RESUMO
AIMS: To assess the cardiovascular (CV) safety of oral semaglutide, the first tablet formulation of a glucagon-like peptide-1 receptor agonist. MATERIALS AND METHODS: PIONEER 6 is a multinational, randomized, placebo-controlled, double-blind trial in patients with type 2 diabetes at high risk of CV events (defined as being aged ≥50 years and having established CV disease [CVD] or moderate [stage 3] chronic kidney disease [CKD], or being aged ≥60 years with ≥1 other CV risk factor). Patients were randomized to once-daily oral semaglutide (up to 14 mg) or placebo added to standard of care. The primary composite endpoint is time to first occurrence of CV death or non-fatal myocardial infarction or non-fatal stroke. The primary hypothesis was to exclude an excess in CV risk with oral semaglutide by assessing non-inferiority versus placebo for the primary endpoint (non-inferiority margin of 1.8 for the upper boundary of the 95% confidence interval of the hazard ratio). PIONEER 6 is event-driven, with follow-up continuing until accrual of at least 122 primary outcome events. There is no pre-defined minimal duration. RESULTS: Overall, 3183 patients have been enrolled (mean age 66.1 years, 31.6% females) in 214 sites across 21 countries. At baseline, the mean duration of diabetes was 14.9 years, mean glycated haemoglobin concentration was 66 mmol/mol (8.2%), and 84.6% of patients had established CVD/moderate CKD. CONCLUSIONS: PIONEER 6 will provide evidence regarding the CV safety of oral semaglutide in patients with type 2 diabetes and high CV risk.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Sistema Cardiovascular/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Peptídeos Semelhantes ao Glucagon/administração & dosagem , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Angiopatias Diabéticas/epidemiologia , Angiopatias Diabéticas/prevenção & controle , Método Duplo-Cego , Feminino , Peptídeos Semelhantes ao Glucagon/efeitos adversos , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/efeitos adversos , Masculino , Metformina/administração & dosagem , Metformina/efeitos adversos , Pessoa de Meia-Idade , Placebos , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/tratamento farmacológico , Insuficiência Renal Crônica/epidemiologiaRESUMO
The design, synthesis, and pharmacological characterization of a highly potent and selective glutamate GluR5 agonist is reported. (S)-2-Amino-3-((RS)-3-hydroxy-8-methyl-7,8-dihydro-6H-cyclohepta[d]isoxazol-4-yl)propionic acid (5) is the 8-methyl analogue of (S)-2-amino-3-(3-hydroxy-7,8-dihydro-6H-cyclohepta[d]isoxazol-4-yl)propionic acid ((S)-4-AHCP, 4). Compound 5 displays an improved selectivity profile compared to 4. A versatile stereoselective synthetic route for this class of compounds is presented along with the characterization of the binding affinity of 5 to ionotropic glutamate receptors (iGluRs). Functional characterization of 5 at cloned iGluRs using a calcium imaging assay and voltage-clamp recordings show a different activation of GluR5 compared to (S)-glutamic acid (Glu), kainic acid (KA, 1), and (S)-2-amino-3-(3-hydroxy-5-tert-butyl-4-isoxazolyl)propionic acid ((S)-ATPA, 3) as previously demonstrated for 4. An X-ray crystallographic analysis of 4 and computational analyses of 4 and 5 bound to the GluR5 agonist binding domain (ABD) are presented, including a watermap analysis, which suggests that water molecules in the agonist binding site are important selectivity determinants.
Assuntos
Agonistas de Aminoácidos Excitatórios/síntese química , Receptores de Ácido Caínico/agonistas , Animais , Linhagem Celular , Cristalografia por Raios X , Desenho de Fármacos , Agonistas de Aminoácidos Excitatórios/química , Agonistas de Aminoácidos Excitatórios/farmacologia , Humanos , Modelos Moleculares , Propionatos/síntese química , Propionatos/química , Propionatos/farmacologia , Receptores de Ácido Caínico/química , Receptores de Ácido Caínico/fisiologia , Estereoisomerismo , Relação Estrutura-Atividade , Xenopus laevisRESUMO
We have constructed stable HEK293 cell lines expressing the rat ionotropic glutamate receptor subtypes GluR1(i), GluR2Q(i), GluR3(i), GluR4(i), GluR5Q and GluR6Q and characterised the pharmacological profiles of the six homomeric receptors in a fluorescence-based high throughput screening assay using Fluo-4/AM as a fluorescent Ca2+ indicator. In this assay, the pharmacological properties of nine standard GluR ligands correlated nicely with those previously observed in electrophysiology studies of GluRs expressed in Xenopus oocytes or mammalian cells. The potencies and efficacies displayed by the agonists (S)-glutamate, (S)-quisqualate, kainate, (RS)-AMPA, (RS)-ATPA, (RS)-ACPA] and (S)-4-AHCP at the six GluRs were in concordance with electrophysiological studies. Furthermore, the Ki values exhibited by the competitive antagonists NBQX and (RS)-ATPO were also in agreement with findings of previous studies. Finally, the effects of various concentrations of Ca2+ in the assay buffer and of the allosteric modulators cyclothiazide and concanavalin A on GluR signalling were examined. This study represents the most elaborate functional characterisation of multiple AMPA and KA receptor subtypes in the same assay reported to date. We propose that high throughput screening of compound libraries at the six GluR-HEK293 cell lines could be helpful in the search for structurally and pharmacologically novel ligands acting at the receptors.