RESUMO
1. Ponesimod is a selective modulator of the sphingosine 1-phosphate receptor 1 (S1P1) approved for the treatment of active relapsing forms of multiple sclerosis. The chemical structure of ponesimod contains a glycerol side chain which is the major target of drug metabolism in humans.2. The two major metabolic pathways give the acids M12 (-OCH2CH(OH)COOH) and M13 (-OCH2COOH). While the former results from oxidation of the terminal alcohol, the mechanism yielding the chain-shortened acid M13 is less obvious. A detailed mechanistic study with human liver microsomes and hepatocytes using ponesimod, M12 and some of the suspected intermediates revealed an unexpectedly complex pattern of enzyme-mediated and chemical reactions.3. Metabolic pathways for both acids were not independent and several of the transformations were reversible, depending on reaction conditions. Formation of M13 occurred either via initial oxidation of the secondary alcohol, or as a downstream process starting from M12.4. The phenol metabolite M32 was produced as part of several pathways. Control experiments at various pH values and in the absence of metabolising enzymes support the conclusion that its formation resulted from chemical degradation rather than from metabolic processes.
Assuntos
Microssomos Hepáticos , Oxirredução , Humanos , Microssomos Hepáticos/metabolismo , Glicerol/metabolismo , Tiazóis/metabolismo , Hepatócitos/metabolismo , Moduladores do Receptor de Esfingosina 1 Fosfato/metabolismoRESUMO
Lysophosphatidic acid receptor 1 (LPAR1) antagonists show promise as potentially novel antifibrotic treatments. In a human LPAR1 ß-arrestin recruitment-based high-throughput screening campaign, we identified urea 19 as a hit with a LPAR1 IC50 value of 5.0 µM. Hit-to-lead activities revealed that one of the urea nitrogen atoms can be replaced by carbon and establish the corresponding phenylacetic amide as a lead structure for further optimization. Medicinal chemistry efforts led to the discovery of piperidine 18 as a potent and selective LPAR1 antagonist with oral activity in a mouse model of LPA-induced skin vascular leakage. The molecular scaffold of 18 shares no obvious structural similarity with any other LPAR1 antagonist disclosed so far.
Assuntos
Amidas , Receptores de Ácidos Lisofosfatídicos , Camundongos , Animais , Humanos , Modelos Animais de Doenças , UreiaRESUMO
Piperidine 3 is a potent and selective lysophosphatidic acid receptor subtype 1 receptor (LPAR1) antagonist that has shown efficacy in a skin vascular leakage target engagement model in mice. However, compound 3 has very high human plasma protein binding and high clearance in rats, which could significantly hamper its clinical development. Continued lead optimization led to the potent, less protein bound, metabolically stable, and orally active azetidine 17. Rat pharmacokinetics (PK) studies revealed that 17 accumulated in the liver. In vitro studies indicated that 17 is an organic anion co-transporting polypeptide 1B1 (OATP1B1) substrate. Although analogue 24 was no longer a substrate of OATP1B1, PK studies suggested that the compound undergoes enterohepatic recirculation. Replacing the carboxylic acidic side chain by a non-acidic sulfamide moiety and further fine-tuning of the scaffold yielded the potent, orally active LPAR1 antagonist 49, which was selected for preclinical development for the treatment of fibrotic diseases.