Watts, E.
Heidenreich, D.
Tucker, E.
Raab, M.
Strebhardt, K.
Chesler, L.
Knapp, S.
Bellenie, B.
Hoelder, S.
(2019). Designing Dual Inhibitors of Anaplastic Lymphoma Kinase (ALK) and Bromodomain-4 (BRD4) by Tuning Kinase Selectivity. J med chem,
Vol.62
(5),
pp. 2618-2637.
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full text
Concomitant inhibition of anaplastic lymphoma kinase (ALK) and bromodomain-4 (BRD4) is a potential therapeutic strategy for targeting two key oncogenic drivers that co-segregate in a significant fraction of high-risk neuroblastoma patients, mutation of ALK and amplification of MYCN. Starting from known dual polo-like kinase (PLK)-1-BRD4 inhibitor BI-2536, we employed structure-based design to redesign this series toward compounds with a dual ALK-BRD4 profile. These efforts led to compound ( R)-2-((2-ethoxy-4-(1-methylpiperidin-4-yl)phenyl)amino)-7-ethyl-5-methyl-8-((4-methylthiophen-2-yl)methyl)-7,8-dihydropteridin-6(5 H)-one (16k) demonstrating improved ALK activity and significantly reduced PLK-1 activity, while maintaining BRD4 activity and overall kinome selectivity. We demonstrate the compounds' on-target engagement with ALK and BRD4 in cells as well as favorable broad kinase and bromodomain selectivity..
Hudson, L.
Mui, J.
Vázquez, S.
Carvalho, D.M.
Williams, E.
Jones, C.
Bullock, A.N.
Hoelder, S.
(2018). Novel Quinazolinone Inhibitors of ALK2 Flip between Alternate Binding Modes: Structure-Activity Relationship, Structural Characterization, Kinase Profiling, and Cellular Proof of Concept. J med chem,
Vol.61
(16),
pp. 7261-7272.
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full text
Structure-activity relationship and crystallographic data revealed that quinazolinone-containing fragments flip between two distinct modes of binding to activin receptor-like kinase-2 (ALK2). We explored both binding modes to discover potent inhibitors and characterized the chemical modifications that triggered the flip in binding mode. We report kinase selectivity and demonstrate that compounds of this series modulate ALK2 in cancer cells. These inhibitors are attractive starting points for the discovery of more advanced ALK2 inhibitors..
Woodward, H.L.
Innocenti, P.
Cheung, K.-.
Hayes, A.
Roberts, J.
Henley, A.T.
Faisal, A.
Mak, G.W.
Box, G.
Westwood, I.M.
Cronin, N.
Carter, M.
Valenti, M.
De Haven Brandon, A.
O'Fee, L.
Saville, H.
Schmitt, J.
Burke, R.
Broccatelli, F.
van Montfort, R.L.
Raynaud, F.I.
Eccles, S.A.
Linardopoulos, S.
Blagg, J.
Hoelder, S.
(2018). Introduction of a Methyl Group Curbs Metabolism of Pyrido[3,4- d]pyrimidine Monopolar Spindle 1 (MPS1) Inhibitors and Enables the Discovery of the Phase 1 Clinical Candidate N2-(2-Ethoxy-4-(4-methyl-4 H-1,2,4-triazol-3-yl)phenyl)-6-methyl- N8-neopentylpyrido[3,4- d]pyrimidine-2,8-diamine (BOS172722). J med chem,
Vol.61
(18),
pp. 8226-8240.
show abstract
Monopolar spindle 1 (MPS1) occupies a central role in mitosis and is one of the main components of the spindle assembly checkpoint. The MPS1 kinase is an attractive cancer target, and herein, we report the discovery of the clinical candidate BOS172722. The starting point for our work was a series of pyrido[3,4- d]pyrimidine inhibitors that demonstrated excellent potency and kinase selectivity but suffered from rapid turnover in human liver microsomes (HLM). Optimizing HLM stability proved challenging since it was not possible to identify a consistent site of metabolism and lowering lipophilicity proved unsuccessful. Key to overcoming this problem was the finding that introduction of a methyl group at the 6-position of the pyrido[3,4- d]pyrimidine core significantly improved HLM stability. Met ID studies suggested that the methyl group suppressed metabolism at the distant aniline portion of the molecule, likely by blocking the preferred pharmacophore through which P450 recognized the compound. This work ultimately led to the discovery of BOS172722 as a Phase 1 clinical candidate..
