Daniel John Russell

Discovery of (+)-N-(3-aminopropyl)-N-[1-(5-benzyl-3-methyl-4-oxo-[1,2]thiazolo[5,4-d]pyrimidin-6-yl)-2-methylpropyl]-4-methylbenzamide (AZD4877), a kinesin spindle protein inhibitor and potential anticancer agent.

Structure-activity relationship analysis identified (+)-N-(3-aminopropyl)-N-[1-(5-benzyl-3-methyl-4-oxo-[1,2]thiazolo[5,4-d]pyrimidin-6-yl)-2-methylpropyl]-4-methylbenzamide (AZD4877), from a series of novel kinesin spindle protein (KSP) inhibitors, as exhibiting both excellent biochemical potency and pharmaceutical properties suitable for clinical development. The selected compound arrested cells in mitosis leading to the formation of the monopolar spindle phenotype characteristic of KSP inhibition and induction of cellular death. A favorable pharmacokinetic profile and notable in vivo efficacy supported the selection of this compound as a clinical candidate for the treatment of cancer.

Potent and Selective Inhibitors of CK2 Kinase Identified through Structure-Guided Hybridization

In this paper we describe a series of 3-cyano-5-aryl-7-aminopyrazolo[1,5-a]pyrimidine hits identified by kinase-focused subset screening as starting points for the structure-based design of conformationally constrained 6-acetamido-indole inhibitors of CK2. The synthesis, SAR, and effects of this novel series on Akt signaling and cell proliferation in vitro are described.

Discovery of novel hedgehog antagonists from cell-based screening: Isosteric modification of p38 bisamides as potent inhibitors of SMO

Cell-based subset screening of compounds using a Gli transcription factor reporter cell assay and shh stimulated cell differentiation assay identified a series of bisamide compounds as hedgehog pathway inhibitors with good potency. Using a ligand-based optimization strategy, heteroaryl groups were utilized as conformationally restricted amide isosteres replacing one of the amides which significantly increased their potency against SMO and the hedgehog pathway while decreasing activity against p38α kinase. We report herein the identification of advanced lead compounds such as imidazole 11c and 11f encompassing good p38α selectivity, low nanomolar potency in both cell assays, excellent physiochemical properties and in vivo pharmacokinetics.

Towards the next generation of dual Bcl-2/Bcl-xL inhibitors.

Structural modifications of the left-hand side of compound 1 were identified which retained or improved potent binding to Bcl-2 and Bcl-xL in in vitro biochemical assays and had strong activity in an RS4;11 apoptotic cellular assay. For example, sulfoxide diastereomer 13 maintained good binding affinity and comparable cellular potency to 1 while improving aqueous solubility. The corresponding diastereomer (14) was significantly less potent in the cell, and docking studies suggest that this is due to a stereochemical preference for the RS versus SS sulfoxide. Appending a dimethylaminoethoxy side chain (27) adjacent to the benzylic position of the biphenyl moiety of 1 improved cellular activity by approximately three-fold, and this activity was corroborated in cell lines overexpressing Bcl-2 and Bcl-xL.

Abstract B100: Structure-based design of AZ7732 a novel in vivo active beta-alanine-derived pan-IAP inhibitor.

