Monocyte chemoattracant-1 (MCP-1) stimulates leukocyte chemotaxis to inflammatory sites, such as rheumatoid arthritis, atherosclerosis, and asthma, by use of the MCP-1 receptor, CCR2, a member of the G-proteincoupled seven-transmembrane receptor superfamily. These studies identified a family of antagonists, spiropiperidines. One of the more potent compounds blocks MCP-1 binding to CCR2 with a K d of 60 nM, but it is unable to block binding to CXCR1, CCR1, or CCR3. These compounds were effective inhibitors of chemotaxis toward MCP-1 but were very poor inhibitors of CCR1-mediated chemotaxis. The compounds are effective blockers of MCP-1-driven inhibition of adenylate cyclase and MCP-1-and MCP-3-driven cytosolic calcium influx; the compounds are not agonists for these pathways. We showed that glutamate 291 (Glu 291 ) of CCR2 is a critical residue for high affinity binding and that this residue contributes little to MCP-1 binding to CCR2. The basic nitrogen present in the spiropiperidine compounds may be the interaction partner for Glu 291 , because the basicity of this nitrogen was essential for affinity; furthermore, a different class of antagonists, a class that does not have a basic nitrogen (2-carboxypyrroles), were not affected by mutations of Glu 291 . In addition to the CCR2 receptor, spiropiperidine compounds have affinity for several biogenic amine receptors. Receptor models indicate that the acidic residue, Glu 291, from transmembrane-7 of CCR2 is in a position similar to the acidic residue contributed from transmembrane-3 of biogenic amine receptors, which may account for the shared affinity of spiropiperidines for these two receptor classes. The models suggest that the acid-base pair, Glu 291 to piperidine nitrogen, anchors the spiropiperidine compound within the transmembrane ovoid bundle. This binding site may overlap with the space required by MCP-1 during binding and signaling; thus the small molecule ligands act as antagonists. An acidic residue in transmembrane region 7 is found in most chemokine receptors and is rare in other serpentine receptors. The model of the binding site may suggest ways to make new small molecule chemokine receptor antagonists, and it may rationalize the design of more potent and selective antagonists.Chemokines are a large family of small proteins that mediate attraction of leukocytes to inflammatory sites (1-3). The chemokine family shares a common pattern of disulfide bonds and a common overall tertiary structure as shown in solution or crystallographically determined structures (4 -6). The chemokine family is divided into four subfamilies based on the number of residues between the first and second cysteine. Among the chemokines, the CC chemokine monocyte chemoattracant-1 (MCP-1) 1 has received a great deal of attention because of its involvement in diseases. MCP-1 expression is elevated in the inflamed synovium of rheumatoid arthritis, and its expression is reduced by anti-arthritic drugs (7,8). Other work has shown that MCP-1 is elevated in asthmatic patients; the am...

The work in this paper describes the optimization of the 3-(3-phenyl-3H-imidazo[4,5-b]pyridin-2-yl)pyridin-2-amine chemical series as potent, selective allosteric inhibitors of AKT kinases, leading to the discovery of ARQ 092 (21a). The cocrystal structure of compound 21a bound to full-length AKT1 confirmed the allosteric mode of inhibition of this chemical class and the role of the cyclobutylamine moiety. Compound 21a demonstrated high enzymatic potency against AKT1, AKT2, and AKT3, as well as potent cellular inhibition of AKT activation and the phosphorylation of the downstream target PRAS40. Compound 21a also served as a potent inhibitor of the AKT1-E17K mutant protein and inhibited tumor growth in a human xenograft mouse model of endometrial adenocarcinoma.

Dysregulation of Fibroblast Growth Factor Receptor (FGFR) signaling through amplifications, mutations, and gene fusions has been implicated in a broad array of cancers (e.g. liver, gastric, ovarian, endometrial, and bladder). ARQ 087 is a novel, ATP competitive, small molecule, multi-kinase inhibitor with potent in vitro and in vivo activity against FGFR addicted cell lines and tumors. Biochemically, ARQ 087 exhibited IC50 values of 1.8 nM for FGFR2, and 4.5 nM for FGFR1 and 3. In cells, inhibition of FGFR2 auto-phosphorylation and other proteins downstream in the FGFR pathway (FRS2α, AKT, ERK) was evident by the response to ARQ 087 treatment. Cell proliferation studies demonstrated ARQ 087 has anti-proliferative activity in cell lines driven by FGFR dysregulation, including amplifications, fusions, and mutations. Cell cycle studies in cell lines with high levels of FGFR2 protein showed a positive relationship between ARQ 087 induced G1 cell cycle arrest and subsequent induction of apoptosis. In addition, ARQ 087 was effective at inhibiting tumor growth in vivo in FGFR2 altered, SNU-16 and NCI-H716, xenograft tumor models with gene amplifications and fusions. ARQ 087 is currently being studied in a phase 1/2 clinical trial that includes a sub cohort for intrahepatic cholangiocarcinoma patients with confirmed FGFR2 gene fusions (NCT01752920).

This paper describes the implementation of a biochemical and biophysical screening strategy to identify and optimize small molecule Akt1 inhibitors that act through a mechanism distinct from that observed for kinase domain ATP-competitive inhibitors. With the aid of an unphosphorylated Akt1 cocrystal structure of 12j solved at 2.25 Å, it was possible to confirm that as a consequence of binding these novel inhibitors, the ATP binding cleft contained a number of hydrophobic residues that occlude ATP binding as expected. These Akt inhibitors potently inhibit intracellular Akt activation and its downstream target (PRAS40) in vitro. In vivo pharmacodynamic and pharmacokinetic studies with two examples, 12e and 12j, showed the series to be similarly effective at inhibiting the activation of Akt and an additional downstream effector (p70S6) following oral dosing in mice.

Chiral triols 1-3 ('tris(hydroxymethy1)methane' derivatives), prepared from (R)-3-hydroxybutanoic acid and aldehydes, are used as center pieces of dendrimers. The triols may be employed as such or after attachment of spacers containing alkyl or aryl moieties (see 5 and 7). The branches combined with the original or elongated triols are those first reported by FrPchet (9 -12, benzyl ethers of 3,5-dihydroxybenzyl alcohol and bromide). In this way, 1st-, 2nd-, and 3rd-generation chiral dendrimers without (1%15), or with aliphatic (16-18) or aromatic (19-21) spacers are prepared. The molecular weights range from 447 to 2716 Dalton. Two of the chiral triols, i.e., 2 and 3, are used as center pieces for chiral dendrimers containing 6 NH2, or 6 and 12 NO, groups on the periphery (22-27), with 3,5-dinitrobenzoyl chloride as the branching unit. All compounds thus synthesized are of course monodisperse and are fully characterized. In some cases, the optical activity of the dendrimers indicates that conformationally chiral substructures might be present. The NH2-and N02-substituted compounds avidly clathrate smaller molecules; they are sorbents exchanging host molecules through the gas phase.