1
|
Schulze VK, Klar U, Kosemund D, Wengner AM, Siemeister G, Stöckigt D, Neuhaus R, Lienau P, Bader B, Prechtl S, Holton SJ, Briem H, Marquardt T, Schirok H, Jautelat R, Bohlmann R, Nguyen D, Fernández-Montalván AE, Bömer U, Eberspaecher U, Brüning M, Döhr O, Raschke M, Kreft B, Mumberg D, Ziegelbauer K, Brands M, von Nussbaum F, Koppitz M. Treating Cancer by Spindle Assembly Checkpoint Abrogation: Discovery of Two Clinical Candidates, BAY 1161909 and BAY 1217389, Targeting MPS1 Kinase. J Med Chem 2020; 63:8025-8042. [PMID: 32338514 DOI: 10.1021/acs.jmedchem.9b02035] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
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.
Collapse
Affiliation(s)
- Volker K Schulze
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Ulrich Klar
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Dirk Kosemund
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Antje M Wengner
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Gerhard Siemeister
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Detlef Stöckigt
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Roland Neuhaus
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Philip Lienau
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Benjamin Bader
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Stefan Prechtl
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Simon J Holton
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Hans Briem
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Tobias Marquardt
- Research & Development, Pharmaceuticals, Bayer AG, 42113 Wuppertal, Germany
| | - Hartmut Schirok
- Research & Development, Pharmaceuticals, Bayer AG, 42113 Wuppertal, Germany
| | - Rolf Jautelat
- Research & Development, Pharmaceuticals, Bayer AG, 42113 Wuppertal, Germany
| | - Rolf Bohlmann
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Duy Nguyen
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | | | - Ulf Bömer
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Uwe Eberspaecher
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Michael Brüning
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Olaf Döhr
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Marian Raschke
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Bertolt Kreft
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Dominik Mumberg
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Karl Ziegelbauer
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Michael Brands
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Franz von Nussbaum
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| | - Marcus Koppitz
- Research & Development, Pharmaceuticals, Bayer AG, 13353 Berlin, Germany
| |
Collapse
|
2
|
Möller C, Bone W, Cleve A, Klar U, Rotgeri A, Rottmann A, Schultze‐Mosgau M, Wagenfeld A, Schwede W. Front Cover: Discovery of Vilaprisan (BAY 1002670): A Highly Potent and Selective Progesterone Receptor Modulator Optimized for Gynecologic Therapies (ChemMedChem 21/2018). ChemMedChem 2018. [DOI: 10.1002/cmdc.201800681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Wilhelm Bone
- Bayer AGPharmaceuticals R&D 13342 Berlin Germany
| | - Arwed Cleve
- Bayer AGPharmaceuticals R&D 13342 Berlin Germany
| | - Ulrich Klar
- Retired, formerly at: Bayer AGPharmaceuticals R&D 13342 Berlin Germany
| | | | | | | | | | | |
Collapse
|
3
|
Möller C, Bone W, Cleve A, Klar U, Rotgeri A, Rottmann A, Schultze‐Mosgau M, Wagenfeld A, Schwede W. Discovery of Vilaprisan (BAY 1002670): A Highly Potent and Selective Progesterone Receptor Modulator Optimized for Gynecologic Therapies. ChemMedChem 2018; 13:2271-2280. [PMID: 30407750 PMCID: PMC6282584 DOI: 10.1002/cmdc.201800487] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 12/28/2022]
Abstract
Progesterone plays an important role in the female reproductive system. However, there is also evidence that gynecologic disorders/diseases such as uterine fibroids and endometriosis are progesterone-dependent. Steroidal and non-steroidal selective progesterone receptor modulators (SPRMs) have shown potential for the treatment of such diseases. Steroidal SPRMs, including mifepristone and ulipristal acetate, have proven effective in clinical trials. However, several steroidal SPRMs containing a dimethylamino substituent have been associated with elevated liver enzymes in patients. An earlier drug discovery program identified lonaprisan as a highly selective SPRM that did not show drug-related change in liver enzyme activity. Building on data obtained from that work, here we describe the research program that culminated in the discovery of a novel steroidal SPRM, vilaprisan, which combines an extremely high potency with very favorable drug metabolism and pharmacokinetic properties. Vilaprisan has entered clinical development and is currently undergoing phase 3 clinical trials.
Collapse
Affiliation(s)
| | | | - Arwed Cleve
- Bayer AGPharmaceuticals R&D13342BerlinGermany
| | - Ulrich Klar
- Retired, formerly at: Bayer AGPharmaceuticals R&D13342BerlinGermany
| | | | | | | | | | | |
Collapse
|
4
|
Wengner AM, Siemeister G, Koppitz M, Schulze V, Kosemund D, Klar U, Stoeckigt D, Neuhaus R, Lienau P, Bader B, Prechtl S, Raschke M, Frisk AL, von Ahsen O, Michels M, Kreft B, von Nussbaum F, Brands M, Mumberg D, Ziegelbauer K. Novel Mps1 Kinase Inhibitors with Potent Antitumor Activity. Mol Cancer Ther 2016; 15:583-92. [PMID: 26832791 DOI: 10.1158/1535-7163.mct-15-0500] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 01/04/2016] [Indexed: 11/16/2022]
Abstract
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.
