The Military Health History: An Educational Initiative to Improve Veteran Healthcare

INTRODUCTION

As a result of the nature of military service, veterans are a unique patient population with many special health considerations. For various reasons, measures are often not taken by clinicians to address such special considerations. This results in a healthcare disparity for veterans first described by Dr. Jeffrey Brown in 2012. To address this disparity, we introduced "the military health history" to third-year medical students at a large medical school in the southeastern United States. Our objective was to assess the effectiveness of this educational intervention and determine its potential role in creating a future in which veteran healthcare is of the highest quality.

MATERIALS AND METHODS

This study was approved as a quality assurance/quality improvement project by both Louisiana State University Health Science Center and Southeast Louisiana Veteran Healthcare System IRB offices. A short lecture outlining the components of the military health history was presented to 186 third-year medical students. The students were given the opportunity to answer five survey questions before and after the lecture. These questions assessed the students' current confidence performing a military health history, perceived importance of doing so, and likelihood of future implementation. To determine useful retention of the lecture material, the post-lecture survey was readministered to the same population sample 6 months after the lecture. A series of repeated measures analyses of variance were conducted to examine changes in mean levels of confidence, importance, and likelihood of ascertaining military history during a patient encounter at pre- and post-presentation as well as at the 6 month follow-up.

RESULTS

Results revealed a significant effect of time on importance, Wilks' Lambda = 0.74, F (2, 87) = 15.41, P < 0.001; confidence, Wilks' Lambda = 0.61, F (2, 87) = 27.58, P < 0.001; and likelihood of ascertaining a military history during a future patient encounter, Wilks' Lambda = 0.46, F (2, 88) = 50.58, P < 0.001. Results are demonstrated in detail in Table I of the manuscript.

CONCLUSION

The lecture resulted in a statistically significant increase over 6 months in both the likelihood and confidence parameters. The team believes that this result indicates that the students demonstrated useful retention of the lecture material. Our hope is that these students continue to employ the military health history throughout their years of clinical work. In the future, we plan to survey veterans immediately following Veterans Health Administration clinic visits with members of our study population to assess the patient's perceived benefit of the military health history. The team will continue to investigate ways in which military health curricula can be implemented in undergraduate medical education.

Attitudes of university students towards classroom physical activity breaks in the Netherlands

Background

Regular physical activity has multiple benefits for physical, mental, and psychosocial, however many students do not meet the national physical activity guidelines. Classroom physical activity can help students be more physically active. This study investigated the attitude of university students towards classroom physical activity breaks in a university of applied science setting

Methods

Within this research a mixed methods design have been applied. A online survey was completed by 2016 students an semi-structured interviews were conducted among 19 students.

Results

A total of 2016 students successfully completed the questionnaire with a mean of 18-21 year (67%) and 52 % female. No classroom physical activity breaks were used during the lessons. In addition, almost half of the students are not able to concentrate well during the classes. Students (39%) noticed that physical activity during classes had a positive influence on their concentration. The majority of the students are open to activating forms of teaching at universities of applied sciences (69%). Students have a clear preference for active breaks, curriculum-focused active breaks. Physical activities such as climbing stairs, sports exercises are not students preferred activities.

Conclusions

Implementing classroom physical activity breaks can improve student physical activity and concentration during school and behavior in the classroom. Activities such as climbing stairs, intense aerobic exercise were perceived as inconvenient. Active breaks, curriculum-focused active breaks were acknowledged by students.

Key messages

Keep physical activity breaks short and manageable. Physical activity breaks can help in stress reduction and improving psychological well-being.

Prey for the Proteasome: Targeted Protein Degradation-A Medicinal Chemist's Perspective

Targeted protein degradation (TPD), the ability to control a proteins fate by triggering its degradation in a highly selective and effective manner, has created tremendous excitement in chemical biology and drug discovery within the past decades. The TPD field is spearheaded by small molecule induced protein degradation with molecular glues and proteolysis targeting chimeras (PROTACs) paving the way to expand the druggable space and to create a new paradigm in drug discovery. However, besides the therapeutic angle of TPD a plethora of novel techniques to modulate and control protein levels have been developed. This enables chemical biologists to better understand protein function and to discover and verify new therapeutic targets. This Review gives a comprehensive overview of chemical biology techniques inducing TPD. It explains the strengths and weaknesses of these methods in the context of drug discovery and discusses their future potential from a medicinal chemist's perspective.

Staging and treatment outcomes in oropharyngeal squamous cell carcinoma: a single-centre UK cohort

The 8^th edition of the UICC TNM (UICC 8) staging rules for oropharyngeal squamous cell carcinoma (OPSCC) acknowledges dichotomous disease biology based on the human papillomavirus (HPV) tumour status. This retrospective study was undertaken to validate those staging rules in a single UK treatment centre. Given a recent resurgence of interest in primary surgery for OPSCC, a secondary objective was to identify subsets of patients who might benefit. Patients presenting with OPSCC between 2010 and 2017 to the South Glasgow head and neck multidisciplinary team were identified from a prospective database. Only patients managed with curative intent were included (n=272). Stage group allocation according to the UICC 8 resulted in appropriate hazard discrimination, in contradistinction to the UICC 7 staging rules. Locally advanced (cT3-4) disease had a relatively poor prognosis irrespective of HPV status. No clear benefit for primary surgery in any subgroup was demonstrated. A dichotomous disease biology based on the HPV status of tumour is confirmed in this cohort. Patients with HPV-positive T1 and T2 primary tumours have an excellent prognosis when treated with non-surgical treatment regimens. The use of surgery as the primary management for categories of patients presenting with OPSCC should be in the context of clinical trials.

Treating Cancer by Spindle Assembly Checkpoint Abrogation: Discovery of Two Clinical Candidates, BAY 1161909 and BAY 1217389, Targeting MPS1 Kinase

Inhibition of monopolar spindle 1 (MPS1) kinase represents a novel approach to cancer treatment: instead of arresting the cell cycle in tumor cells, cells are driven into mitosis irrespective of DNA damage and unattached/misattached chromosomes, resulting in aneuploidy and cell death. Starting points for our optimization efforts with the goal to identify MPS1 inhibitors were two HTS hits from the distinct chemical series "triazolopyridines" and "imidazopyrazines". The major initial issue of the triazolopyridine series was the moderate potency of the HTS hits. The imidazopyrazine series displayed more than 10-fold higher potencies; however, in the early project phase, this series suffered from poor metabolic stability. Here, we outline the evolution of the two hit series to clinical candidates BAY 1161909 and BAY 1217389 and reveal how both clinical candidates bind to the ATP site of MPS1 kinase, while addressing different pockets utilizing different binding interactions, along with their synthesis and preclinical characterization in selected in vivo efficacy models.

Synergistic Effect of a HER2 Targeted Thorium-227 Conjugate in Combination with Olaparib in a BRCA2 Deficient Xenograft Model

Targeted thorium-227 conjugates (TTCs) represent a novel class of therapeutic radiopharmaceuticals for the treatment of cancer. TTCs consist of the alpha particle emitter thorium-227 complexed to a 3,2-hydroxypyridinone chelator conjugated to a tumor-targeting monoclonal antibody. The high energy and short range of the alpha particles induce potent and selective anti-tumor activity driven by the induction of DNA damage in the target cell. Methods: The efficacy of human epidermal growth factor receptor 2 (HER2)-TTC was tested in combination in vitro and in vivo with the poly ADP ribose polymerase (PARP) inhibitor (PARPi), olaparib, in the human colorectal adenocarcinoma isogenic cell line pair DLD-1 and the knockout variant DLD-1 BRCA2 -/- Results: The in vitro combination effects were determined to be synergistic in DLD-1 BRCA2 -/- and additive in DLD-1 parental cell lines. Similarly, the in vivo efficacy of the combination was determined to be synergistic only in the DLD-1 BRCA2 -/- xenograft model, with statistically significant tumor growth inhibition at a single TTC dose of 120 kBq/kg body weight (bw) and 50 mg/kg bw olaparib (daily, i.p. for 4 weeks), demonstrating comparable tumor growth inhibition to a single TTC dose of 600 kBq/kg bw. Conclusions: This study supports the further investigation of DNA damage response inhibitors in combination with TTCs as a new strategy for the effective treatment of mutation-associated cancers.

