB3 that selectively suppresses glucose metabolism of cancer cells and inhibits the immunosuppressive Th17 cells and MDSCs in advanced cancer patients. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B90.

Spiro-oxindoles as a Promising Class of Small Molecule Inhibitors of p53-MDM2 Interaction Useful in Targeted Cancer Therapy.

As a result of the toxicity of currently available anticancer drugs and the inefficiency of chemotherapeutic treatments, the design and discovery of effective and selective antitumor agents continues to be a hot topic in organic medicinal chemistry. Targeted therapy is a newer type of cancer treatment that uses drugs designed to interfere with specific molecules necessary for tumor growth and progression. This review explains the mechanism of regulation of p53 (tumor suppressor protein) by MDM2 and illustrates the role of targeting p53-MDM2 protein-protein interaction using small molecules as a new cancer therapeutic strategy. Spirocyclic oxindoles or spiro-oxindoles, with a rigid heterocyclic ring fused at the 3-position of the oxindole core with varied substitution around it, are the most efficacious class of small molecules which inhibit cell proliferation and induce apoptosis in cancer cells, leading to complete tumor growth regression without affecting activities of normal cells. In this review, we present a comprehensive account of the systematic development of and recent progress in diverse spiro-oxindole derivatives active as potent selective inhibitors of p53-MDM2 interaction with special emphasis on spiro-pyrrolidinyl oxindoles (the MI series), their mechanism of action, and structure-activity relationship. This review will help in understanding the molecular mechanism of p53 reactivation by spiro-oxindoles in tumor tissues and also facilitates the design and exploration of more potent analogues with high efficacy and low side effects for the treatment of cancer. Recent progress in spiro-oxindole derivatives as potent small molecule inhibitors of p53-MDM2 interaction, useful as anticancer agents, is described with reference to their mechanism of action and structure-activity relationship.

Hybrid Receptor-Bound/MM-GBSA-Per-residue Energy-Based Pharmacophore Modelling: Enhanced Approach for Identification of Selective LTA4H Inhibitors as Potential Anti-inflammatory Drugs.

Leukotriene A4 hydrolase has been identified as an enzyme with dual anti- and pro-inflammatory role, thus, the conversion of leukotriene to leukotriene B4 in the initiation stage of inflammation and the removal of the chemotactic Pro-Gly-Pro tripeptide. These findings make leukotriene A4 hydrolase an attractive drug target: suggesting an innovative approach towards the identification and design of novel class of compounds that can selectively inhibit leukotriene B4 synthesis while sparing the aminopeptidase activity. Previous inhibitors block the dual activity of the enzyme. Recently, a small lead molecule inhibitor denoted as ARM1 has been identified to block the hydrolase activity of leukotriene A4 hydrolase whilst sparing the aminopeptidase activity. In this study, a hybrid receptor-bound/MM-GBSA-per-residue energy based pharmacophore modeling approach was implemented to identify potential selective hydrolase inhibitors of leukotriene A4 hydrolase. In this approach, active site residues that favorably contributed to the binding of the bound conformation of ARM1 were derived from MD ensembles and MM/GBSA thermodynamic calculations. These residues were then mapped to key pharmacophore features of ARM1. The generated pharmacophore model was used to search the ZINC database for 3D structures that match the pharmacophore. Five new compounds have been identified and proposed as potential epoxide hydrolase selective inhibitors of leukotriene A4 hydrolase. Molecular docking and MM/GBSA analyses revealed that, these top five lead-like compounds ZINC00142747, ZINC94260794, ZINC01382396, ZINC02508448, and ZINC53994447 showed better binding affinities to the hydrolase active site pocket compared to ARM1. Per-residue energy decomposition analysis revealed that amino acid residues Phe314, Tyr378, Pro382, Trp311, Val367, and Ala377 are key residues critical in the selective inhibition of these hits. Information highlighted in this study may guide the the design the next generation of novel and potent epoxide hydrolase selective inhibitors of leukotriene A4 hydrolase.