Both monomeric and dimeric SMAC (Second Mitochondria-derived Activator of Caspaces) mimetics acting as IAP (Inhibitor of apoptosis proteins) anatgonists have been reported in the clinic as well as extensively in the literature (1). The first four amino acids in the N-terminal of SMAC (AVPI) are critical for binding to IAP proteins. Reported medicinal chemistry exploration of the AVPI template has primarily consisted of variation to the VPI position in the amino-terminal of the SMAC peptide. Structural illucidation of XIAP bound to IAP inhibitors has revealed a critical role for the alanine with dense hydrogen bonding, electrostatic and hydrophibic complementarity with the protein. To our knowledge, exploration of alanine modifications has been limited and generally led to significant reduction in potency. Using the molecular modeling software SuperStar(2), we investigated the publically available co-crystal structures of Smac-mimetics with cIAP1 and hypothesized that homologating the basic amine might be tolerated. Applying this strategy, we report on the successful transfer of a beta-alanine warhead to a number of monomeric scaffolds. The resulting novel monomers maintained cIAP1/2 potency albeit with a reduction in xIAP potency. We report here the first co-crystal structure of xIAP baculoviral IAP repeat 3 domain (BIR3) with a beta-alanine derived monomer. Examination of the binding site contacts in the co-crystal structure provided further insight into the optimization of the warhead. Herein we describe the synthesis, SAR and SPR of this novel warhead and the discovery of beta-alanine derived pan-IAP inhibitors. We show that the SAR can be transferred to dimers and is invariant to the position of dimerization. We report our efforts to optimize the series and mitigate Cyp3A4 inhibition. This work led to the discovery of AZ7732, a novel dimeric SMAC-mimetic; a pan inhibitor of IAPs (cIAP BIR3 IC50 = 12 nM, XIAP BIR3 IC50 = 13 nM, and XIAP BIR2 IC50 = 30 nM); potent in cells as a single agent (MDA-MB231 cIAP degradation IC50 = 0.2 nM, GI50 = 0.4 nM) and is synergistic in vitro in combination with gemcitabine. AZ7732 has favorable in vivo PK with physical properties suitable for IV dosing. AZ7732 is active in vivo as a single agent. Once weekly dosing in MDA-MB231 led to dose-dependent tumor growth inhibition with stasis achieved at 2.5 mpk, ¼ MTD. In conclusion, Structure-based design and medicinal chemistry efforts have successfully identified novel monomeric and dimeric SMAC mimetics leading to the discovery of a novel in vivo active dimeric pan-IAP inhibitor. (1) Fulda et al, Nat. Rev. Drug Disc., 11, 109-123, 2012. (2) M. L. Verdonk, et al, J. Mol. Biol., 289, 1093-1108, 1999 Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B100. Citation Format: Jamal C. Saeh, Brian Aquila, Daniel Russell, Edward Hennessy, Alex Hird, Melissa Vasbinder, Andrew Ferguson, Bin Yang, Maureen Hattersley, Naomi Laing, Terry MacIntyre, Troy Patterson, Galina Repik, Michael Rooney, Haiyun Wang, Dave Witson, Li Sha, Donald Cook, Paula Lewis, John Lee, Danyang Li, Victor Kamhi, Vibha Oza, Charles Omer. Structure-based design of AZ7732 a novel in vivo active beta-alanine-derived pan-IAP inhibitor. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B100.

Abstract 2461: Design and synthesis of AZD3463, a novel orally bioavailable dual ALK and IGF1R inhibitor, inhibits growth of crizotinib resistance cell lines with multiple mechanisms of acquired resistance.

Although the ALK inhibitor crizotinib has clinical efficacy in selected ALK positive NSCLC patients, the majority of patients who initially respond eventually relapse. Several mechanisms of resistance have been proposed including amplification, resistance mutations, as well as alternative pathway drivers including EGFR, cKIT and IGF1R. We report here the discovery of a novel scaffold of ALK inhibitors and optimization effort that led to the discovery of AZD3463 a novel dual in vivo active ALK and IGF1R inhibitor. An in house subset screening of kinase inhibitors and de novo studies identified 4-(1H-indol-3-yl)pyrimidin-2-amine analogs as potent ALK inhibitors. Modeling studies were utilized to guide the SAR strategy around the aminopyrimidine group which afforded several lead compounds. Early SAR efforts quickly determined that smaller substituents, chloro and methyl, were optimal in the C5 position of the pyrimidine, and that aniline is preferred over several other amino heterocycles investigated. Parallel medicinal chemistry strategies were executed for the optimization of the aniline and indole. These studies suggested that a 2,4-substituted aniline provided optimal potency and selectivity in conjunction with a variety of heterocycles in C4 position of the pyrimdine. Cyclic amines in the C4 position of the aniline led to simultaneous improvement of potency and metabolic stability. The inhibition of IGF1R in vitro was maintained and modulation of glucose levels in vivo was observed with the optimized compounds and AZD3463. AZD3463 demonstrated superior potency to crizotinib in vivo (H3122 PD unbound EC50=0.16 nM). In summary, detailed SAR studies were executed on the 4-(1H-indol-3-yl)pyrimidin-2-amine template that produced potent inhibitors of ALK with improved physical chemical and ADME properties, and identified AZD3463, a novel equipotent ALK and IGF1R inhibitor, potent in ALK-driven preclinical models and in a variety of crizotinib-resistant models. We present herein the design and synthesis of AZD3463 as well as its overall properties. Citation Format: Jamal C. Saeh, Bin Yang, Tim Pontz, Kumar Thakur, Bo Peng, Lisa Drew, Caroline Rivard, Dan Widzowski, Jane Cheng, Douglas Ferguson, Brenda McDermott, Minhui Shen, John McNulty, Ryohei Katayama, Jeffrey Engleman, Alice Shaw, Daniel Russell, Graeme Smith. Design and synthesis of AZD3463, a novel orally bioavailable dual ALK and IGF1R inhibitor, inhibits growth of crizotinib resistance cell lines with multiple mechanisms of acquired resistance. [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 2461. doi:10.1158/1538-7445.AM2013-2461