The Novel ATR Inhibitor BAY 1895344 Is Efficacious as Monotherapy and Combined with DNA Damage-Inducing or Repair-Compromising Therapies in Preclinical Cancer Models

The DNA damage response (DDR) secures the integrity of the genome of eukaryotic cells. DDR deficiencies can promote tumorigenesis but concurrently may increase dependence on alternative repair pathways. The ataxia telangiectasia and Rad3-related (ATR) kinase plays a central role in the DDR by activating essential signaling pathways of DNA damage repair. Here, we studied the effect of the novel selective ATR kinase inhibitor BAY 1895344 on tumor cell growth and viability. Potent antiproliferative activity was demonstrated in a broad spectrum of human tumor cell lines. BAY 1895344 exhibited strong monotherapy efficacy in cancer xenograft models that carry DNA damage repair deficiencies. The combination of BAY 1895344 with DNA damage-inducing chemotherapy or external beam radiotherapy (EBRT) showed synergistic antitumor activity. Combination treatment with BAY 1895344 and DDR inhibitors achieved strong synergistic antiproliferative activity in vitro, and combined inhibition of ATR and PARP signaling using olaparib demonstrated synergistic antitumor activity in vivo Furthermore, the combination of BAY 1895344 with the novel, nonsteroidal androgen receptor antagonist darolutamide resulted in significantly improved antitumor efficacy compared with respective single-agent treatments in hormone-dependent prostate cancer, and addition of EBRT resulted in even further enhanced antitumor efficacy. Thus, the ATR inhibitor BAY 1895344 may provide new therapeutic options for the treatment of cancers with certain DDR deficiencies in monotherapy and in combination with DNA damage-inducing or DNA repair-compromising cancer therapies by improving their efficacy.

A basic solution to activate the cholinergic anti-inflammatory pathway via the mesothelium?

Much research now indicates that vagal nerve stimulation results in a systemic reduction in inflammatory cytokine production and an increase in anti-inflammatory cell populations that originates from the spleen. Termed the 'cholinergic anti-inflammatory pathway', therapeutic activation of this innate physiological response holds enormous promise for the treatment of inflammatory disease. Much controversy remains however, regarding the underlying physiological pathways mediating this response. This controversy is anchored in the fact that the vagal nerve itself does not innervate the spleen. Recent research from our own laboratory indicating that oral intake of sodium bicarbonate stimulates splenic anti-inflammatory pathways, and that this effect may require transmission of signals to the spleen through the mesothelium, provide new insight into the physiological pathways mediating the cholinergic anti-inflammatory pathway. In this review, we examine proposed models of the cholinergic anti-inflammatory pathway and attempt to frame our recent results in relation to these hypotheses. Following this discussion, we then provide an alternative model of the cholinergic anti-inflammatory pathway which is consistent both with our recent findings and the published literature. We then discuss experimental approaches that may be useful to delineate these hypotheses. We believe the outcome of these experiments will be critical in identifying the most appropriate methods to harness the therapeutic potential of the cholinergic anti-inflammatory pathway for the treatment of disease and may also shed light on the etiology of other pathologies, such as idiopathic fibrosis.

Inhibition of BUB1 Kinase by BAY 1816032 Sensitizes Tumor Cells toward Taxanes, ATR, and PARP Inhibitors In Vitro and In Vivo

PURPOSE

The catalytic function of BUB1 is required for chromosome arm resolution and positioning of the chromosomal passenger complex for resolution of spindle attachment errors and plays only a minor role in spindle assembly checkpoint activation. Here, we present the identification and preclinical pharmacologic profile of the first BUB1 kinase inhibitor with good bioavailability.

EXPERIMENTAL DESIGN

The Bayer compound library was screened for BUB1 kinase inhibitors and medicinal chemistry efforts to improve target affinity and physicochemical and pharmacokinetic parameters resulting in the identification of BAY 1816032 were performed. BAY 1816032 was characterized for kinase selectivity, inhibition of BUB1 signaling, and inhibition of tumor cell proliferation alone and in combination with taxanes, ATR, and PARP inhibitors. Effects on tumor growth in vivo were evaluated using human triple-negative breast xenograft models.

RESULTS

The highly selective compound BAY 1816032 showed long target residence time and induced chromosome mis-segregation upon combination with low concentrations of paclitaxel. It was synergistic or additive in combination with paclitaxel or docetaxel, as well as with ATR or PARP inhibitors in cellular assays. Tumor xenograft studies demonstrated a strong and statistically significant reduction of tumor size and excellent tolerability upon combination of BAY 1816032 with paclitaxel or olaparib as compared with the respective monotherapies.

CONCLUSIONS

Our findings suggest clinical proof-of-concept studies evaluating BAY 1816032 in combination with taxanes or PARP inhibitors to enhance their efficacy and potentially overcome resistance.

Binding Kinetics Survey of the Drugged Kinome

Target residence time is emerging as an important optimization parameter in drug discovery, yet target and off-target engagement dynamics have not been clearly linked to the clinical performance of drugs. Here we developed high-throughput binding kinetics assays to characterize the interactions of 270 protein kinase inhibitors with 40 clinically relevant targets. Analysis of the results revealed that on-rates are better correlated with affinity than off-rates and that the fraction of slowly dissociating drug-target complexes increases from early/preclinical to late stage and FDA-approved compounds, suggesting distinct contributions by each parameter to clinical success. Combining binding parameters with PK/ADME properties, we illustrate in silico and in cells how kinetic selectivity could be exploited as an optimization strategy. Furthermore, using bio- and chemoinformatics we uncovered structural features influencing rate constants. Our results underscore the value of binding kinetics information in rational drug design and provide a resource for future studies on this subject.

Abstract 1887: Preclinical evaluation of a novel interleukin-1 receptor-associated kinase 4 (IRAK4) inhibitor in combination with PI3K inhibitor copanlisib or BTK inhibitors in ABC-DLBCL

Activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL) is frequently characterized by aberrant activation of both B-Cell Receptor (BCR) & TLR/MYD88 signaling pathways. Constitutive BCR signaling via Bruton's tyrosine kinase (BTK) and PI3K pathways leads to downstream activation of NF-κB and AKT signaling. In addition, IRAK4 mediated activation of the TLR/MYD88 pathway further activates NF-κB signaling and pro-survival pathways. Simultaneous blockade of TLR/MYD88 signaling via IRAK4 inhibition in combination with pharmacological blockade of PI3K/BCR signaling pathways may therefore provide a novel treatment strategy in ABC-DLBCL.

BAY 1830839 is a novel small molecule inhibitor of IRAK4 identified by a medicinal chemistry optimization program. Key features of the compound are high potency (IC50 of 3 nM) in a biochemical assay, excellent kinase selectivity and a good overall PK profile making the compound a valuable tool for in vivo studies.

In vitro, treatment of IRAK4 inhibitor BAY 1830839 in combination with BTK inhibitors or copanlisib, a pan class I PI3K inhibitor with predominant activity towards PI3Kα and PI3Kδ, synergistically inhibited NF-κB activation and cell viability in human ABC-DLBCL cell lines. In vivo, IRAK4 inhibition alone did not exhibit anti-tumor effects but in combination treatment with ibrutinib, a covalent inhibitor of BTK, synergistic anti-tumor activity with significantly improved efficacy over ibrutinib monotherapy was observed in the human ABC-DLBCL xenograft models TMD-8 and OCI-LY10 (MYD88mut/CD79A/Bmut). Moreover, IRAK4 inhibitor BAY 1830839 showed synergistic anti-tumor activity in combination with copanlisib with significant improvement of copanlisib monotherapy efficacy in the ABC-DLBCL PDX models LY2988 and LY2266 (MYD88mut/CD79A/Bmut and MYD88wt/CD79A/Bwt, respectively). In addition, the combination of IRAK4 inhibition with pharmacological blockade of PI3K-/ BCR signaling led to reduced activity of the downstream pro-survival STAT3 pathway and IL-6/IL-10 production as detected in tumor xenografts, validating our biological rationale and the expected mechanism of action.