A Phase 1b, Multi-Center, Open-Label Study of Novel Combinations of CC-122, CC-223, CC-292, and Rituximab in Diffuse Large B-Cell Lymphoma: CC-122-DLBCL-001

A Phase 1b, Multi-Center, Open-Label Study of Novel Combinations of CC-122, CC-223, CC-292, and Rituximab in Diffuse Large B-Cell Lymphoma: CC-122-DLBCL-001

BGB324, an Orally Available Selective Axl Inhibitor Exerts Anti-Leukemic Activity in the First-in-Patient Trial BGBC003 and Induces Unique Changes in Biomarker Profiles

Introduction: The RTK Axl represents a therapeutic target promoting AML cell proliferation and survival by pleiotropic mechanisms. Signalling through Axl is also known to suppress immune reactions mainly by inhibiting pro-inflammatory responses of antigen presenting cells. BGB324 is an orally available selective potent inhibitor of Axl, which is currently being investigated in a Phase 1 a/b trial in AML and MDS. We report here the clinical data and the impact of BGB324 on the Axl signalling pathway. Furthermore, we evaluated the T cell receptor (TCR) repertoire in order to assess potential effects of BGB324 on the immune response in AML patients.Methods: Twenty-five patients (twenty-one with relapsed/refractory AML and four with MDS) were treated in a classical 3+3 dose escalation design. Three dose levels were explored 400/100 mg (loading dose d1-2/maintenance dose), 600/200 mg and 900/300 mg. Serial bone marrow samples (BM) were available from n=5 patients. By means of immunoblotting and ELISA we analyzed phosphorylation of Axl and its downstream targets Erk/MapK and Akt as well as the levels of soluble Axl (sAxl) and osteopontin in plasma. The TCRß repertoire was quantified by Next Generation Sequencing of DNA isolated from peripheral blood MNCs using an Illumina MiSeq sequencer. TCRß gene containing the entire Vß, Dß and Jß segments were amplified with BIOMED2-TCRß-A and -B primer pools. Using genomic DNA as template, the amplicons were tagged with Illumina adapters and indices in two consecutive PCR reactions. Demultiplexing and FastQ formated data output was generated by the MiSeq reporter. Analysis of TCRß data was performed on a Microsoft Cloud using our in-house analysis pipeline Pippa, which relies on MiXCR analysis tools.Results: Treatment was generally well-tolerated. Diarrhea and fatigue represented the most frequent adverse events, which were mostly CTC Grade 1 or 2. One DLT (QTc prolongation) occurred and the MTD has not yet been reached. Steady-state levels of BGB324 were reached between three and six days after initiation of treatment. One AML patient achieved a CRi of 5 months, a second achieved a PR and another achieved clearance of circulating blasts accompanied by peripheral blood count recovery > 3 months (ORR 10%). Four additional AML patients (25%) experienced disease stabilisation for more than four months. Two MDS patients experienced a PR.From the five patients in whom BM samples were available three experienced either an objective response or disease stabilization for more than four months and two had progressive disease. We could detect phosphorylated Axl (pAxl) before treatment and decreased pAxl level after 21 days of treatment in 3 out of 3 responders/patients with SD while could not detect pAxl before treatment in the patients with PD (n=5; p=0.025). The patients with response or SD showed inhibition of pErk and pAxl (2 out of 3) or no change of the activity of these Axl downstream pathways (1 out of 3). The patients with PD showed increased pErk and pAkt level after treatment (n=5; p=0.082).Treatment with BGB324 led to an increase in the levels of sAxl after 21 days of treatment in the plasma of 67% of analyzed patients (n=12). SAxl levels were positively correlated to compound exposure (n=12; r=0.829), indicating that sAxl might be used as a biomarker of target engagement. The highest level of sAxl was seen in the patient who achieved a PR. Osteopontin levels decreased in 67% of analyzed patients after three weeks of treatment with BGB324 indicating modulation of this protein by BGB324. However, there was no correlation between increases of sAxl and decreases of osteopontin in this patient cohort.Interestingly, we could demonstrate diversification of the TCR repertoire by higher abundance of small T cell clones after three weeks of therapy with BGB324 compared to pre-treatment levels in two out of four analysed patients.Conclusion: BGB324 is well tolerated in AML patients and exhibits anti-leukemic activity. BGB324 has on-target activity in AML patients and blocks the phosphorylation of Axl and its downstream pathways. Furthermore, BGB324 can induce a diversification of the TCR repertoire in AML patients and might hold potential as an immune-activating drug. DisclosuresSonja:BergenBio: Honoraria, Other: Travel Support, Research Funding. Gjertsen:BerGenBio AS: Equity Ownership, Membership on an entity’s Board of Directors or advisory committees; Boehringer Ingelheim: Membership on an entity’s Board of Directors or advisory committees; Kinn Therapeutics AS: Equity Ownership. Micklem:BerGenBio AS: Employment, Equity Ownership. Janning:Teva: Honoraria. Fiedler:Pfizer: Research Funding; GSO: Other: Travel; Amgen: Consultancy, Other: Travel, Patents & Royalties, Research Funding; Kolltan: Research Funding; Ariad/Incyte: Consultancy; Novartis: Consultancy; Gilead: Other: Travel; Teva: Other: Travel. Cortes:ARIAD: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Research Funding.