Collapse
Affiliation(s)
| | | | | | | | | | - Ulrich Klar
- Bayer Pharma AG, Drug Discovery, Berlin, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Wengner AM, Siemeister G, Koppitz M, Schulze V, Kosemund D, Klar U, Stoeckigt D, Neuhaus R, Lienau P, Bader B, Prechtl S, Doehr O, Raschke M, von Ahsen O, Elbi C, Bruns I, Michels M, Kreft B, von Nussbaum F, Brands M, Mumberg D, Ziegelbauer K. Abstract 3090: Novel Mps1 kinase inhibitors with potent anti-tumor activity. Mol Cell Biol 2015. [DOI: 10.1158/1538-7445.am2015-3090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
6
|
Gottfried K, Klar U, Platzek J, Zorn L. Biocatalysis at Work: Applications in the Development of Sagopilone. ChemMedChem 2015; 10:1240-8. [DOI: 10.1002/cmdc.201500138] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Indexed: 01/24/2023]
|
7
|
Affiliation(s)
- Ulrich Klar
- Bayer Healthcare, Global Drug Discovery - Medicinal Chemistry
| | - Johannes Platzek
- Bayer Healthcare, Global Drug Discovery - Global Chemical Development, Process R&D
| |
Collapse
|
8
|
Eschenbrenner J, Winsel S, Hammer S, Sommer A, Mittelstaedt K, Drosch M, Klar U, Sachse C, Hannus M, Seidel M, Weiss B, Merz C, Siemeister G, Hoffmann J. Evaluation of activity and combination strategies with the microtubule-targeting drug sagopilone in breast cancer cell lines. Front Oncol 2011; 1:44. [PMID: 22649765 PMCID: PMC3355879 DOI: 10.3389/fonc.2011.00044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 10/31/2011] [Indexed: 12/14/2022] Open
Abstract
Sagopilone, a fully synthetic epothilone, is a microtubule-stabilizing agent optimized for high in vitro and in vivo activity against a broad range of tumor models, including those resistant to paclitaxel and other systemic treatments. Sagopilone development is accompanied by translational research studies to evaluate the molecular mode of action, to recognize mechanisms leading to resistance, to identify predictive response biomarkers, and to establish a rationale for combination with different therapies. Here, we profiled sagopilone activity in breast cancer cell lines. To analyze the mechanisms of mitotic arrest and apoptosis and to identify additional targets and biomarkers, an siRNA-based RNAi drug modifier screen interrogating 300 genes was performed in four cancer cell lines. Defects of the spindle assembly checkpoint (SAC) were identified to cause resistance against sagopilone-induced mitotic arrest and apoptosis. Potential biomarkers for resistance could therefore be functional defects like polymorphisms or mutations in the SAC, particularly in the central SAC kinase BUB1B. Moreover, chromosomal heterogeneity and polyploidy are also potential biomarkers of sagopilone resistance since they imply an increased tolerance for aberrant mitosis. RNAi screening further demonstrated that the sagopilone-induced mitotic arrest can be enhanced by concomitant inhibition of mitotic kinesins, thus suggesting a potential combination therapy of sagopilone with a KIF2C (MCAK) kinesin inhibitor. However, the combination of sagopilone and inhibition of the prophase kinesin KIF11 (EG5) is antagonistic, indicating that the kinesin inhibitor has to be highly specific to bring about the required therapeutic benefit.