In summary, IRAK4 inhibition in combination with pharmacological blockade of PI3K or BCR signaling blocks pro-survival NF-κB & JAK-STAT pathway activation and subsequent IL-6/IL-10 production. Enhancing activity of clinically used PI3K or BTK inhibitors by combination with IRAK4 inhibition indicates a potential new treatment approach for ABC-DLBCL patients progressing on Standard of Care therapy.

Citation Format: Martin Lange, Antje Margret Wengner, Ulrich Bothe, Ulf Boemer, Reinhard Nubbemeyer, Holger Siebeneicher, Holger Steuber, Judith Guenther, Lisette Potze, Nicole Schmidt, Oliver Politz, Wolf-Dietrich Doecke, Eleni Lagkadinou, Thomas M. Zollner, Franz von Nussbaum, Dominik Mumberg, Andreas Steinmeyer, Michael Brands, Karl Ziegelbauer. Preclinical evaluation of a novel interleukin-1 receptor-associated kinase 4 (IRAK4) inhibitor in combination with PI3K inhibitor copanlisib or BTK inhibitors in ABC-DLBCL [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1887.

Influence of prednisolone on parameters of de novo lipogenesis and indices for stearoyl-CoA- and Δ6- desaturase activity in healthy males: A Post-hoc analysis of a randomized, placebo-controlled, double-blind trial

Glucocorticoid treatment decreases liver insulin sensitivity and may modify fatty acid metabolism. We investigated the influence of oral prednisolone on indices for de novo lipogenesis (DNLi), stearoyl-CoA desaturase (SCDi) and Δ6-desaturase (D6Di) activity in healthy males. In addition, we explored whether the changes may be associated with prednisolone-induced changes in glucose and lipid metabolism and insulin sensitivity. Thirty-two healthy young males (mean ± SD age 22 ± 3 years, BMI 22.4 ± 1.7 kg/m²) were allocated to receive prednisolone 7.5 mg/day (PRED7.5; n = 12), prednisolone 30 mg/day (PRED30; n = 12), or placebo (n = 8) in a randomized double-blind fashion for 2 weeks. Fatty acid compositions of plasma cholesteryl esters (CE), phospholipids (PL) and triglycerides (TG) were measured at baseline and on day 14. DNLi, SCDi and D6Di were estimated from product/precursor ratios in CE, with DNLi primary deriving from 16:1ω7/18:2ω6, SCDi from 16:1ω7/16:0 and D6Di from 22:6ω3/20:5ω3. Ratios were also assessed in PL and TG. In CE, PRED30 increased DNLi by 51.2 [95%CI 14.8; 87.6]%, increased SCDi by 48.6 [18.7; 78.5]%, and decreased D6Di by 57.7 [-91.8; -23.5]% (p ≤ 0.01 for all, compared to placebo). The prednisolone-induced increases in DNLi and SCDi were positively correlated with insulin sensitivity (r = 0.35 and 0.50, respectively). Similar results were found in PL and TG. Prednisolone dose-dependently increases DNLi and SCDi and decreases D6Di in plasma CE, PL and TG in healthy males after 2 weeks. The observed unfavorable effects on fatty acid metabolism were related to the induction of glucocorticoid-induced insulin resistance.

Identification of Atuveciclib (BAY 1143572), the First Highly Selective, Clinical PTEFb/CDK9 Inhibitor for the Treatment of Cancer

Selective inhibition of exclusively transcription‐regulating PTEFb/CDK9 is a promising new approach in cancer therapy. Starting from lead compound BAY‐958, lead optimization efforts strictly focusing on kinase selectivity, physicochemical and DMPK properties finally led to the identification of the orally available clinical candidate atuveciclib (BAY 1143572). Structurally characterized by an unusual benzyl sulfoximine group, BAY 1143572 exhibited the best overall profile in vitro and in vivo, including high efficacy and good tolerability in xenograft models in mice and rats. BAY 1143572 is the first potent and highly selective PTEFb/CDK9 inhibitor to enter clinical trials for the treatment of cancer.

Abstract 836: ATR inhibitor BAY 1895344 shows potent anti-tumor efficacy in monotherapy and strong combination potential with the targeted alpha therapy Radium-223 dichloride in preclinical tumor models

The integrity of the genome of eukaryotic cells is secured by complex signaling pathways, known as DNA damage response (DDR). Recognition of DNA damage activates DDR pathways resulting in cell cycle arrest, induction of DNA repair, or cell death. Proteins that directly recognize aberrant DNA structures recruit and activate kinases of the DDR pathway, such as ATR (ataxia telangiectasia and Rad3-related). ATR responds to a broad spectrum of DNA damage, including double-strand breaks (DSB) and lesions derived from interference with DNA replication as well as increased replication stress. Therefore, inhibition of ATR kinase activity could be the basis for a novel anti-cancer therapy in tumors with increased DNA damage, deficiency in DNA damage repair or replication stress. Radium-223 dichloride (Xofigo®) is the first and only approved targeted alpha therapy so far. It is indicated for the treatment of patients with castration-resistant prostate cancer (CRPC), symptomatic bone metastases and no known visceral metastatic disease, based on improvement of overall survival. It exhibits strong cytotoxic effects on adjacent cells via the induction of DNA DSB.

Here, we disclose for the first time the structure and functional characterization of the novel ATR kinase inhibitor BAY 1895344. In vitro, BAY 1895344 is a selective low-nanomolar inhibitor of ATR kinase activity, potently inhibiting proliferation of a broad spectrum of human tumor cell lines (median IC50 of 78 nM). A clear separation between highly sensitive (IC50 &lt;10 nM) and less sensitive cell lines was observed. The majority of the sensitive cell lines are characterized by mutations affecting the ATM (ataxia telangiectasia mutated) pathway. In cellular mechanistic assays BAY 1895344 inhibited hydroxyurea-induced H2AX phosphorylation demonstrating the anticipated mode of action. BAY 1895344 is an ATR inhibitor that exhibits strong in vivo anti-tumor efficacy in monotherapy in a variety of xenograft models of different indications that are characterized by DDR deficiencies, inducing stable disease in ovarian and colorectal cancer or even complete tumor remission in mantle cell lymphoma models. In addition, we could demonstrate that combination treatment with BAY 1895344 and Radium-223 exhibits clear synergistic anti-tumor activity in a bone metastases xenograft model of CRPC.

Our findings validate the concept of synthetic lethality of genetically determined DNA repair deficiency and ATR blockade by demonstrating strong monotherapy efficacy of the highly potent ATR inhibitor BAY 1895344 in a variety of tumor indications. Furthermore, the mechanism-based combination potential of DNA damage induction by Radium-223 with BAY 1895344 creates a powerful new treatment option for CRPC patients with bone metastases.

The start of clinical investigation of BAY 1895344 is planned early 2017.

Citation Format: Antje Margret Wengner, Gerhard Siemeister, Ulrich Luecking, Julien Lefranc, Philip Lienau, Gesa Deeg, Eleni Lagkadinou, Li Liu, Sven Golfier, Christoph Schatz, Arne Scholz, Franz von Nussbaum, Michael Brands, Dominik Mumberg, Karl Ziegelbauer. ATR inhibitor BAY 1895344 shows potent anti-tumor efficacy in monotherapy and strong combination potential with the targeted alpha therapy Radium-223 dichloride in preclinical tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 836. doi:10.1158/1538-7445.AM2017-836

Abstract 160: High target binding affinity with long lasting cellular target engagement and high dose intermittent schedule of PI3K inhibitor copanlisib contribute to the potent anti-tumor activity and good safety profile

Introduction: Several generations of PI3K inhibitors have been tested in clinic. However, thus far, clinical activity has been moderate. Different from other oral PI3K inhibitors dosed continuously, copanlisib (BAY 80-6946) is an intravenous PI3K inhibitor given intermittently to patients. Copanlisib dosed once weekly demonstrated clinical benefit with an improved safety profile, and therefore challenges the concept of default continuous dosing of PI3K inhibitors. However, it is still unclear if this concept can be generalized and whether ‘micropharmacokinetic parameters’ also contributed to the potent anti-tumor profile of copanlisib. Here, we report the characterization of binding kinetics for copanlisib, as well as the functional consequence in vivo.

Methods: A set of PI3K inhibitors were characterized in 1) a kinetic probe competition assay (kPCA); 2) a cellular nanoBRET target engagement assay; 3) a cellular washout study with the assessment on pathway engagement; and 4) in vivo pharmacokinetics analysis.