McGrath, S.
Tortorici, M.
Drouin, L.
Solanki, S.
Vidler, L.
Westwood, I.
Gimeson, P.
Van Montfort, R.
Hoelder, S.
(2017). Structure-Enabled Discovery of a Stapled Peptide Inhibitor to Target the Oncogenic Transcriptional Repressor TLE1. Chemistry,
Vol.23
(40),
pp. 9577-9584.
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full text
TLE1 is an oncogenic transcriptional co-repressor that exerts its repressive effects through binding of transcription factors. Inhibition of this protein-protein interaction represents a putative cancer target, but no small-molecule inhibitors have been published for this challenging interface. Herein, the structure-enabled design and synthesis of a constrained peptide inhibitor of TLE1 is reported. The design features the introduction of a four-carbon-atom linker into the peptide epitope found in many TLE1 binding partners. A concise synthetic route to a proof-of-concept peptide, cycFWRPW, has been developed. Biophysical testing by isothermal titration calorimetry and thermal shift assays showed that, although the constrained peptide bound potently, it had an approximately five-fold higher Kd than that of the unconstrained peptide. The co-crystal structure suggested that the reduced affinity was likely to be due to a small shift of one side chain, relative to the otherwise well-conserved conformation of the acyclic peptide. This work describes a constrained peptide inhibitor that may serve as the basis for improved inhibitors..
Innocenti, P.
Woodward, H.L.
Solanki, S.
Naud, S.
Westwood, I.M.
Cronin, N.
Hayes, A.
Roberts, J.
Henley, A.T.
Baker, R.
Faisal, A.
Mak, G.W.
Box, G.
Valenti, M.
De Haven Brandon, A.
O'Fee, L.
Saville, H.
Schmitt, J.
Matijssen, B.
Burke, R.
van Montfort, R.L.
Raynaud, F.I.
Eccles, S.A.
Linardopoulos, S.
Blagg, J.
Hoelder, S.
(2016). Rapid Discovery of Pyrido[3,4-d]pyrimidine Inhibitors of Monopolar Spindle Kinase 1 (MPS1) Using a Structure-Based Hybridization Approach. J med chem,
Vol.59
(8),
pp. 3671-3688.
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full text
Monopolar spindle 1 (MPS1) plays a central role in the transition of cells from metaphase to anaphase and is one of the main components of the spindle assembly checkpoint. Chromosomally unstable cancer cells rely heavily on MPS1 to cope with the stress arising from abnormal numbers of chromosomes and centrosomes and are thus more sensitive to MPS1 inhibition than normal cells. We report the discovery and optimization of a series of new pyrido[3,4-d]pyrimidine based inhibitors via a structure-based hybridization approach from our previously reported inhibitor CCT251455 and a modestly potent screening hit. Compounds in this novel series display excellent potency and selectivity for MPS1, which translates into biomarker modulation in an in vivo human tumor xenograft model..
Drouin, L.
McGrath, S.
Vidler, L.R.
Chaikuad, A.
Monteiro, O.
Tallant, C.
Philpott, M.
Rogers, C.
Fedorov, O.
Liu, M.
Akhtar, W.
Hayes, A.
Raynaud, F.
Müller, S.
Knapp, S.
Hoelder, S.
(2015). Structure enabled design of BAZ2-ICR, a chemical probe targeting the bromodomains of BAZ2A and BAZ2B. J med chem,
Vol.58
(5),
pp. 2553-2559.
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full text
The bromodomain containing proteins BAZ2A/B play essential roles in chromatin remodeling and regulation of noncoding RNAs. We present the structure based discovery of a potent, selective, and cell active inhibitor 13 (BAZ2-ICR) of the BAZ2A/B bromodomains through rapid optimization of a weakly potent starting point. A key feature of the presented inhibitors is an intramolecular aromatic stacking interaction that efficiently occupies the shallow bromodomain pockets. 13 represents an excellent chemical probe for functional studies of the BAZ2 bromodomains in vitro and in vivo..
Gurden, M.D.
Westwood, I.M.
Faisal, A.
Naud, S.
Cheung, K.-.
McAndrew, C.
Wood, A.
Schmitt, J.
Boxall, K.
