Discovery of IRAK4 Inhibitors BAY1834845 (Zabedosertib) and BAY1830839.

Interleukin-1 receptor-associated kinase 4 (IRAK4) plays a critical role in innate inflammatory processes. Here, we describe the discovery of two clinical candidate IRAK4 inhibitors, BAY1834845 (zabedosertib) and BAY1830839, starting from a high-throughput screening hit derived from Bayer's compound library. By exploiting binding site features distinct to IRAK4 using an in-house docking model, liabilities of the original hit could surprisingly be overcome to confer both candidates with a unique combination of good potency and selectivity. Favorable DMPK profiles and activity in animal inflammation models led to the selection of these two compounds for clinical development in patients.

Enantioselective Total Synthesis of (-)-Finerenone Using Asymmetric Transfer Hydrogenation.

(-)-Finerenone is a nonsteroidal mineralocorticoid receptor antagonist currently in phase III clinical trials for the treatment of chronic kidney disease in type 2 diabetes. It contains an unusual dihydronaphthyridine core. We report a 6-step synthesis of (-)-finerenone, which features an enantioselective partial transfer hydrogenation of a naphthyridine using a chiral phosphoric acid catalyst with a Hantzsch ester. The process is complicated by the fact that the naphthyridine exists as a mixture of two atropisomers that react at different rates and with different selectivities. The intrinsic kinetic resolution was converted into a kinetic dynamic resolution at elevated temperature, which enabled us to obtain (-)-finerenone in both high yield and high enantioselectivity. DFT calculations have revealed the origin of selectivity.

Biotransformation of Finerenone, a Novel Nonsteroidal Mineralocorticoid Receptor Antagonist, in Dogs, Rats, and Humans, In Vivo and In Vitro.

Mass balance and biotransformation of finerenone, a nonsteroidal mineralocorticoid receptor antagonist, were investigated in four healthy male volunteers following a single oral administration of 10 mg (78 µCi) of [14C]finerenone and compared with data from studies in dogs and rats. The total recovery of the administered radioactivity was 101% in humans, 94.7% in dogs, and 95.2% in rats. In humans, radioactivity was mainly excreted renally (80%); in rats, it was primarily the biliary/fecal route (76%); and in dogs, excretion was more balanced. Finerenone was extensively metabolized in all species by oxidative biotransformation, with minor amounts of unchanged drug in excreta (humans: 1%; dogs, rats: <9%). In vitro studies suggested cytochrome P450 3A4 was the predominant enzyme involved in finerenone metabolism in humans. Primary metabolic transformation involved aromatization of the dihydronaphthyridine moiety of metabolite M1 as a major clearance pathway with a second oxidative pathway leading to M4. These were both prone to further oxidative biotransformation reactions. Naphthyridine metabolites (M1-M3) were the dominant metabolites identified in human plasma, with no on-target pharmacological activity. In dog plasma, finerenone and metabolite M2 constituted the major components; finerenone accounted almost exclusively for drug-related material in rat plasma. For metabolites M1-M3, axial chirality was observed, represented by two atropisomers (e.g., M1a and M1b). Analysis of plasma and excreta showed one atropisomer (a-series, >79%) of each metabolite predominated in all three species. In summary, the present study demonstrates that finerenone is cleared by oxidative biotransformation, mainly via naphthyridine derivatives.

Biocatalysis at Work: Applications in the Development of Sagopilone.

For the antitumour agent sagopilone, an epothilone analogue, a large-scale synthesis was developed to synthesise the active pharmaceutical ingredient for clinical trials, exploring enzymatic and microbial methods to produce chiral building blocks on a multi-kilogram scale. The three building blocks were identified as key intermediates in the synthesis and needed to be produced with high optical purity in yields higher than those previously published. The improved syntheses of two of these building blocks are detailed herein. For building block A, the chemical research synthesis was abandoned, and a novel chemical route was developed leading to building block A via an enzymatic hydrolysis process. For building blocks C, replacement of a chemical catalytic procedure by a microbial process meant that the development of a new starting material could be avoided, thereby accelerating the development process. For the clinical development process, a human metabolite of sagopilone was required as a reference. To accelerate the synthesis of the metabolite, no chemical synthesis was investigated; rather, we relied solely on oxidoreductases. The human metabolite of sagopilone was synthesised on a multi-gram scale in a single-step process using genetically engineered E. coli expressing human cytochrome P450 enzyme 2C19. The integration of enzymatic and microbial processes provided tools that enable the synthesis of highly functionalised intermediates and metabolites.

Discovery of BAY 94-8862: a nonsteroidal antagonist of the mineralocorticoid receptor for the treatment of cardiorenal diseases.