Results: Copanlisib showed nearly diffusion-controlled on- and relatively slow off-rates with kon = 3.45E+7 [M-1*s-1] and koff = 1.67E-3 [s-1] to PI3Kα. Consequently, it exhibited very high affinity to PI3Kα ( Ki ePCA = 9.31E-11[M] and KD kPCA = 4.77E-11 [M]). In a cellular nanoBRET target engagement assay, the apparent half-life (t1/2) of ca. 2 hours greatly surpassed the 6.9 min measured using kPCA. The high affinity to PI3Kα also translated into potent cellular pathway engagement demonstrated by inhibition of p-AKT and p-PRAS40 in the PIK3CAmut KPL4 cell line. In a cellular washout study, p-AKT and p-PRAS40 were assessed till 168 h after incubation with copanlisib for 1 h followed by a washout step. A dose- and time-dependent pathway engagement was observed even at 72 h post washout. This result indicated that in cells, copanlisib engages PI3Kα for an extremely long time, likely due to rebinding effects facilitated by the fast equilibration kinetics of the compound and its micropharmacokinetic properties. Interestingly, in vivo, BAY 80-6946 levels were approximately 100-fold higher in the tumor than in plasma at 48 hours and drug clearance from the tumor occurred more slowly than from plasma. This high and prolonged tumor exposure might be explained, at least in part, by the high expression of PI3Kα and long lasting target occupancy of copanlisib in tumors.

Conclusion: Copanlisib demonstrated high affinity to PI3Kα with protracted target engagement at cellular and in vivo levels. This ‘micropharmacokinetic feature’ not only supports intermittent dosing but likely also explains the high exposure in tumors vs plasma, potent anti-tumor activity and good safety profiles.

Citation Format: Amaury E. Fernández-Montalván, Victoria Georgi, James Vasta, Sarah Glaeske, Vera Puetter, Matthew B. Robers, Ursula Moenning, Andrea Sturz, Julien Lefranc, Karl Ziegelbauer, Michael Brands, Christian Stegmann, William J. Scott, Ningshu Liu. High target binding affinity with long lasting cellular target engagement and high dose intermittent schedule of PI3K inhibitor copanlisib contribute to the potent anti-tumor activity and good safety profile [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 160. doi:10.1158/1538-7445.AM2017-160

Abstract 287: BAY 1816032, a novel BUB1 kinase inhibitor with potent antitumor activity

The spindle assembly checkpoint represents a highly conserved surveillance mechanism which safeguards correct chromosome segregation by delaying anaphase onset until all chromosomes are properly bi-oriented on the spindle apparatus. Non-catalytic functions of the mitotic kinase BUB1 (budding uninhibited by benzimidazoles 1) were reported to be essential for spindle assembly checkpoint activation. In contrast, the catalytic function of BUB1 plays a minor role in spindle assembly checkpoint activation but is required for chromosome arm resolution and positioning of the chromosomal passenger complex for resolution of spindle attachment errors. Here, we disclose for the first time the structure and functional characterization of a novel, first-in-class Bub1 kinase inhibitor. Medicinal chemistry efforts resulted in BAY 1816032 featuring high potency, long target residence time and good oral bioavailablity. It inhibits BUB1 enzymatic activity with an IC50 of 7 nanomol/L, shows slow dissociation kinetics resulting in a long target residence time of 87 min, and an excellent selectivity on a panel of 395 kinases. Mechanistically BAY 1816032 abrogated nocodazole-induced Thr-120 phosphorylation of the major BUB1 target protein histone H2A in HeLa cells with an IC50 of 29 nanomol/L, induced lagging chromosomes and mitotic delay. Persistent lagging chromosomes and missegregation were observed upon combination with low concentrations of paclitaxel. Single agent BAY 1816032 inhibited proliferation of various tumor cell lines with a median IC50 of 1.4 micromol/L and demonstrated synergy or additivity with paclitaxel or docetaxel in almost all cell lines evaluated (minimal combination index 0.3). In tumor xenograft studies BAY 1816032 only marginally inhibited tumor growth as single agent upon oral administration, however, upon combination with paclitaxel or docetaxel a strong and statistically significant reduction of tumor size as compared to the respective monotherapy was observed. Intratumoral levels of phospho-Thr120 H2A were found to be strongly reduced, and no hints on drug-drug interactions were found. In line with the good tolerability in xenograft studies, no relevant findings from non-GLP 2 weeks toxicological studies in rat and dog were reported. Our findings validate the innovative concept of interference with mitotic checkpoints and justify clinical proof of concept studies evaluating BUB1 inhibitor BAY 1816032 in combination with taxanes in order to enhance their efficacy and potentially overcome resistance.

Citation Format: Gerhard Siemeister, Anne Mengel, Wilhelm Bone, Jens Schröder, Sabine Zitzmann-Kolbe, Hans Briem, Amaury E. Fernández-Montalván, Simon Holton, Ursula Mönning, Oliver von Ahsen, Sandra Johanssen, Arwed Cleve, Marion Hitchcock, Kirstin Meyer, Franz von Nussbaum, Michael Brands, Dominik Mumberg, Karl Ziegelbauer. BAY 1816032, a novel BUB1 kinase inhibitor with potent antitumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 287. doi:10.1158/1538-7445.AM2017-287

Abstract 4332: Discovery of BAY 1163877 - A pan-FGFR inhibitor: De novo structure-based design and lead optimization of benzothiophenyl-pyrrolotriazines

Fibroblast growth factors (FGFs) orchestrate a variety of cellular functions by binding to their transmembrane tyrosine-kinase receptors (FGFR1-4) and activating downstream signaling pathways. Alterations in FGFR encoding genes are frequently observed in a variety of solid tumors including lung, gastric, breast and urothelial cancer. Therefore, targeting FGFRs using selective FGFR inhibitors is an attractive therapeutic approach to treat cancer patients.

BAY 1163877 is an orally active, highly potent and selective small molecule FGFR-1, -2 and -3 kinase inhibitor. We disclose for the very first time its discovery and chemical structure. BAY 1163877 was derived from a de novo structure-based design approach and medicinal chemistry optimization. Data on the structure activity relationship and the pharmacokinetic profile of the benzothiophenyl-pyrrolotriazine structure class will be presented. Based on its favorable preclinical profile, BAY 1163877 is currently being investigated in a Phase 1 clinical trial (NCT01976741).

Citation Format: Marie-Pierre L. Collin, Mario Lobell, Walter Huebsch, Dirk Brohm, Mélanie Héroult, Klemens Lustig, Sylvia Gruenewald, Ulf Boemer, Rolf Jautelat, Holger Hess-Stump, Stefan Jaroch, Michael Brands, Karl Ziegelbauer. Discovery of BAY 1163877 - A pan-FGFR inhibitor: De novo structure-based design and lead optimization of benzothiophenyl-pyrrolotriazines. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4332.

Discovery and SAR of Novel 2,3-Dihydroimidazo[1,2-c]quinazoline PI3K Inhibitors: Identification of Copanlisib (BAY 80-6946)

The phosphoinositide 3‐kinase (PI3K) pathway is aberrantly activated in many disease states, including tumor cells, either by growth factor receptor tyrosine kinases or by the genetic mutation and amplification of key pathway components. A variety of PI3K isoforms play differential roles in cancers. As such, the development of PI3K inhibitors from novel compound classes should lead to differential pharmacological and pharmacokinetic profiles and allow exploration in various indications, combinations, and dosing regimens. A screening effort aimed at the identification of PI3Kγ inhibitors for the treatment of inflammatory diseases led to the discovery of the novel 2,3‐dihydroimidazo[1,2‐c]quinazoline class of PI3K inhibitors. A subsequent lead optimization program targeting cancer therapy focused on inhibition of PI3Kα and PI3Kβ. Herein, initial structure–activity relationship findings for this class and the optimization that led to the identification of copanlisib (BAY 80‐6946) as a clinical candidate for the treatment of solid and hematological tumors are described.