Abstract 2916: Discovery of pyrazolimidazopyridine compounds as potent in vitro and in vivo anaplastic lymphoma kinase inhibitors

Translocations linking anaplastic lymphoma kinase (ALK) to multiple fusion partners were identified in anaplastic large cell lymphoma (ALCL), inflammatory myofibroblastic tumors, esophageal squamous cell carcinomas, neuroblastoma, and in non small cell lung cancer (NSCLC). This fusion leads to constitutive activation of ALK and has potent transforming activity. The recent approval of Crizotinib validated clinically the usefulness of treating EML4-ALK +ve patients with an Alk inhibitor. We report two novel series of compounds that potently inhibit ALK both in vitro and in vivo. Two series of pyrazolimidazolpyridine compounds, with good physical properties, were identified as part of our screening effort as potent ALK inhibitors in ALK enzyme assays. Subsequent testing of the mode of action of these compounds in Del cell lines containing NPM-ALK fusions demonstrated strong inhibition of phospho-ALK. In vivo, oral administration of 10 mg/kg of a pyrazolimidazopyridine compound in a Del xenograft model in SCID mice resulted in greater than 90% inhibition of phospho-ALK over 6 hours. In conclusion, we have identified two series of pyrazolimidazopyridine compounds as potent ALK inhibitors both in vitro and in vivo. 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 2916. doi:1538-7445.AM2012-2916

Abstract 3910: Lead optimization of a series of 5-aminopyrazol-imidazopyridine compounds as potent anaplastic lymphoma kinase inhibitors active against clinically relevant ALK mutations

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Despite the success of Crizotinib in treating NSCLC patients with EML4-ALK fusions, cancers eventually develop resistance via a variety of mechanisms including mutations in the ATP binding site of the kinase domain. A series of 5-aminopyrazol-imidazopyridine compounds were identified to potently inhibit anaplastic lymphoma kinase and were found to be active against a number of mutations in vitro but suffered from strong Cyp inhibition and were found to be metabolically unstable by incubation in human hepatocytes and microsomes. Installation of a pyrimary alcohol group on the heteroaryl ethyl group of the scaffold consistently improved Cyp3A4 liability, and led to improvement in physical and DMPK properties as well as improvement of their metabolic stability in human Heps. The lead compound from this series was orally administrated to SCID mice in a Del xenograft model and achieved greater than 90% phospho-ALK inhibition over 6 hours post dose at 10 mg/kg dose. The lead compound was subsequently tested against Crizotinib-resistant ALK mutations in enzyme assays, and was shown to inhibit the clinically relevant ALK mutations, including L1196M. In enzyme assays, it was inactive against G1269S mutation, consistent with modeling studies. Subsequent profiling in an FDCP cell line over expressing ALK G1269S mutation showed potent anti-proliferative activity, suggesting off-target activity. Further characterization of this series identified AurB inhibition to be a key cell cycle kinase responsible for the off-target activity in the engineered cell line. The off target activity hinders it from assessing the primary pharmacology responsible for its preclinical efficacy in disease relevant models. In conclusion, we have identified a novel orally bioavailable compound that is a potent dual active ALK and AurB inhibitor that is active against clinically-relevant gatekeeper mutant. 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 3910. doi:1538-7445.AM2012-3910