Collapse
Affiliation(s)
- Julia Eschenbrenner
- Global Drug Discovery, Therapeutic Research Group Oncology, Bayer Healthcare Pharmaceuticals Berlin, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Strube A, Suominen MI, Rissanen JP, Mumberg D, Klar U, Halleen JM, Käkönen SM. The anti-tumor agent sagopilone shows antiresorptive effects both in vitro and in vivo. Osteoporos Int 2011; 22:2887-93. [PMID: 21104229 DOI: 10.1007/s00198-010-1486-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Accepted: 11/04/2010] [Indexed: 11/24/2022]
Abstract
UNLABELLED Sagopilone, a fully synthetic epothilone and very potent anti-tumor agent, has proved to be efficient in inhibiting bone destruction and tumor burden in a mouse model of breast cancer bone metastasis. In addition to its antiproliferative effects, this study shows direct effects of sagopilone on bone resorption and osteoclast activity. INTRODUCTION Sagopilone, a novel fully synthetic third-generation epothilone, has proved to be efficient in inhibiting bone destruction and tumor burden in a mouse model of breast cancer bone metastasis. The aim of this study was to investigate whether the effect was primarily due to sagopilone's antiproliferative effect and consequent inhibition of tumor cell growth, or if sagopilone exerts direct effects on bone resorption and osteoclast activity. METHODS Sagopilone was studied and compared to paclitaxel in vitro in human osteoclast differentiation and activity cultures. For studying the potential of sagopilone for inhibiting bone resorption in vivo, a mouse model of ovariectomy (ovx)-induced osteoporosis was utilized. RESULTS Sagopilone inhibited osteoclast differentiation and activity more efficiently than paclitaxel and showed less cytotoxicity. Whereas sagopilone showed inhibitory effects on human osteoclast differentiation and activity already at 5 and 15 nM, respectively, paclitaxel started to show effects only at 20 and 100 nM concentrations, respectively. Sagopilone treatment increased BMD In the mouse ovx model even though a non-optimized dose was used which is effective in tumor-bearing mice. CONCLUSION This is the first study to evaluate sagopilone's effects on bone resorption in non-cancerous situation. The evidence that sagopilone is beneficial for bone will strengthen the status of sagopilone as an anti-cancer compound compared to other microtubule stabilizing agents.
Collapse
Affiliation(s)
- A Strube
- Global Drug Discovery, Bayer Schering Pharma AG, Berlin, Germany
| | | | | | | | | | | | | |
Collapse
|
10
|
Winsel S, Sommer A, Eschenbrenner J, Mittelstaedt K, Klar U, Hammer S, Hoffmann J. Molecular mode of action and role of TP53 in the sensitivity to the novel epothilone sagopilone (ZK-EPO) in A549 non-small cell lung cancer cells. PLoS One 2011; 6:e19273. [PMID: 21559393 PMCID: PMC3084814 DOI: 10.1371/journal.pone.0019273] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 03/31/2011] [Indexed: 01/01/2023] Open
Abstract
Sagopilone, an optimized fully synthetic epothilone, is a microtubule-stabilizing
compound that has shown high in vitro and in
vivo activity against a broad range of human tumor models. We
analyzed the differential mechanism of action of sagopilone in non-small cell
lung cancer cell lines in vitro. Sagopilone inhibited
proliferation of non-small cell lung cancer cell lines at lower nanomolar
concentration. The treatment with sagopilone caused strong disturbances of
cellular cytoskeletal organization. Two concentration-dependent phenotypes were
observed. At 2.5 nM sagopilone or 4 nM paclitaxel an aneuploid phenotype occur
whereas a mitotic arrest phenotype was induced by 40 nM sagopilone or
paclitaxel. Interestingly, treatment with 2.5 nM of sagopilone effectively
inhibited cell proliferation, but - compared to high concentrations (40 nM) -
only marginally induced apoptosis. Treatment with a high versus a low
concentration of sagopilone or paclitaxel regulates a non-overlapping set of
genes, indicating that both phenotypes substantially differ from each other.
Genes involved in G2/M phase transition and the spindle assembly checkpoint,
like Cyclin B1 and BUBR1 were upregulated by treatment with 40 nM sagopilone.
Unexpectedly, also genes involved in DNA damage response were upregulated under
that treatment. In contrast, treatment of A549 cells with a low concentration of
sagopilone revealed an upregulation of direct transcriptional target genes of
TP53, like CDKN1A, MDM2, GADD45A, FAS. Knockdown of TP53, which inhibited the
transcriptional induction of TP53 target genes, led to a significant increase in
apoptosis induction in A549 cells when treated with a low concentration of
sagopilone. The results indicate that activation of TP53 and its downstream
effectors like CDKN1A by low concentrations of sagopilone is responsible for the
relative apoptosis resistance of A549 cells and might represent a mechanism of
resistance to sagopilone.