BAY 1024767 blocks androgen receptor mutants found in castration-resistant prostate cancer patients

Androgen receptor (AR) mutations arise in patients developing resistance to hormone deprivation therapies. Here we describe BAY 1024767, a thiohydantoin derivative with strong antagonistic activity against nine AR variants with mutations located in the AR ligand-binding domain (LBD), and against wild-type AR. Antagonism was maintained, though reduced, at increased androgen levels. Anti-tumor efficacy was evidenced in vivo in the KuCaP-1 prostate cancer model which bears the W741C bicalutamide resistance mutation and in the syngeneic prostate cancer rat model Dunning R3327-G. The prevalence of six selected AR mutations was determined in plasma DNA originating from 100 resistant patients and found to be at least 12%. Altogether the results show BAY 1024767 to be a strong antagonist for several AR mutants linked to therapy resistance, which opens the door for next-generation compounds that can benefit patients based on their mutation profile.

Novel Mps1 Kinase Inhibitors with Potent Antitumor Activity

Monopolar spindle 1 (Mps1) has been shown to function as the key kinase that activates the spindle assembly checkpoint (SAC) to secure proper distribution of chromosomes to daughter cells. Here, we report the structure and functional characterization of two novel selective Mps1 inhibitors, BAY 1161909 and BAY 1217389, derived from structurally distinct chemical classes. BAY 1161909 and BAY 1217389 inhibited Mps1 kinase activity with IC50 values below 10 nmol/L while showing an excellent selectivity profile. In cellular mechanistic assays, both Mps1 inhibitors abrogated nocodazole-induced SAC activity and induced premature exit from mitosis ("mitotic breakthrough"), resulting in multinuclearity and tumor cell death. Both compounds efficiently inhibited tumor cell proliferation in vitro (IC50 nmol/L range). In vivo, BAY 1161909 and BAY 1217389 achieved moderate efficacy in monotherapy in tumor xenograft studies. However, in line with its unique mode of action, when combined with paclitaxel, low doses of Mps1 inhibitor reduced paclitaxel-induced mitotic arrest by the weakening of SAC activity. As a result, combination therapy strongly improved efficacy over paclitaxel or Mps1 inhibitor monotreatment at the respective MTDs in a broad range of xenograft models, including those showing acquired or intrinsic paclitaxel resistance. Both Mps1 inhibitors showed good tolerability without adding toxicity to paclitaxel monotherapy. These preclinical findings validate the innovative concept of SAC abrogation for cancer therapy and justify clinical proof-of-concept studies evaluating the Mps1 inhibitors BAY 1161909 and BAY 1217389 in combination with antimitotic cancer drugs to enhance their efficacy and potentially overcome resistance. Mol Cancer Ther; 15(4); 583-92. ©2016 AACR.

Abstract 1129: How to develop ACC1 inhibitors targeting lipid metabolism and oncogenic signaling pathways effectively and safely

Although targeting lipogenesis for cancer treatment appears to have a strong rationale, drug discovery in this field has not been fully explored due to the lack of understanding the mode of action as well as the therapeutic window. We reported previously on a class of novel ACC inhibitors with potent and selective activity against human ACC1, an isoform overexpressed in many cancer types. These ACC inhibitors revealed strong anti-tumor activity, including induction of tumor cell apoptosis in vitro and tumor regression in vivo in a sub-set of tumor models. To further demonstrate the therapeutic potential of ACC inhibitors, we conducted a series of studies in xenograft mice and rat to evaluate the anti-tumor efficacy of ACC inhibitors and to characterize their safety profile. We report that breast, prostate, and pancreatic cancers are among the most sensitive tumors to ACC inhibition. Interestingly, the anti-tumor kinetics correlated with reduction in palmitate levels without substantial changes in structural lipid components. In addition, a sub-type of KRAS mutation and activation of the Wnt pathway correlates with the sensitivity of tumors to ACC inhibitors. Treatment with ACC inhibitors at high doses caused an immediate decrease in food intake and followed with body weight loss. A clear correlation between the reduction of food intake and exposure of ACC inhibitor was observed. Upon withdrawing drug, the effect on food intake is restored. Therefore, we investigated intermittent dosing schedules and food effects on the tolerability and anti-tumor efficacy of ACC inhibitors. We could demonstrate that the tolerability was improved without compromising the efficacy compared to continuous treatment. Furthermore, feeding animals a high fat diet prevented body weight loss and meanwhile maintained the antitumor activity. These results indicate that strong reduction of food intake seems the cause of intolerability, which can be prevented and reversed either by intermittent dosing, or by exogenously supplementing with a high fat diet. Furthermore, for the first time we provided in vivo evidence that exogenous lipids could complement de novo lipogenesis inhibition in normal cells, while tumor growth requires lipogenesis irrespective of existing circulating lipids. In summary, these assessments provide scientific insights and strategy on how to best target tumor lipid metabolism and lipid signaling effectively and safely for cancer therapy.

Citation Format: Ningshu Liu, Wilhelm Bone, Sendhil S. Velan, Krishnarao Doddapuneni, Jadegoud Yaligar, Kai Thede Thede, Ursula Moenning, Xiaohe Shi, Xianfeng Tian, Elissaveta Petrova1, Franz von Nussbaum, Dominik Mumberg, Michael Brands, Karl Ziegelbauer. How to develop ACC1 inhibitors targeting lipid metabolism and oncogenic signaling pathways effectively and safely. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1129. doi:10.1158/1538-7445.AM2015-1129

Abstract DDT02-02: BAY 1143572: A first-in-class, highly selective, potent and orally available inhibitor of PTEFb/CDK9 currently in Phase I, inhibits MYC and shows convincing anti-tumor activity in multiple xenograft models by the induction of apoptosis

PTEFb/CDK9 mediated transcription of short-lived anti-apoptotic survival proteins like MYC, a key oncogene in multiple tumors, plays a critical role in cancer cell growth and survival. In addition, these survival proteins exhibit important functions in the development of resistance to chemotherapy.

In contrast to pan-CDK inhibitors which are currently evaluated in Phase I and II clinical trials, to our knowledge PTEFb selective inhibitors have not been explored for clinical utility. We report for the first time the preclinical profile and structure of BAY 1143572, a novel selective PTEFb/CDK9 inhibitor currently being investigated in a Phase I clinical trial.

BAY 1143572 had potent and highly selective PTEFb-kinase inhibitory activity in the low nanomolar range against PTEFb/CDK9 and an at least 50-fold selectivity against other CDKs in enzymatic assays. Furthermore, BAY 1143572 showed a favorable selectivity against a panel of non-CDK kinases in vitro. The potent enzymatic activity on PTEFb translated into broad antiproliferative activity against a panel of tumor cell lines with sub-micromolar IC-50 values. In line with the proposed mode of action, a concentration-dependent inhibition of the phosphorylation of the RNA polymerase II and downstream reduction of MYC mRNA and protein levels was observed in vitro. This inhibition was accompanied by an induction of apoptosis in cellular assays.

BAY 1143572 also showed single agent in vivo efficacy at tolerated doses in various xenograft tumor models in mice and rats upon once daily oral administration. Potent anti-tumor activity characterized with partial or even complete remissions could be documented in models showing different MYC gene alterations like amplifications and translocations. Treatment with BAY 1143572 resulted in a transient inhibition of intratumoral MYC mRNA and protein levels and an induction of apoptosis in these models. The inhibition of MYC mRNA was also observed in blood cells of BAY 1143572-treated rats indicating the potential clinical utility of MYC in blood cells as a pharmacodynamic marker in clinical development. The in vivo efficacy of BAY 1143572 was significantly enhanced in combination with several chemotherapeutics in different solid tumor models. These pharmacology data provided the rationale for the initiation of clinical development of BAY 1143572 in advanced cancer patients (NCT01938638).

In conclusion, our data provide preclinical proof of concept for BAY 1143572 as a potent and highly selective inhibitor of PTEFb/CDK9 with first-in-class potential. Further clinical evaluation of BAY 1143572 for the treatment of cancers dependent on the transcription of the key oncogene MYC and other short-lived survival proteins is warranted.