Mak, G.
Workman, P.
Burke, R.
Hoelder, S.
Blagg, J.
Van Montfort, R.L.
Linardopoulos, S.
(2015). Naturally Occurring Mutations in the MPS1 Gene Predispose Cells to Kinase Inhibitor Drug Resistance. Cancer res,
Vol.75
(16),
pp. 3340-3354.
show abstract
Acquired resistance to therapy is perhaps the greatest challenge to effective clinical management of cancer. With several inhibitors of the mitotic checkpoint kinase MPS1 in preclinical development, we sought to investigate how resistance against these inhibitors may arise so that mitigation or bypass strategies could be addressed as early as possible. Toward this end, we modeled acquired resistance to the MPS1 inhibitors AZ3146, NMS-P715, and CCT251455, identifying five point mutations in the kinase domain of MPS1 that confer resistance against multiple inhibitors. Structural studies showed how the MPS1 mutants conferred resistance by causing steric hindrance to inhibitor binding. Notably, we show that these mutations occur in nontreated cancer cell lines and primary tumor specimens, and that they also preexist in normal lymphoblast and breast tissues. In a parallel piece of work, we also show that the EGFR p.T790M mutation, the most common mutation conferring resistance to the EGFR inhibitor gefitinib, also preexists in cancer cells and normal tissue. Our results therefore suggest that mutations conferring resistance to targeted therapy occur naturally in normal and malignant cells and these mutations do not arise as a result of the increased mutagenic plasticity of cancer cells..
Innocenti, P.
Woodward, H.
O'Fee, L.
Hoelder, S.
(2015). Expanding the scope of fused pyrimidines as kinase inhibitor scaffolds: synthesis and modification of pyrido[3,4-d]pyrimidines. Org biomol chem,
Vol.13
(3),
pp. 893-904.
show abstract
Fused pyrimidine cores are privileged kinase scaffolds, yet few examples of the 2-amino-pyrido[3,4-d]pyrimidine chemotype have been disclosed in the context of kinase inhibitor programs. Furthermore, no general synthetic route has been reported to access 2-amino-pyrido[3,4-d]pyrimidine derivatives. Here we report a versatile and efficient chemical approach to this class of molecules. Our strategy involves the concise preparation of 8-chloro-2-(methylthio)pyrido[3,4-d]pyrimidine intermediates and their efficient derivatisation to give novel compounds with potential as kinase inhibitors..
Innocenti, P.
Cheung, K.-.
Solanki, S.
Mas-Droux, C.
Rowan, F.
Yeoh, S.
Boxall, K.
Westlake, M.
Pickard, L.
Hardy, T.
Baxter, J.E.
Aherne, G.W.
Bayliss, R.
Fry, A.M.
Hoelder, S.
(2012). Design of potent and selective hybrid inhibitors of the mitotic kinase Nek2: structure-activity relationship, structural biology, and cellular activity. J med chem,
Vol.55
(7),
pp. 3228-3241.
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full text
We report herein a series of Nek2 inhibitors based on an aminopyridine scaffold. These compounds have been designed by combining key elements of two previously discovered chemical series. Structure based design led to aminopyridine (R)-21, a potent and selective inhibitor able to modulate Nek2 activity in cells..
Vidler, L.R.
Brown, N.
Knapp, S.
Hoelder, S.
(2012). Druggability analysis and structural classification of bromodomain acetyl-lysine binding sites. J med chem,
Vol.55
(17),
pp. 7346-7359.
show abstract
Bromodomains are readers of the epigenetic code that specifically bind acetyl-lysine containing recognition sites on proteins. Recently the BET family of bromodomains has been demonstrated to be druggable through the discovery of potent inhibitors, sparking an interest in protein-protein interaction inhibitors that directly target gene transcription. Here, we assess the druggability of diverse members of the bromodomain family using SiteMap and show that there are significant differences in predicted druggability. Furthermore, we trace these differences in druggability back to unique amino acid signatures in the bromodomain acetyl-lysine binding sites. These signatures were then used to generate a new classification of the bromodomain family, visualized as a classification tree. This represents the first analysis of this type for the bromodomain family and can prove useful in the discovery of inhibitors, particularly for anticipating screening hit rates, identifying inhibitors that can be explored for lead hopping approaches, and selecting proteins for selectivity screening..