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Aldosterone synthase (CYP11B2) inhibitors have been explored in recent years as an alternative therapeutic option to mineralocorticoid receptor (MR) antagonists to reduce elevated aldosterone levels, which are associated with deleterious effects on various organ systems including the heart, vasculature, kidney, and central nervous system (CNS). A benzamide pyridine hit derived from a focused screen was successfully developed into a series of potent and selective 3-pyridyl isoindolin-1-ones CYP11B2 inhibitors. Our systematic structure-activity relationship study enabled us to identify unique structural features that result in high selectivity against the closely homologous cortisol synthase (CYP11B1). We evaluated advanced lead molecules, exemplified by compound 52, in an in vivo cynomolgus monkey acute adrenocorticotropic hormone (ACTH) challenge model and demonstrated a superior 100-fold in vivo selectivity against CYP11B1.

Inappropriately high levels of aldosterone are associated with many serious medical conditions, including renal and cardiac failure. A focused screen hit has been optimized into a potent and selective aldosterone synthase (CYP11B2) inhibitor with in vitro activity against rat, mouse, human, and cynomolgus monkey enzymes, showing a selectivity factor of 160 against cytochrome CYP11B1 in the last species. The novel tetrahydroisoquinoline compound (+)-(R)-6 selectively reduced aldosterone plasma levels in vivo in a dose-dependent manner in db/db mice and cynomolgus monkeys. The selectivity against CYP11B1 as predicted by cellular inhibition data and free plasma fraction translated well to Synacthen challenged cynomolgus monkeys up to a dose of 0.1 mg kg(-1). This compound, displaying good in vivo potency and selectivity in mice and monkeys, is ideally suited to perform mechanistic studies in relevant rodent models and to provide the information necessary for translation to non-human primates and ultimately to man.

The development of in silico and in vitro tools to estimate or predict the passive human skin permeation and distribution of new chemical entities, useful in dermal drug delivery, in absorption studies of toxic compounds, and in the cosmetics industry, is presented. In vitro permeation parameters were measured using the artificial membrane PAMPA-skin. The Volsurf approach was then applied to extract pertinent descriptors from molecular interaction fields characterizing the molecular structure of tested compounds. Two useful three-dimensional solvatochromic models able to predict PAMPA permeation parameters directly from the molecular structure were obtained using the partial least squares analysis. The models also provide valuable information to understand the link between physicochemical and structural properties of tested compounds and their interactions with the artificial membrane PAMPA-skin and can be useful to rapidly estimate their permeation through the human skin.