Brain uptake and metabolism of the endocannabinoid anandamide labeled in either the arachidonoyl or ethanolamine moiety

IntroductionAnandamide (N-arachidonoylethanolamine) is a retrograde neuromodulator that activates cannabinoid receptors. The concentration of anandamide in the brain is controlled by fatty acid amide hydrolase (FAAH), which has been the focus of recent drug discovery efforts. Previous studies in C57BL/6 mice using [3H-arachidonoyl]anandamide demonstrated deposition of tritium in thalamus and cortical areas that was blocked by treatment with an FAAH inhibitor and that was not seen in FAAH-knockout mice. This suggested that long chain fatty acid amides radiolabeled in the fatty acid moiety might be useful as ex vivo and in vivo radiotracers for FAAH, since labeled fatty acid released by hydrolysis would be rapidly incorporated into phospholipids with long metabolic turnover periods. MethodsRadiotracers were administered intravenously to conscious Swiss–Webster mice, and radioactivity concentrations in brain areas was quantified and radiolabeled metabolites determined by radiochromatography. Results[14C]Arachidonic acid, [14C-arachidonoyl]anandamide and [14C-ethanolamine]anandamide, and also [14C]myristic acid, [14C-myristoyl]myristoylethanolamine and [14C-ethanolamine]myristoyl-ethanolamine all had very similar distribution patterns, with whole brain radioactivity concentrations of 2–4% injected dose per gram. Pretreatment with the potent selective FAAH inhibitor URB597 did not significantly alter distribution patterns although radiochromatography demonstrated that the rate of incorporation of label from [14C]anandamide into phospholipids was decreased. Pretreatment with the muscarinic agonist arecoline which increases cerebral perfusion increased brain uptake of radiolabel from [14C]arachidonic acid and [14C-ethanolamine]anandamide, and (in dual isotope studies) from the unrelated tracer [125I]RTI-55. ConclusionsTogether with our previously published study with [18F-palmitoyl]16-fluoro-palmitoylethanolamine, the data show that the primary determinant of brain uptake for these tracers in Swiss–Webster mice is initial distribution according to blood flow. It is possible that recently reported strain differences in long chain fatty acid trafficking between C57BL/6 and Swiss–Webster mice are responsible for the differences between our results using [14C]anandamide and the earlier studies using [3H]anandamide.

Design and development of potent and selective factor IXa inhibitors

Clotting factors are important serine proteases present in body regulating both intrinsic and extrinsic pathways of blood coagulation. Factor IX which is also known as Christmas factor which is activated form of factor IXa involved in the intrinsic pathway of coagulation cascade. Factor IXa is a proven target for development of potent selective anticoagulant drug design. On the basis of our previous experience with anticoagulant drug design and binding potential of thiadiazole template within the FIXa active site, development of ten potent selective factors IXa inhibitors were reported. In developed inhibitors modification of the aryl ring on the thiadiazole template was carried out to target S2 and S4 binding site on factor IXa. N-[5-(2-hydroxyphenyl)-1,3,4-thiadiazol-2-yl]-3-[(5-nitropyridin-2-yl)imino]butanamide and N-[5-(4-methylphenyl)-1,3,4-thiadiazol-2-yl]-3-[(5-nitropyridin-2-yl)imino] butanamide are two most potent inhibitors developed having total % inhibition of 78.36 and 76.05 respectively. This strategy of modification of the aryl ring on the thiadiazole template will be successfully employed for development of selective factor IXa inhibitors.

Correction to Design and Synthesis of Highly Potent and Isoform Selective JNK3 Inhibitors: SAR Studies on Aminopyrazole Derivatives.

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to Design and Synthesis of Highly Potent and Isoform Selective JNK3 Inhibitors: SAR Studies on Aminopyrazole DerivativesKe Zheng, Sarah Iqbal, Pamela Hernandez, HaJeung Park, Philip V. LoGrasso*, and Yangbo Feng*Cite this: J. Med. Chem. 2016, 59, 19, 9276Publication Date (Web):September 27, 2016Publication History Published online27 September 2016Published inissue 13 October 2016https://doi.org/10.1021/acs.jmedchem.6b01369Copyright © 2016 American Chemical SocietyRIGHTS & PERMISSIONSACS AuthorChoiceArticle Views708Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (169 KB) Get e-Alerts Get e-Alerts