Collapse
Affiliation(s)
- Sebastian Winsel
- Global Drug Discovery, Bayer Healthcare,
Berlin, Germany
- Institute for Chemistry-Biochemistry, Freie
Universität Berlin, Berlin, Germany
- Medical Biotechnology, VTT Technical Research
Centre of Finland, Turku, Finland
| | - Anette Sommer
- Global Drug Discovery, Bayer Healthcare,
Berlin, Germany
| | - Julia Eschenbrenner
- Global Drug Discovery, Bayer Healthcare,
Berlin, Germany
- Institut für Biotechnologie, Technische
Universität Berlin, Berlin, Germany
| | - Kevin Mittelstaedt
- Global Drug Discovery, Bayer Healthcare,
Berlin, Germany
- Department of Medicine, The University of
Melbourne, Melbourne, Australia
| | - Ulrich Klar
- Global Drug Discovery, Bayer Healthcare,
Berlin, Germany
| | - Stefanie Hammer
- Global Drug Discovery, Bayer Healthcare,
Berlin, Germany
- * E-mail: (SH); (JH)
| | - Jens Hoffmann
- Global Drug Discovery, Bayer Healthcare,
Berlin, Germany
- Experimental Pharmacology,
Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
- * E-mail: (SH); (JH)
| |
Collapse
|
11
|
|
12
|
Hammer S, Sommer A, Fichtner I, Becker M, Rolff J, Merk J, Klar U, Hoffmann J. Comparative profiling of the novel epothilone, sagopilone, in xenografts derived from primary non-small cell lung cancer. Clin Cancer Res 2010; 16:1452-65. [PMID: 20179216 DOI: 10.1158/1078-0432.ccr-09-2455] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Characterization of new anticancer drugs in a few xenograft models derived from established human cancer cell lines frequently results in the discrepancy between preclinical and clinical results. To take the heterogeneity of tumors into consideration more thoroughly, we describe here a preclinical approach that may allow a more rational clinical development of new anticancer drugs. EXPERIMENTAL DESIGN We tested Sagopilone, an optimized fully synthetic epothilone, in 22 well-characterized patient-derived non-small cell lung cancer models and correlated results with mutational and genome-wide gene expression analysis. RESULTS Response analysis according to clinical trial criteria revealed that Sagopilone induced overall responses in 64% of the xenograft models (14 of 22), with 3 models showing stable disease and 11 models showing partial response. A comparison with response rates for established drugs showed the strong efficacy of Sagopilone in non-small cell lung cancer. In gene expression analyses, Sagopilone induced tubulin isoforms in all tumor samples, but genes related to mitotic arrest only in responder models. Moreover, tumors with high expression of genes involved in cell adhesion/angiogenesis as well as of wild-type TP53 were more likely to be resistant to Sagopilone therapy. As suggested by these findings, Sagopilone was combined with Bevacizumab and Sorafenib, drugs targeting vascular endothelial growth factor signaling, in Sagopilone-resistant models and, indeed, antitumor activity could be restored. CONCLUSION Analyses provided here show how preclinical studies can provide hypotheses for the identification of patients who more likely will benefit from new drugs as well as a rationale for combination therapies to be tested in clinical trials.
Collapse
Affiliation(s)
- Stefanie Hammer
- Bayer Schering Pharma AG, Global Drug Discovery, Berlin, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Strube A, Hoffmann J, Stepina E, Hauff P, Klar U, Käkönen SM. Sagopilone inhibits breast cancer bone metastasis and bone destruction due to simultaneous inhibition of both tumor growth and bone resorption. Clin Cancer Res 2009; 15:3751-9. [PMID: 19470728 DOI: 10.1158/1078-0432.ccr-08-3123] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Bone metastases have a considerable impact on quality of life in patients with breast and other cancers. Tumors produce osteoclast-activating factors, whereas bone resorption promotes the growth of tumor cells, thus leading to a "vicious cycle" of bone metastasis. Sagopilone, a novel, fully synthetic epothilone, inhibits the growth of breast cancer cells in vitro and in vivo, and here we report its activity in the MDA-MB-231(SA) breast cancer bone metastasis mouse model. EXPERIMENTAL DESIGN The potency of sagopilone was determined in treatment models simulating the adjuvant (preventive) and metastatic (therapeutic) settings in the clinic. RESULTS We showed that sagopilone inhibited tumor burden and bone destruction, in addition to reducing tumor-induced cachexia and paraplegia. The reduction in osteolytic lesions, tumor growth in bone, and weight loss was statistically significant in the preventive model compared with the vehicle group. In the therapeutic model, sagopilone treatment significantly lowered the number of activated osteoclasts and significantly reduced the osteolytic lesion area, bone volume loss, and bone resorption compared with vehicle treatment while simultaneously inhibiting tumor burden. An in vitro assay confirmed that sagopilone inhibited osteoclast activation without cytotoxic effects, whereas paclitaxel resulted in lower inhibition and high levels of cytotoxicity. CONCLUSIONS Sagopilone seems to inhibit the vicious cycle at both the tumor growth and bone resorption stages, suggesting the possibility for substantial benefit in the treatment of patients with breast cancer at risk from bone metastases or with bone lesions already present. Phase II clinical trials with sagopilone in patients with breast cancer are ongoing.