Citation Format: Arne Scholz, Ulrich Luecking, Gerhard Siemeister, Philip Lienau, Ulf Boemer, Peter Ellinghaus, Annette O. Walter, Ray Valencia, Stuart Ince, Franz von Nussbaum, Dominik Mumberg, Michael Brands, Karl Ziegelbauer. BAY 1143572: A first-in-class, highly selective, potent and orally available inhibitor of PTEFb/CDK9 currently in Phase I, inhibits MYC and shows convincing anti-tumor activity in multiple xenograft models by the induction of apoptosis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr DDT02-02. doi:10.1158/1538-7445.AM2015-DDT02-02

Abstract 1442: Effects of selective and broad glucose transporter (GLUT) inhibition on glucose distribution in tumor bearing mice

Malignant cells are known for their accelerated metabolism, high energy requirements, and increased glucose uptake. Transport of glucose across the plasma membrane is the first and rate-limiting step for glucose metabolism and is mediated by facilitative glucose transporter (GLUT) proteins. Increased glucose uptake in malignant cells has been associated with upregulated expression of glucose transporters, mainly overexpression of GLUT1 and/or GLUT3. There is limited knowledge about how selective (e.g. GLUT1) versus broad (multi-) GLUT inhibition affects glucose homeostasis in tumor bearing mice. Using potent small molecule inhibitors, we compared [14C]-2-Deoxy-D-Glucose (2-DG) distribution after selective GLUT1 versus GLUT1, 3 and 4 [multi-GLUT] inhibition and versus control in human NSCLC NCI-H460 tumor bearing mice. A single dose of a GLUT1 selective and a multi-GLUT inhibitor were administered to NCI-H460 tumor bearing NMRI nu/nu mice. At the respective Cmax concentrations, a bolus of 2-DG was rapidly injected intra-peritoneally and the distribution of metabolically stable 2-DG was obtained using whole-body autoradiography after 15 min and 120 min. With the multi-GLUT inhibitor only a very short inhibition of 2-DG uptake was observed in the NCI-H460 tumors while a long-lasting inhibition was detected in heart, brain and brown fat tissue. In contrast, a long-lasting inhibition of 2-DG uptake was observed in NCI-H460 tumors for the selective GLUT1 inhibitor. 2-DG concentrations were reduced in the brain following administration of the selective GLUT1 inhibitor at 15 min and returned to normal levels at 120 min while the tumor 2-DG concentration stayed low. The 2-DG findings go in parallel with the histopathological findings present in the brain and heart after treatment with the multi-GLUT inhibitor. However, similar histopathological findings have not been observed in the brain and heart after treatment with the selective GLUT-1 inhibitor.

Therefore, selective GLUT1 inhibition is associated with a sustained low 2-DG concentration in the NCI-H460 tumors while only minor changes in glucose homeostasis were observed in other organ systems.

Citation Format: Melanie Heroult, Wolfram Steinke, Anna-Lena Frisk, Sandra Borkowski, Kirstin Meyer, Heike Petrul, Iring Heisler, Maria Quanz, Roland Neuhaus, Bernd Buchmann, Thomas Mueller, Marcus Bauser, Andrea Haegebarth, Michael Brands, Karl Ziegelbauer. Effects of selective and broad glucose transporter (GLUT) inhibition on glucose distribution in tumor bearing mice. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1442. doi:10.1158/1538-7445.AM2014-1442

Abstract 4538: BAY 1112054, a highly selective, potent and orally available inhibitor of PTEFb/CDK9, shows convincing anti-tumor activity

The family of cyclin-dependent kinase (CDK) proteins consists of multiple cell cycle regulating CDK members as well as members involved in the regulation of gene transcription like CDK9/PTEFb (positive transcription elongation factor b). Inhibition of PTEFb and its direct downstream target RNA polymerase II is thought to cause rapid depletion of short-lived mRNA transcripts of important survival proteins like c-myc and Mcl-1 and thereby to induce growth delay and apoptosis in addicted tumor cells.

In contrast to pan-CDK inhibitiors which are currently evaluated in Phase I and II clinical trials, PTEFb selective inhibitors have not been explored for clinical utility.

BAY 1112054 is a potent and highly selective PTEFb-kinase inhibitor with low nanomolar activity against PTEFb/CDK9 and an at least 50-fold selectivity against other CDKs in enzymatic assays. Furthermore, BAY 1112054 shows a favourable selectivity against non-CDK kinases in vitro. The compound exhibits broad anti-proliferative activity against a panel of tumor cell lines with sub-micromolar IC-50 values.

In line with the proposed mode of action, a concentration-dependent inhibition of the phosphorylation of the RNA polymerase II was observed in A549 tumor cells. This inhibition was accompanied by a reduction of intracellular Mcl-1 protein levels. Furthermore, BAY 1112054 increased DNA fragmentation in synchronized HeLa cells upon compound treatment for 24 hours.

BAY 1112054 showed convincing in vivo efficacy at tolerated doses in two xenograft models in mice. Once daily oral treatment led to complete tumor stasis in established MOLM-13 AML xenografts. Pharmacokinetic analysis revealed that unbound plasma levels were 8 to 12 hours above the cellular IC50 in this model. In vivo efficacy and tolerability of the once daily po schedule of BAY 1112054 was confirmed in NCI-H82 SCLC xenografts. Xenografted tumors of this model showed lower levels of RNA polymerase II phosphorylation and Mcl-1 upon treatment with BAY 1112054.

In conclusion, our data provides in vitro and in vivo proof of concept for BAY 1112054, a potent and highly selective inhibitor of PTEFb/CDK9 with first-in-class potential, and warrant further clinical evaluation of PTEFb selective inhibitors for the treatment of cancers addicted to the transcription of short-lived anti-apoptotic survival proteins.

Citation Format: Arne Scholz, Ulrich Lücking, Gerhard Siemeister, Philip Lienau, Knut Eis, Antje Wengner, Kirstin Petersen, Ulf Bömer, Peter Nussbaumer, Axel Choidas, Gerd Rühter, Jan Eickhoff, Carsten Schultz-Fademrecht, Bert Klebl, Stuart Ince, Franz von Nussbaum, Dominik Mumberg, Michael Brands, Karl Ziegelbauer. BAY 1112054, a highly selective, potent and orally available inhibitor of PTEFb/CDK9, shows convincing anti-tumor activity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4538. doi:10.1158/1538-7445.AM2014-4538

Abstract 4617: BAY-ACC001, a novel ACC inhibitor, regulates fatty acids synthesis and lipid survival signaling with promising in vitro and in vivo activities in multiple preclinical tumor models

Unlike normal cells, tumors undergo intensified de novo biogenesis of fatty acids (FAs) irrespective of the available circulating lipids. Acetyl-CoA carboxylase 1 (ACC) controls the rate limiting step in FA synthesis. ACC1 is up-regulated in a variety of human tumors and strongly associated with poorer prognosis in some tumor indications. Although targeting lipogenesis for cancer treatment appeared having strong rationale, drug discovery in this field has not been fully explored due to the lack of powerful tools for both evaluation and understanding the mode of action. Here we report the identification and the functional characterization of a highly selective ACC inhibitor BAY-ACC001, a ketoenol derivative using various pharmacological and lipidomic approaches to address the mechanism of ACC inhibition in cancer cells and its efficacy in preclinical tumor models. BAY-ACC001 inhibits human ACC1 and ACC1 with biochemical IC50s of 278 nM and 2590 nM measured by ACC1- or ACC2- mediated generation of ADP, respectively. In a cellular mechanistic assay using MCF7 tumor cells, BAY-ACC001 potently inhibited malonyl-CoA synthesis with an IC50 of 62 nM. Profiling BAY-ACC001 in a panel of 100 tumor cell lines revealed strong anti-proliferative activity in a sub-set of tumor cell lines with IC50s at low 3-digit nanomolar. Of note, in contrast to the potent activity in tumor cell lines, e.g. apoptosis induction in MCF7 breast tumor cells, ACC inhibitor showed only weak anti-proliferative effect and could not induce apoptosis in a set of non-transformed mammary epithelial cells. To elucidate the anti-tumor MoA, the levels of lipid components (∼400 lipid molecules) in MCF7 cells were analyzed using lipidomic technology. Interestingly, ACC inhibition did not lead to a simple depletion of lipid in cells, evident from a significant increase in tumor apoptosis-related lipid signaling molecules ceramides. These results suggested a bi-direction linkage between FA synthesis and the regulation of tumor cell survival. Single administration of BAY-ACC001 orally at 10 mg/kg (the maximum tolerable dose is 30 mg/kg, BID) in mice strongly reduced malonyl CoA levels in tumors. Treatment of BAY-ACC001 as single agent was efficacious in multiple tumor models, including MCF7 (breast), PC3 (prostate), HCT116 (colon) and MDA-MB-435 (melanoma) xenograft models; partial tumor remissions observed in MCF7 model. Furthermore, combination with Tamoxifen was synergistic in the MCF7 tumor model in vitro and in vivo. In conclusion, the prevalence of the exacerbated de novo FA synthesis observed in primary and metastatic tumors, the ACC-mediated novel survival signal transduction discovered in this study, and robust in vitro and in vivo anti-tumor activity of BAY-ACC001 provide a strong rationale for developing novel therapeutics targeting ACC for cancer treatment.