Aldosterone is a hormone that exerts manifold deleterious effects on the kidneys, blood vessels, and heart which can lead to pathophysiological consequences. Inhibition of the mineralocorticoid receptor (MR) is a proven therapeutic concept for the management of associated diseases. Use of the currently marketed MR antagonists spironolactone and eplerenone is restricted, however, due to a lack of selectivity in spironolactone and the lower potency and efficacy of eplerenone. Several pharmaceutical companies have implemented programs to identify drugs that overcome the known liabilities of steroidal MR antagonists. Herein we disclose an extended SAR exploration starting from cyano-1,4-dihydropyridines that were identified by high-throughput screening. Our efforts led to the identification of a dihydronaphthyridine, BAY 94-8862, which is a potent, selective, and orally available nonsteroidal MR antagonist currently under investigation in a clinical phase II trial.

Early MR lymphography with gadofluorine M in rabbits.

PURPOSE: To investigate the dose and time dependency of gadofluorine M for lymph node imaging and the detection of lymph node metastases in an animal model and to compare gadofluorine M with Gadomer (both, Schering, Berlin, Germany) for lymph node enhancement. MATERIALS AND METHODS: Enhancement of popliteal and iliac lymph nodes was studied in VX2 tumor-bearing rabbits before injection and at 5-120 minutes and 24 hours after intravenous bolus injection of 0.025, 0.05, and 0.1 mmol gadolinium per kilogram of body weight gadofluorine M (six rabbits) or 0.5 mmol/kg Gadomer (eight rabbits). Effects of treatment and time point at enhancement were evaluated with repeated measures analysis of variance. Means were separated with all-pairs comparison with Tukey-Kramer adjustment. After 1.5-T magnetic resonance (MR) imaging, lymph nodes were removed, and prepared sections were stained with hematoxylin-eosin for microscopic examination. RESULTS: MR images in VX2 tumor-bearing rabbits revealed rapid and strong signal intensity increase in the functional lymph node tissue by 15 minutes after intravenous injection of gadofluorine M. Maximum enhancement of 165%-309% was observed 60-90 minutes after injection (enhancement with 0.05 and 0.1 mmol/kg significantly different from that with 0.025 mmol/kg, P < or =.05). Metastatic tissue showed only slight enhancement at early time points, resulting in high-contrast differentiation between functional and metastatic tissue. Intravenous injection of the blood-pool agent Gadomer induced only short and inhomogeneous lymph node enhancement (enhancement significantly lower [P < or =.05] than that with gadofluorine M). CONCLUSION: Findings in the study showed that gadofluorine M produces rapid lymph node accumulation. Diagnosis of lymph node metastases was shown with intravenous injection of gadofluorine M with a minimum effective diagnostic dose of 0.025 mmol/kg.

Equilibrium, 1H and 13C NMR spectroscopy, and X-ray diffraction studies on the complexes Bi(DOTA)- and Bi(DO3A-Bu).

Several Bi(III) complexes are used in medicine as drugs. Bi(DO3A-Bu) has recently been proposed as a nonionic contrast agent in X-ray imaging (H(3)DO3A-Bu = 10-[2,3-dihydroxy-(1-hydroxymethyl)propyl]-1,4,7,10-tetraazacyclododecane-1,4,7,-triacetic acid). The solution equilibria and NMR structure and dynamics of Bi(DO3A-Bu) and of the similar Bi(DOTA)(-) have been investigated (H(4)DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid). The stability constants were determined with the study of the competition equilibria between Br(-) ions and the ligands DOTA or DO3A-Bu for the Bi(III) by spectrophotometry. The stability constants, obtained for Bi(DOTA)(-) and Bi(DO3A-Bu), are very high, log K = 30.3 and 26.8, respectively. Potentiometric titrations indicated the dissociation of one of the protons among the three alcoholic OH groups in Bi(DO3A-Bu). The dissociation constant is log K = 7.53 (0.09) indicating that at physiological pH about 50% of the species possess -1 charge. It was shown by (1)H and (13)C NMR spectroscopy that the OH group attached to the middle carbon atom of the "butriol" side chain is coordinated to the Bi(III) and starts to deprotonate at pH > 5.5. The crystal structure of NaBi(DOTA).H(2)O shows an octacoordinated arrangement of the donor atoms around the Bi(III), with no water in the inner sphere. The crystals belong to the centrosymmetric space group C2/c. The temperature dependent (1)H and (13)C NMR spectra indicate that both Bi(DOTA)(-) and Bi(DO3A-Bu)(-) complexes are fluxional. For Bi(DOTA), the Delta(deltadeltadeltadelta) right harpoon over left harpoon Lambda(lambdalambdalambdalambda) fluxionality was identified, and on the basis of the activation parameters, a synchronous motion was suggested for the fluxional motion resulting in the change of ring conformation and of the helicity of the complex. The transition state is supposed to be more symmetrical than the initial state. The deprotonated Bi(DO3A-Bu) has a highly asymmetric NMR structure in solution, and its fluxional motion is slower than that of Bi(DOTA)(-).