Collapse
Affiliation(s)
- Anne Strube
- Global Drug Discovery, Bayer Schering Pharma AG, Free University Berlin, Berlin, Germany
| | | | | | | | | | | |
Collapse
|
14
|
Höhne A, Yu L, Mu L, Reiher M, Voigtmann U, Klar U, Graham K, Schubiger P, Ametamey S. Organofluorosilanes as Model Compounds for18F-Labeled Silicon-Based PET Tracers and their Hydrolytic Stability: Experimental Data and Theoretical Calculations (PET=Positron Emission Tomography). Chemistry 2009; 15:3736-43. [DOI: 10.1002/chem.200802437] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
15
|
Klar U, Hoffmann J, Giurescu M. Sagopilone (ZK-EPO): from a natural product to a fully synthetic clinical development candidate. Expert Opin Investig Drugs 2009; 17:1735-48. [PMID: 18922109 DOI: 10.1517/13543784.17.11.1735] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Tubulin is among the most established and clinically validated targets in oncology. The taxanes, paclitaxel and docetaxel, stabilize microtubules and have shown significant clinical activity, but factors such as the development of resistance can limit their clinical use. The epothilones are a novel class of natural microtubule-stabilizing products with potential activity in an expanded spectrum of tumour indications. OBJECTIVE In an extensive lead optimization programme, we selected sagopilone from 350 compounds produced by total synthesis because of its combination of potent activity and good tolerability in tumour models. It is the first fully synthetic epothilone in clinical development. METHODS Here we review the directed optimization of the natural product epothilone B to produce sagopilone, along with its mechanism of action, preclinical data and emerging clinical results. RESULTS/CONCLUSIONS We show how this optimization process translated into superior preclinical activity, coupled with a favourable tolerability profile. Activity has been determined in a number of animal models, including those from tumours resistant to other systemic treatments. The approach used to develop sagopilone may become more common as structure-driven research is increasingly employed to exploit the enormous potential of natural products, in parallel with other targeted approaches, heralding a new era of anticancer therapy.
Collapse
Affiliation(s)
- Ulrich Klar
- Bayer Schering Pharma AG, Medicinal Chemistry, Berlin, Germany.
| | | | | |
Collapse
|
16
|
Hoffmann J, Fichtner I, Lemm M, Lienau P, Hess-Stumpp H, Rotgeri A, Hofmann B, Klar U. Sagopilone crosses the blood-brain barrier in vivo to inhibit brain tumor growth and metastases. Neuro Oncol 2008; 11:158-66. [PMID: 18780814 DOI: 10.1215/15228517-2008-072] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The aim of this study was to determine the efficacy of sagopilone (ZK-EPO), a novel epothilone, compared with other anticancer agents in orthotopic models of human primary and secondary brain tumors. Autoradiography and pharmacokinetic analyses were performed on rats and mice to determine passage across the blood-brain barrier and organ distribution of sagopilone. Mice bearing intracerebral human tumors (U373 or U87 glioblastoma, MDA-MB-435 melanoma, or patient-derived non-small-cell lung cancer [NSCLC]) were treated with sagopilone 5-10 mg/kg, paclitaxel 8-12.5 mg/kg (or temozolomide, 100 mg/kg) or control (vehicle only). Tumor volume was measured to assess antitumor activity. Sagopilone crossed the blood-brain barrier in both rat and mouse models, leading to therapeutically relevant concentrations in the brain with a long half-life. Sagopilone exhibited significant antitumor activity in both the U373 and U87 models of human glioblastoma, while paclitaxel showed a limited effect in the U373 model. Sagopilone significantly inhibited the growth of tumors from CNS metastasis models (MDA-MB-435 melanoma and patient-derived Lu7187 and Lu7466 NSCLC) implanted in the brains of nude mice, in contrast to paclitaxel or temozolomide. Sagopilone has free access to the brain. Sagopilone demonstrated significant antitumor activity in orthotopic models of both glioblastoma and CNS metastases compared with paclitaxel or temozolomide, underlining the value of further research evaluating sagopilone in the treatment of brain tumors. Sagopilone is currently being investigated in a broad phase II clinical trial program, including patients with glioblastoma, NSCLC, breast cancer, and melanoma.
