Search

A series of 3-aryl(( S )-3-fluoropyrrolidin-1-yl)butanoic acids were developed as potent orally bioavailable α v β 6 integrin inhibitors. Starting from a zwitterionic peptidomimetic series optimized for inhaled administration, the balancing of potency and passive permeability to achieve suitable oral agents through modification and exploration of aryl substituents and p K a of the central cyclic amine is described. ( S )-4-(( S )-3-Fluoro-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)pyrrolidin-1-yl)-3-(3-(2-methoxyethoxy)phenyl)butanoic acid was found to have highly desirable oral pharmacokinetic profiles in rat, dog, and minipig, with low to moderate clearance (26%, 7%, and 18% liver blood flow, respectively), moderate volumes of distribution (3.6, 1.4, and 0.9 L/kg, respectively), high to complete oral bioavailabilities, high α v β 6 integrin potency of pIC50 of 8.0, and high solubility in physiological media (>2 mg/mL). Equating to the estimated human dose range of 10-75 mg b.i.d. to achieve 90% α v β 6 target engagement at C min , it was selected for further investigation as a potential therapeutic agent for the treatment of idiopathic pulmonary fibrosis.

3D electron diffraction (3DED) is increasingly employed to determine molecular and crystal structures from micro-crystals. Indomethacin is a well known, marketed, small-molecule non-steroidal anti-inflammatory drug with eight known polymorphic forms, of which four structures have been elucidated to date. Using 3DED, we determined the structure of a new ninth polymorph, σ, found within an amorphous solid dispersion, a product formulation sometimes used for active pharmaceutical ingredients with poor aqueous solubility. Subsequently, we found that σ indomethacin can be produced from direct solvent evaporation using dichloromethane. These results demonstrate the relevance of 3DED within drug development to directly probe product formulations., (open access.)

The profound efficacy, yet associated toxicity of pan-BET inhibitors is well documented. The possibility of an ameliorated safety profile driven by significantly selective (>100-fold) inhibition of a subset of the eight bromodomains is enticing, but challenging given the close homology. Herein, we describe the X-ray crystal structure-directed optimization of a novel weak fragment ligand with a pan-second bromodomain (BD2) bias, to potent and highly BD2 selective inhibitors. A template hopping approach, enabled by our parallel research into an orthogonal template ( 15 , GSK046), was the basis for the high selectivity observed. This culminated in two tool molecules, 20 (GSK620) and 56 (GSK549), which showed an anti-inflammatory phenotype in human whole blood, confirming their cellular target engagement. Excellent broad selectivity, developability, and in vivo oral pharmacokinetics characterize these tools, which we hope will be of broad utility to the field of epigenetics research.

The heterodimeric transmembrane αv integrin receptors have recently emerged as potential targets for the treatment of idiopathic pulmonary fibrosis. Herein, we describe how subtle modifications of the central aromatic ring of a series of phenylbutyrate-based antagonists of the vitronectin receptors αvβ3 and αvβ5 significantly change the biological activities against αvβ6 and αvβ8. This resulted in the discovery of a pan αv antagonist (compound 39 , 4-40 nM for the integrin receptors named above) possessing excellent oral pharmacokinetic properties in rats (with a clearance of 7.6 mL/(min kg) and a bioavailability of 97%).

2-Aminoimidazoles represent useful synthons for incorporation into medicinal compounds. They provide hydrogen bonding loci, water solubilizing properties and convenient handles for further synthetic elaboration. The rapid and facile generation of diverse 2-aminoimidazoles via tandem addition cyclization reaction of vinyl azides and cyanamide has been investigated. These reactions proceeded through either thermal or photochemical activation of vinyl azides and demonstrated wide substrate scope. In the photochemical reaction, blue light (456 nm) alone triggered photolysis of the azide without the addition of a photocatalyst. Possible reaction mechanisms in the context of substrate reactivity are discussed.

The leishmaniases are diseases that affect millions of people across the world, in particular visceral leishmaniasis (VL) which is fatal unless treated. Current standard of care for VL suffers from multiple issues and there is a limited pipeline of new candidate drugs. As such, there is a clear unmet medical need to identify new treatments. This paper describes the optimization of a phenotypic hit against Leishmania donovani, the major causative organism of VL. The key challenges were to balance solubility and metabolic stability while maintaining potency. Herein, strategies to address these shortcomings and enhance efficacy are discussed, culminating in the discovery of preclinical development candidate GSK3186899/DDD853651 (1) for VL.

CXCR2 has emerged as a therapeutic target for not only peripheral inflammatory diseases but also neurological abnormalities in the central nervous system (CNS). Herein, we describe the discovery of a novel 1-cyclopentenyl-3-phenylurea series as potent and CNS penetrant CXCR2 antagonists. Extensive SAR studies, wherein molecules' property forecast index (PFI) was carefully optimized for overall balanced developability profiles, led to the discovery of the advanced lead compound 68 with a desirable PFI. Compound 68 demonstrated good in vitro pharmacology with excellent selectivity over CXCR1 and other chemokine receptors. Rat and dog pharmacokinetics (PK) revealed good oral bioavailability, high oral exposure, and desirable elimination half-life of the compound in both species. In addition, the compound demonstrated dose-dependent efficacy in the in vivo pharmacology neutrophil infiltration "air pouch" model in rodents after oral administration. Further, compound 68 is a CNS penetrant molecule with high unbound fraction in brain tissue.