RESUMO
Herein, we describe the identification, chemical optimization, and preclinical characterization of novel soluble guanylate cyclase (sGC) stimulators. Given the very broad therapeutic opportunities for sGC stimulators, new tailored molecules for distinct indications with specific pharmacokinetics, tissue distribution, and physicochemical properties will be required in the future. Here, we report the ultrahigh-throughput (uHTS)-based discovery of a new class of sGC stimulators from an imidazo[1,2-a]pyridine lead series. Through the extensive and staggered optimization of the initial screening hit, liabilities such as potency, metabolic stability, permeation, and solubility could be substantially improved in parallel. These efforts resulted ultimately in the discovery of the new sGC stimulators 22 and 28. It turned out that BAY 1165747 (BAY-747, 28) could be an ideal treatment alternative for patients with hypertension, especially those not responding to standard anti-hypertensive therapy (resistant hypertension). BAY-747 (28) demonstrated sustained hemodynamic effects up to 24 h in phase 1 studies.
Assuntos
Guanilato Ciclase , Hipertensão , Humanos , Guanilil Ciclase Solúvel/metabolismo , Guanilato Ciclase/metabolismo , Hipertensão/tratamento farmacológico , Vasodilatadores , Piridinas/farmacologia , Piridinas/uso terapêutico , Óxido Nítrico/metabolismoRESUMO
PURPOSE: Prostate-specific membrane antigen (PSMA) is a transmembrane protein overexpressed in prostate cancer and is therefore being explored as a biomarker for diagnosing and staging of the disease. Here we report preclinical data on BAY 1075553 (a 9:1 mixture of (2S,4S)- and (2R,4S)-2-[(18)F]fluoro-4-phosphonomethyl-pentanedioic acid), a novel (18)F-labelled small molecule inhibitor of PSMA enzymatic activity, which can be efficiently synthesized from a direct radiolabelling precursor. METHODS: The (18)F-radiolabelled stereoisomers of 2-[(18)F]fluoro-4-(phosphonomethyl)-pentanedioic acid were synthesized from their respective isomerically pure precursors dimethyl 2-{[bis(benzyloxy)phosphoryl]methyl}-4-(tosyloxy)pentanedioate. In vivo positron emission tomography (PET) imaging and biodistribution studies were conducted in mice bearing LNCaP, 22Rv1 and PC-3 tumours. Pharmacokinetic parameters and dosimetry estimates were calculated based on biodistribution studies in rodents. For non-clinical safety assessment (safety pharmacology, toxicology) to support a single-dose human microdose study, off-target effects in vitro, effects on vital organ functions (cardiovascular in dogs, nervous system in rats), mutagenicity screens and an extended single-dose study in rats were conducted with the non-radioactive racemic analogue of BAY 1075553. RESULTS: BAY 1075553 showed high tumour accumulation specific to PSMA-positive tumour-bearing mice and was superior to other stereoisomers tested. Fast clearance of BAY 1075553 resulted overall in low background signals in other organs except for high uptake into kidney and bladder which was mainly caused by renal elimination of BAY 1075553. A modest uptake into bone was observed which decreased over time indicating organ-specific uptake as opposed to defluorination of BAY 1075553 in vivo. Biodistribution studies found highest organ doses for kidneys and the urinary bladder wall resulting in a projected effective dose (ED) in humans of 0.0219 mSv/MBq. Non-clinical safety studies did not show off-target activity, effects on vital organs function or dose-dependent adverse effects. CONCLUSION: BAY 1075553 was identified as a promising PET tracer for PSMA-positive prostate tumours in preclinical studies. BAY 1075553 can be produced using a robust, direct radiosynthesis procedure. Pharmacokinetic, toxicology and safety pharmacology studies support the application of BAY 1075553 in a first-in-man microdose study with single i.v. administration.
Assuntos
Radioisótopos de Flúor , Glutamato Carboxipeptidase II/antagonistas & inibidores , Glutaratos , Organofosfonatos , Tomografia por Emissão de Pósitrons/métodos , Neoplasias da Próstata/diagnóstico por imagem , Compostos Radiofarmacêuticos , Animais , Antígenos de Superfície , Cães , Feminino , Glutaratos/efeitos adversos , Glutaratos/farmacocinética , Glutaratos/farmacologia , Humanos , Marcação por Isótopo , Masculino , Camundongos , Organofosfonatos/efeitos adversos , Organofosfonatos/farmacocinética , Organofosfonatos/farmacologia , Traçadores Radioativos , Radioquímica , Compostos Radiofarmacêuticos/efeitos adversos , Compostos Radiofarmacêuticos/farmacocinética , Compostos Radiofarmacêuticos/farmacologia , Ratos , Segurança , EstereoisomerismoRESUMO
For prostate cancer, prostate specific membrane antigen (PSMA) has been identified as a diagnostic and therapeutic target. Fluorinated derivatives of 2-(phosphonomethyl)pentanedioic acid were designed and synthesized to explore whether this fluorine-substituent is tolerated in the pentanedioic acid moiety that is common to almost all PSMA targeting small molecule inhibitors. The binding affinities of the racemic and individual stereoisomers of 2-fluoro-4-(phosphonomethyl)pentanedioic acid were determined and showed that the introduction of fluorine was well tolerated. The radiosynthesis of the analogous 2-[(18)F]fluoro-4-(phosphonomethyl)pentanedioic acid was developed and evaluated in vivo with the PSMA positive LNCaP human prostate cancer cell. The biological results demonstrated specific binding of the tracer to PSMA positive tumors in mice. These results warrant the further evaluation of this class of compounds as radiolabeled tracers for the detection and staging of prostate cancer.
Assuntos
Diagnóstico por Imagem , Glutamato Carboxipeptidase II/antagonistas & inibidores , Compostos Organofosforados/química , Neoplasias da Próstata/diagnóstico , Compostos Radiofarmacêuticos , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Modelos Químicos , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Neoplasias da Próstata/metabolismo , Radioquímica , Estereoisomerismo , Distribuição Tecidual , Tomografia Computadorizada por Raios X , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The first total synthesis of the macrolactone antibiotic branimycin (4) has been described. The key disconnection leads to a cis-dehydrodecalone core and a polyketide side chain which are connected via organometallic addition. The dehydrodecalone core was targeted via altogether five different approaches featuring various kinds of chiral elements and ring-closing methodology. In the end the most successful method starting from diepoxynaphthalene 109 was chosen to carry on with the synthesis. Thus the oxygen functions and carbon appendages were introduced via organometallic desymmetrization reactions to generate epoxy ketone 107, to which vinyl iodide 11 was added after conversion into the organolithium species. The synthesis was completed by introducing the ester side chain via Michael addition and subsequent macrolactonization.
Assuntos
Antibacterianos/síntese química , Macrolídeos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Macrolídeos/química , Macrolídeos/farmacologia , Estrutura Molecular , EstereoisomerismoRESUMO
The cis-decalin core 2 of the antibiotic branimycin has been prepared by desymmetrization of diepoxynaphthalene 4. The key steps involve two successive S(N)' opening of the oxa-bridges. An improved procedure for the synthesis of 4 is also described.