Collapse
Affiliation(s)
- Jens Hoffmann
- Bayer Schering Pharma AG, TRG Oncology, Berlin, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Höhne A, Mu L, Honer M, Schubiger PA, Ametamey SM, Graham K, Stellfeld T, Borkowski S, Berndorff D, Klar U, Voigtmann U, Cyr JE, Friebe M, Dinkelborg L, Srinivasan A. Synthesis, 18F-labeling, and in vitro and in vivo studies of bombesin peptides modified with silicon-based building blocks. Bioconjug Chem 2008; 19:1871-9. [PMID: 18754574 DOI: 10.1021/bc800157h] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The gastrin-releasing peptide receptor (GRPr) is overexpressed on various human tumors. The goal of our study was the synthesis of new 18F-labeled bombesin analogues for the PET imaging of GRPr expression in prostate tumor using a silicon-based one-step n. c. a. radiolabeling method. The silicon-containing building blocks were efficiently coupled to the N-terminus of the peptides via solid-phase synthesis. Radiolabeling of the obtained peptide precursors proceeded smoothly under acidic conditions (34-85% conversion). Using the di-tert-butyl silyl building block as labeling moiety, products containing a hydrolytically stable 18F-label were obtained. In in vitro receptor binding experiments 2-(4-(di-tert-butylfluorosilyl)phenyl)acetyl-Arg-Ava-Gln-Trp-Ala-Val-NMeGly-His-Sta-Leu-NH 2 ( 4b, IC50 = 22.9 nM) displayed a 12-fold higher binding affinity than 2-(4-(di-tert-butylfluorosilyl)phenyl)acetyl-Arg-Ava-Gln-Trp-Ala-Val-Gly-His(3Me)-Sta-Leu-NH2 ( 3b, IC50 = 276.6 nM), and 4b was therefore chosen for further evaluation. In vitro and ex vivo metabolite studies of [18F]4b showed no significant degradation. In biodistribution experiments, tumor uptake of [18F]4b was low and unspecific, whereas the GRPr-rich pancreas revealed a high and specific accumulation of the radiotracer. This study demonstrates the applicability of our silicon-based one-step n. c. a. radiolabeling method for the synthesis of new 18F-labeled bombesin derivatives. This innovative approach represents a general, straightforward access to radiolabeled peptides as PET imaging probes.
Collapse
Affiliation(s)
- Aileen Höhne
- Center for Radiopharmaceutical Science of ETH, PSI and USZ, Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Mu L, Höhne A, Schubiger PA, Ametamey SM, Graham K, Cyr JE, Dinkelborg L, Stellfeld T, Srinivasan A, Voigtmann U, Klar U. Silicon-based building blocks for one-step 18F-radiolabeling of peptides for PET imaging. Angew Chem Int Ed Engl 2008; 47:4922-5. [PMID: 18496798 DOI: 10.1002/anie.200705854] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Linjing Mu
- Center for Radiopharmaceutical Science of ETH, PSI and USZ, ETH-Hönggerberg, D-CHAB IPW HCI H427, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Hoffmann J, Vitale I, Buchmann B, Galluzzi L, Schwede W, Senovilla L, Skuballa W, Vivet S, Lichtner RB, Vicencio JM, Panaretakis T, Siemeister G, Lage H, Nanty L, Hammer S, Mittelstaedt K, Winsel S, Eschenbrenner J, Castedo M, Demarche C, Klar U, Kroemer G. Improved cellular pharmacokinetics and pharmacodynamics underlie the wide anticancer activity of sagopilone. Cancer Res 2008; 68:5301-8. [PMID: 18593931 DOI: 10.1158/0008-5472.can-08-0237] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Sagopilone (ZK-EPO) is the first fully synthetic epothilone undergoing clinical trials for the treatment of human tumors. Here, we investigate the cellular pathways by which sagopilone blocks tumor cell proliferation and compare the intracellular pharmacokinetics and the in vivo pharmacodynamics of sagopilone with other microtubule-stabilizing (or tubulin-polymerizing) agents. Cellular uptake and fractionation/localization studies revealed that sagopilone enters cells more efficiently, associates more tightly with the cytoskeleton, and polymerizes tubulin more potently than paclitaxel. Moreover, in contrast to paclitaxel and other epothilones [such as the natural product epothilone B (patupilone) or its partially synthetic analogue ixabepilone], sagopilone is not a substrate of the P-glycoprotein efflux pumps. Microtubule stabilization by sagopilone caused mitotic arrest, followed by transient multinucleation and activation of the mitochondrial apoptotic pathway. Profiling of the proapoptotic signal transduction pathway induced by sagopilone with a panel of small interfering RNAs revealed that sagopilone acts similarly to paclitaxel. In HCT 116 colon carcinoma cells, sagopilone-induced apoptosis was partly antagonized by the knockdown of proapoptotic members of the Bcl-2 family, including Bax, Bak, and Puma, whereas knockdown of Bcl-2, Bcl-X(L), or Chk1 sensitized cells to sagopilone-induced cell death. Related to its improved subcellular pharmacokinetics, however, sagopilone is more cytotoxic than other epothilones in a large panel of human cancer cell lines in vitro and in vivo. In particular, sagopilone is highly effective in reducing the growth of paclitaxel-resistant cancer cells. These results underline the processes behind the therapeutic efficacy of sagopilone, which is now evaluated in a broad phase II program.