Citation Format: Ningshu Liu, Maher Najar, Arne Scholz, Knut Eis, Ulf Bömer, Philip Lienau, Kai Thede, Dominik Mumberg, Michael Brands, Karl Ziegelbauer. BAY-ACC001, a novel ACC inhibitor, regulates fatty acids synthesis and lipid survival signaling with promising in vitro and in vivo activities in multiple preclinical tumor models. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4617. doi:10.1158/1538-7445.AM2013-4617

No difference in glycosphingolipid metabolism and mitochondrial function in glucocorticoid-induced insulin resistance in healthy men

OBJECTIVE

Glucocorticoids (GCs) are well known to induce insulin resistance; however, mechanisms that cause the impairement of the insulin signaling pathway have not yet been identified. In this study we measured whether GC-induced insulin resistance in humans is related to changes in muscle ceramide, GM3, and muscle mitochondrial function.

METHODS

In a randomized, placebo-controlled, double-blind, dose-response intervention study, 32 healthy males (aged 22 ± 3 years; body mass index 22.4 ± 1.7 kg/m(-2)) were allocated to prednisolone (PRED) 7.5 mg once daily (n = 12), PRED 30 mg once daily (n = 12), or placebo (n = 8) for 2 weeks using block randomization. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp before and after treatment. Muscle biopsies were performed to measure ceramide, monosialodihexosylganglioside (GM3), and mitochondrial function.

RESULTS

Peripheral insulin sensitivity was dose dependently decreased after the PRED treatment. Muscle ceramide and GM3 concentration and mitochondrial function were not altered by 2 weeks of PRED treatment.

CONCLUSION

Short-term GC treatment dose dependently impaired whole-body insulin sensitivity in healthy males, without concomitant changes in muscle ceramide, GM3, or mitochondrial function. These findings suggest that other mechanisms play a role in GC-related impairment of insulin sensitivity.

Angiopoietin-like protein 4 is differentially regulated by glucocorticoids and insulin in vitro and in vivo in healthy humans

OBJECTIVE

Angiopoietin-like protein 4 (Angptl4) is a circulating inhibitor of plasma triglyceride clearance via inhibition of lipoprotein lipase. The aim of the present study was to examine the regulation of Angptl4 by glucocorticoids and insulin in vivo in humans, since these factors regulate Angptl4 expression in vitro.

RESEARCH DESIGN AND METHODS

In a randomized, placebo-controlled, double-blind, dose-response intervention study, 32 healthy males (age: 22 ± 3 years; BMI 22.4 ± 1.7 kg m⁻²) were allocated to prednisolone 30 mg once daily (n = 12), prednisolone 7.5 mg once daily (n = 12), or placebo (n = 8) for 2 weeks. Angptl4 levels and lipid metabolism were measured before and at 2 weeks of treatment, in the fasted state and during a 2-step hyperinsulinemic clamp. Additionally, human hepatoma cells were treated with dexamethasone and/or insulin.

RESULTS

Compared to placebo, prednisolone treatment tended to lower fasting Angptl4 levels (P = 0.073), raised fasting insulin levels (P = 0.0004) and decreased fasting nonesterified fatty acid concentrations (NEFA) (P = 0.017). Insulin infusion reduced Angptl4 levels by 6 % (plasma insulin ~200 pmol/l, P = 0.006) and 22 % (plasma insulin ~600 pmol/l, P < 0.0001), which was attenuated by prednisolone treatment (P = 0.03). Prednisolone 7.5 mg and 30 mg dose-dependently decreased insulin-mediated suppression of lipolysis (by 11 ± 5 % and 34 ± 6 % respectively). Prednisolone 30 mg enhanced fasting triglyceride levels ( P = 0.028). Plasma Angptl4 was not related to prednisolone-induced changes in lipid metabolism. In human hepatoma cells, dexamethasone increased Angptl4 mRNA expression and protein secretion, whereas insulin had the opposite effect.

CONCLUSIONS

Insulin lowers plasma Angptl4 levels in humans by lowering NEFA and by inhibiting Angptl4 expression and release. Glucocorticoids counteract insulin-mediated suppression of Angptl4.

Abstract 3751: In vitro and in vivo pharmacological profile of BAY 1001931, a novel highly potent allosteric AKT1/2 inhibitor

The PI3K/AKT/mTOR pathway is essential for tumor growth, proliferation, survival, invasion and metastasis. AKT, a central switch in this pathway, is deregulated in a broad range of refractory and primary tumors. Importantly, activation of AKT is one of the major mechanisms by which tumors escape from and become resistant to chemo-, radio- and targeted therapies. We report on preclinical studies of BAY 1001931, a highly selective and potent allosteric AKT1/2 inhibitor. In biochemical assays, BAY 1001931 inhibits AKT1 and AKT2 with similar potency (IC50 = 16 nM) while it displays weak activity against AKT3 (IC50 ∼ 1 µM) and is inactive against ∼230 other protein/ lipid kinases. Mechanistically, BAY 1001931 blocks AKT signalling by inhibiting the phosphorylation of AKT at both Thr308 and Ser473 (IC50 = 3.3 / 5.5 nM) as well as downstream phosphorylation of 4E-BP1 (IC50 = 70 nM). The strong inhibition of cellular p-AKT translates to a selective inhibition of tumor cell proliferation in vitro. Cell lines carrying defects in the tumor suppressor PTEN or oncogenic mutations in PIK3CA are most sensitive to BAY 1001931 treatment. Moreover, characterization of BAY 1001931 in a broader breast and prostate cancer cell line panel indicated strongest anti-proliferative efficacy in luminal and HER2 positive breast cancer cell lines and in androgen sensitive prostate cancer cell lines. In vitro combination profiling showed synergistic anti-proliferative effects with anti-hormonal therapeutics in breast and prostate cancer cell lines. When dosed orally in human xenograft tumor models, BAY 1001931 induced strong pharmacodynamic inhibition of AKT phosphorylation that correlated with drug exposure. BAY 1001931 was highly efficacious in multiple xenograft tumor models of different histological types with PIK3CA mutations or PTEN deletions. In tumor models predicted to be dependent on activated AKT signalling such as the KPL4 breast tumor model (PIK3CA H1047R and HER2 overexpression), daily oral treatment with BAY 1001931 induced tumor stasis or regression at well tolerated doses. Most importantly, when combined with anti-hormonal therapies such as tamoxifen in PIK3CA breast cancer xenograft models or bicalutamide or abiraterone acetate in PTEN deleted prostate cancer xenograft models, enhanced anti-tumor efficacy with durable tumor regressions were observed. In conclusion, BAY 1001931 is a highly selective, potent allosteric AKT1/2 inhibitor with strong in vitro and in vivo activity in tumor models with activated AKT signalling and strong synergistic activity in combination with anti-hormonals in breast and prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3751. doi:1538-7445.AM2012-3751

Abstract 2799: BAY 1082439, a highly selective and balanced PI3Kα/β inhibitor demonstrated potent activity in tumors with activated PI3Kα and loss-of-function of PTEN