Collapse
Affiliation(s)
- Jens Hoffmann
- Bayer Schering Pharma AG, TRG Oncology, Müllerstrasse 72-178, G-13342 Berlin, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Mu L, Höhne A, Schubiger P, Ametamey S, Graham K, Cyr J, Dinkelborg L, Stellfeld T, Srinivasan A, Voigtmann U, Klar U. Siliciumbausteine für eine einstufige18F-Radiomarkierung von Peptiden für die PET-Bildgebung. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200705854] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
21
|
|
22
|
Winsel S, Hammer S, Buchmann B, Schwede W, Skuballa W, Siemeister G, Klar U, Hoffmann J. SAGOPILONE, A NOVEL EPOTHILONE, INHIBITS TUMOR CELL GROWTH IN PRECLINICAL MODELS OF UROLOGICAL CANCER. J Urol 2008. [DOI: 10.1016/s0022-5347(08)61407-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
23
|
Hammer S, Arnold N, Hilpert F, Bräutigam K, Sommer A, Winsel S, Klar U, Hoffmann J. 5009 ORAL Significant antitumour activity of the novel epothilone ZK-EPO against in vitro and in vivo models of ovarian cancer. EJC Suppl 2007. [DOI: 10.1016/s1359-6349(07)71181-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
24
|
Klar U, Buchmann B, Schwede W, Skuballa W, Hoffmann J, Lichtner RB. Titelbild: Total Synthesis and Antitumor Activity of ZK-EPO: The First Fully Synthetic Epothilone in Clinical Development (Angew. Chem. 47/2006). Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200690162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
25
|
Klar U, Buchmann B, Schwede W, Skuballa W, Hoffmann J, Lichtner RB. Total Synthesis and Antitumor Activity of ZK-EPO: The First Fully Synthetic Epothilone in Clinical Development. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200602785] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
26
|
Klar U, Buchmann B, Schwede W, Skuballa W, Hoffmann J, Lichtner RB. Cover Picture: Total Synthesis and Antitumor Activity of ZK-EPO: The First Fully Synthetic Epothilone in Clinical Development (Angew. Chem. Int. Ed. 47/2006). Angew Chem Int Ed Engl 2006. [DOI: 10.1002/anie.200690162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
27
|
Klar U, Buchmann B, Schwede W, Skuballa W, Hoffmann J, Lichtner RB. Total Synthesis and Antitumor Activity of ZK-EPO: The First Fully Synthetic Epothilone in Clinical Development. Angew Chem Int Ed Engl 2006; 45:7942-8. [PMID: 17006870 DOI: 10.1002/anie.200602785] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ulrich Klar
- Schering AG, Research Center Europe, Müllerstrasse 178, 13342 Berlin, Germany.
| | | | | | | | | | | |
Collapse
|
28
|
Klar U, Deicke P, Pletsch A. An Alternative Generation of a 13.14-Carbon-Carbon Triple Bond in Prostanoids. SYNTHETIC COMMUN 2006. [DOI: 10.1080/00397919308011177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- U. Klar
- a Research Laboratories of Schering AG, Müllerstr , 170-178, W-1000, Berlin, 65, FRG
| | - P. Deicke
- a Research Laboratories of Schering AG, Müllerstr , 170-178, W-1000, Berlin, 65, FRG
| | - A. Pletsch
- a Research Laboratories of Schering AG, Müllerstr , 170-178, W-1000, Berlin, 65, FRG
| |
Collapse
|
29
|
|
30
|
Klar U, Röhr B, Kuczynski F, Schwede W, Berger M, Skuballa W, Buchmann B. Efficient Chiral Pool Synthesis of the C1-C6 Fragment of Epothilones. SYNTHESIS-STUTTGART 2005. [DOI: 10.1055/s-2004-834936] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
31
|
Hoffmann J, Lichtner R, Rotgeri A, Fichtner I, Klar U. 521 New synthetic Epothilone derivative ZKEPO inhibits the proliferation of a human glioma implanted orthotopically in nude mice. EJC Suppl 2004. [DOI: 10.1016/s1359-6349(04)80529-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
|
32
|
Lichtner RB, Rotgeri A, Bunte T, Buchmann B, Hoffmann J, Schwede W, Skuballa W, Klar U. Subcellular distribution of epothilones in human tumor cells. Proc Natl Acad Sci U S A 2001; 98:11743-8. [PMID: 11562452 PMCID: PMC58800 DOI: 10.1073/pnas.171023398] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Epothilones are a new class of natural and potent antineoplastic agents that stabilize microtubules. Although 12,13-epoxide derivatives are potent antiproliferative agents, the activities of the corresponding 12,13-olefin analogs are significantly decreased. These data were confirmed for two new analogs, 6-propyl-EpoB (pEB) and 6-propyl-EpoD (pED), in comparison with the natural compounds EpoB/EpoD, by using human A431, MCF7, and MDR1-overexpressing NCI/Adr cells. By using tritiated pEB/pED, compound uptake, release, and nuclear accumulation were investigated in A431 and NCI/Adr cells. In these cells, epothilones can principally be recognized and exported by Verapamil-sensitive efflux pumps, which are not identical to MDR1. The degree of export depends on the structure, olefin vs. epoxide-analog, and also on the intracellular drug concentration. The accumulation of pED used at 3.5 or 70 nM, respectively, was increased in the presence of 10 microM Verapamil in both cell lines 2- to 8-fold. In contrast, the intracellular levels of pEB were affected by Verapamil only at 3.5 nM pEB in NCI/Adr (2-fold) and not in A431 cells. In addition, strong nuclear accumulation was observed for pEB (40-50%) but not paclitaxel or pED (5-15%) in both cell lines. Our study suggests that differences in growth inhibitory efficacy between epoxide and olefin analogs may be based on different mechanisms of drug accumulation and subcellular distribution.