The PI3K pathway plays critical roles in cancer cell growth and survival, as well as in intrinsic and acquired resistance to both chemotherapy and targeted agents. These essential roles have led to the clinical development of PI3K pathway inhibitors. Due to the complexity derived from the existence of various PI3K isoforms (≥,α,α,α), and their differential roles in signal transduction, as well as cancer pathology, development of PI3K inhibitors with differential pharmacological profiles would allow exploration in different indications, combinations and dosing regimens. Having identified BAY 80-6946, an intravenously dosed, highly potent and selective PI3K inhibitor which is particularly effective in PIK3CAmut and/or Her2+ tumors, we sought to develop a novel oral PI3K inhibitor particularly effective in PTEN-loss tumors with coexisting mutation or amplification of PIK3CA and/or activation of PI3Kα (e.g., through RTKs). Herein we report the pharmacological profile of a highly selective PI3Kα/α-balanced inhibitor, BAY 1082439. BAY 1082439 has an IC50 ratio of 1:3 in biochemical assays of PI3Kα (4.9 nM) vs. PI3Kα (15.0 nM), and &gt;1000-fold selectivity against mTOR kinase. The balanced PI3Kα and PI3Kα activity of BAY 1082439 is also reflected in cellular mechanistic (p-AKT473) and proliferation assays in PI3Kα- (KPL4, BT474) vs. PI3Kα-driven (PC3, LNCaP) tumor cells. In vivo, BAY 1082439 showed clear advantages over the strong PI3Kα inhibitor BAY 80-6946 in PTEN/PI3Kα-driven tumor models (e.g., PC3 and HEC-1B), when the two compounds were compared at their MTDs. Furthermore, BAY 1082439 has unique pharmacokinetic (PK) properties with very high plasma free fractions across all species tested (33-50%), large Vss, high clearance and intermediate T1/2. The relationship of PK vs. PD and the efficacy vs. dosing regimens were investigated. BAY 1082439 showed strong p-AKT inhibition at 2 and 5 hours post-treatment while p-AKT returned to levels comparable to the vehicle group at 24 hours in all 4 tumor models tested. Interestingly, with once daily dosing, BAY 1082439 could induce tumor regression in KPL4 (PIK3CAmut and HER2+), and tumor stasis in HEC-1B (PTENdel) and in HEC-1A (PIK3CAmut) tumor models, suggesting that continuous inhibition of p-AKT may not be required for anti-tumor efficacy. In addition, comparison of different dosing regimens (QD, Q2D, D1-2/W, D1-3/W, D1-4/W to QW) at MTD indicated that QD and QW dosing produced optimal anti-tumor efficacy. These results support the hypothesis that strong pathway inhibition for a certain time period, rather than maintaining constant inhibition might lead to optimal anti-tumor efficacy along with a maximal therapeutic window. In conclusion, BAY 1082439 represents a new type of PI3K inhibitor with unique pharmacological and pharmacodynamic properties to be further explored in clinical development.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2799. doi:1538-7445.AM2012-2799

Low-dose glucocorticoid treatment affects multiple aspects of intermediary metabolism in healthy humans: a randomised controlled trial

AIM/HYPOTHESIS

To assess whether low-dose glucocorticoid treatment induces adverse metabolic effects, as is evident for high glucocorticoid doses.

METHODS

In a randomised placebo-controlled double-blind (participants and the investigators who performed the studies and assessed the outcomes were blinded) dose-response intervention study, 32 healthy men (age 22 ± 3 years; BMI 22.4 ± 1.7 kg/m(2)) were allocated to prednisolone 7.5 mg once daily (n = 12), prednisolone 30 mg once daily (n = 12), or placebo (n = 8) for 2 weeks using block randomisation. Main outcome measures were glucose, lipid and protein metabolism, measured by stable isotopes, before and at 2 weeks of treatment, in the fasted state and during a two-step hyperinsulinaemic clamp conducted in the Clinical Research Unit of the Academic Medical Centre, Amsterdam, the Netherlands

RESULTS

Prednisolone, compared with placebo, dose dependently and significantly increased fasting plasma glucose levels, whereas only prednisolone 30 mg increased fasting insulin levels (29 ± 15 pmol/l). Prednisolone 7.5 mg and prednisolone 30 mg decreased the ability of insulin to suppress endogenous glucose production (by 17 ± 6% and 46 ± 7%, respectively, vs placebo). Peripheral glucose uptake was not reduced by prednisolone 7.5 mg, but was decreased by prednisolone 30 mg by 34 ± 6% (p < 0.0001). Compared with placebo, prednisolone treatment tended to decrease lipolysis in the fasted state (p = 0.062), but both prednisolone 7.5 mg and prednisolone 30 mg decreased insulin-mediated suppression of lipolysis by 11 ± 5% and 34 ± 6%, respectively. Finally, prednisolone treatment increased whole-body proteolysis during hyperinsulinaemia, which tended to be driven by prednisolone 30 mg (5 ± 2%; p = 0.06). No side effects were reported by the study participants. All participants completed the study and were analysed.

CONCLUSIONS/INTERPRETATION

Not only at high doses but also at low doses, glucocorticoid therapy impaired intermediary metabolism by interfering with the metabolic actions of insulin on liver and adipose tissue. These data indicate that even low-dose glucocorticoids may impair glucose tolerance when administered chronically.

TRIAL REGISTRATION

ISRCTN83991850.

Dietary sugars intake and cardiovascular health: a scientific statement from the American Heart Association

High intakes of dietary sugars in the setting of a worldwide pandemic of obesity and cardiovascular disease have heightened concerns about the adverse effects of excessive consumption of sugars. In 2001 to 2004, the usual intake of added sugars for Americans was 22.2 teaspoons per day (355 calories per day). Between 1970 and 2005, average annual availability of sugars/added sugars increased by 19%, which added 76 calories to Americans' average daily energy intake. Soft drinks and other sugar-sweetened beverages are the primary source of added sugars in Americans' diets. Excessive consumption of sugars has been linked with several metabolic abnormalities and adverse health conditions, as well as shortfalls of essential nutrients. Although trial data are limited, evidence from observational studies indicates that a higher intake of soft drinks is associated with greater energy intake, higher body weight, and lower intake of essential nutrients. National survey data also indicate that excessive consumption of added sugars is contributing to overconsumption of discretionary calories by Americans. On the basis of the 2005 US Dietary Guidelines, intake of added sugars greatly exceeds discretionary calorie allowances, regardless of energy needs. In view of these considerations, the American Heart Association recommends reductions in the intake of added sugars. A prudent upper limit of intake is half of the discretionary calorie allowance, which for most American women is no more than 100 calories per day and for most American men is no more than 150 calories per day from added sugars.

Platelet dense-granule secretion plays a critical role in thrombosis and subsequent vascular remodeling in atherosclerotic mice

BACKGROUND

Platelet aggregation plays a critical role in myocardial infarction and stroke; however, the role of platelet secretion in atherosclerotic vascular disease is poorly understood. Therefore, we examined the hypothesis that platelet dense-granule secretion modulates thrombosis, inflammation, and atherosclerotic vascular remodeling after injury.

METHODS AND RESULTS

Functional deletion of the Hermansky-Pudlak syndrome 3 gene (HPS3(-/-)) markedly reduces platelet dense-granule secretion. HPS3(-/-) mice have normal platelet counts, platelet morphology, and alpha-granule number, as well as maximal secretion of the alpha-granule marker P-selectin; however, their capacity to form platelet-leukocyte aggregates is significantly reduced (P<0.05). To examine the role of platelet dense-granule secretion in these processes, atherosclerosis-prone mice with combined genetic deficiency of apolipoprotein E and HPS3 (ApoE(-/-), HPS3(-/-)) were compared with congenic, atherosclerosis-prone mice with normal platelet secretion (ApoE(-/-), HPS3(+/+)). After 16 to 18 weeks on a high-fat diet, both groups of mice had similar fasting cholesterol levels and body weight. Carotid arteries of ApoE(-/-), HPS3(+/+) mice thrombosed rapidly after FeCl(3) injury, but ApoE(-/-), HPS3(-/-) mice were completely resistant to thrombotic arterial occlusion (P<0.01). Three weeks after injury, neointimal hyperplasia (from alpha-smooth muscle actin-positive cells) was significantly less (P<0.001) in arteries from ApoE(-/-), HPS3(-/-) mice. In ApoE(-/-), HPS3(-/-) mice, there were also pronounced reductions in arterial inflammation, as indicated by a 74% decrease in CD45-positive leukocytes (P<0.01) and a 73% decrease in Mac-3-positive macrophages (P<0.05).

CONCLUSIONS

In atherosclerotic mice, reduced platelet dense-granule secretion is associated with marked protection against the development of arterial thrombosis, inflammation, and neointimal hyperplasia after vascular injury.