Collapse
Affiliation(s)
- R B Lichtner
- Research Laboratories of Schering AG, Müllerstrasse 178, 13342 Berlin, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Lichtner RB, Menrad A, Sommer A, Klar U, Schneider MR. Signaling-inactive epidermal growth factor receptor/ligand complexes in intact carcinoma cells by quinazoline tyrosine kinase inhibitors. Cancer Res 2001; 61:5790-5. [PMID: 11479217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Several inhibitors of EGF receptor (EGFR) tyrosine kinase activity have been developed that compete with ATP at its binding site such as the quinazolines PD 153035 and ZD 1839 or the 4,5-dianilino-phthalimides DAPH1 and DAPH2. When tested on human A431 cells, the quinazolines completely blocked EGF-induced receptor phosphorylation at 100 nM, whereas it was inhibited by DAPH1 and DAPH2 by only 20% at 3 microM. Quinazoline-treated A431 as well as tumor cells expressing less EGFR (A549, MDA MB 231, and T47D) bound 3- to 6-fold more (125)I-labeled EGF than untreated intact control cells. Scatchard analysis revealed the disappearance of low- and high-affinity EGFR on A431 cells upon PD 153035 treatment. A single receptor class of intermediate ligand binding affinity emerged and its number corresponded to the sum of the two classes. DAPH1 and DAPH2 did not change ligand binding properties of EGFR. PD 153035 exerted the most potent effects on EGF binding to A431 or on inhibiting EGF-stimulated growth of rat MTLn3 cells at low ligand concentrations. Cross-linking of EGFR on PD 153035-treated A431 cells indicated the formation of inactive dimers that further increased upon addition of EGF. Chemical cross-linking of (125)I-labeled EGF to PD 153035-treated A431 cells revealed increased binding to monomeric and dimeric EGFR. Thus, the quinazolines sequestered EGFR plus the ligand into inactive receptor/ligand complexes. This novel mode of action of quinazoline tyrosine kinase inhibitors may be the basis for their extraordinary potency especially in conditions when the ligand is present in limiting amounts.
Collapse
Affiliation(s)
- R B Lichtner
- Research Laboratories of Schering AG, 13342 Berlin, Germany.
| | | | | | | | | |
Collapse
|
34
|
Abstract
A new class of borneol esters that might be considered as biological analogs of paclitaxel regarding their action on microtubules has been found. By structure-activity optimizations, compounds stabilizing microtubules much better than paclitaxel while showing a remarkably reduced cytotoxic activity were obtained. This dissoziation will open completely new therapeutic areas.
Collapse
Affiliation(s)
- U Klar
- Research Laboratories of Schering AG, Berlin, Germany
| | | | | | | | | |
Collapse
|
35
|
|
36
|
Cleve A, Fritzemeier KH, Heinrich N, Klar U, Müller-Fahrnow A, Neef G, Ottow E, Schwede W. 11β-Aryl steroids in the androstene series. The role of the 11β-region in steroid progesterone receptor interaction. Tetrahedron 1996. [DOI: 10.1016/0040-4020(95)00983-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
37
|
Abstract
The chemistry and biology of novel TXA2(TP)-receptor agonists based on the prostanoid skeleton is described and structure-activity-relationships are discussed. One compound,(5Z,13E), (9R,15R)-9-fluoro-15-hydroxy-16-phenoxy-17,18,19,20-tetranor- 5,13-prostadienoic acid (33), was identified which is 10 times more potent than the standard TP-receptor against U 46619.
Collapse
Affiliation(s)
- K D Joachim
- Research Laboratories of Schering AG, Berlin, Germany
| | | | | | | | | |
Collapse
|
38
|
|
39
|
Deicke P, Klar U. Syntheses of new metabolically stabilized TXA2/PGH2-receptor antagonists and their biological properties. Bioorg Med Chem Lett 1992. [DOI: 10.1016/s0960-894x(00)80620-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
40
|
Klar U, Pletsch A, Skuballa W, Vorbrüggen H. Synthesis of potent 6-oxo and 9-fluoro-PGE1-derivatives and their biological properties. Bioorg Med Chem Lett 1992. [DOI: 10.1016/s0960-894x(00)80166-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|