gefapixant   Click here for help

GtoPdb Ligand ID: 9540

Synonyms: AF-219 | AF219 | Lyfnua® | MK7264 | MK‐7264
Approved drug PDB Ligand Immunopharmacology Ligand
gefapixant is an approved drug (Japan (2022))
Compound class: Synthetic organic
Comment: Gefapixant (MK‐7264, and formerly AF-219) is a P2X3 and P2X2/3 receptor antagonist. Experimental results have shown that gefapixant acts as a reversible allosteric antagonist, that exhibits preferential activity at closed channels.
Studies in rodent models have provided evidence that supports investigation of gefapixant as a novel treatment for chronic sensitisation conditions [7].
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Ligand Activity Visualisation Charts

These are box plot that provide a unique visualisation, summarising all the activity data for a ligand taken from ChEMBL and GtoPdb across multiple targets and species. Click on a plot to see the median, interquartile range, low and high data points. A value of zero indicates that no data are available. A separate chart is created for each target, and where possible the algorithm tries to merge ChEMBL and GtoPdb targets by matching them on name and UniProt accession, for each available species. However, please note that inconsistency in naming of targets may lead to data for the same target being reported across multiple charts.

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View interactive charts of activity data across species
2D Structure
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2D Structure

An image of the ligand's 2D structure. For small molecules with SMILES these are drawn using the NCI/CADD Chemical Identifier Resolver. Click on the image to access the chemical structure search tool with the ligand pre-loaded in the structure editor. For other types of ligands, e.g. longer nucleotides and peptides, a manually drawn representation of the molecule may be provided.

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Physico-chemical Properties
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Physico-chemical Properties

Calculated molecular properties are available for small molecules and natural products (not peptides). Properties were generated using the CDK toolkit. All properties were selected to enable the prediction of the Lipinski Rule-of-Five profile or ‘druglikeness’ for each ligand. For more info on each category see the help pages.

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Hydrogen bond acceptors 7
Hydrogen bond donors 3
Rotatable bonds 5
Topological polar surface area 164.82
Molecular weight 353.12
XLogP 0.6
No. Lipinski's rules broken 0
SMILES / InChI / InChIKey
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SMILES / InChI / InChIKey

SMILES (Simplified Molecular Input Line Entry Specification) A specification for unambiguously describing the structure of chemical molecules using short ASCII strings. Canonical SMILES specify a unique representation of the 2D structure without chiral or isotopic specifications. Isomeric SMILES include chiral specification and isotopes.

Standard InChI (IUPAC International Chemical Identifier) and InChIKey InChI is a non-proprietary, standard, textual identifier for chemical substances designed to facilitate linking of information and database searching. An InChIKey is a simplified version of a full InChI, designed for easier web searching.

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Canonical SMILES COc1cc(C(C)C)c(cc1S(=O)(=O)N)Oc1cnc(nc1N)N
Isomeric SMILES COc1cc(C(C)C)c(cc1S(=O)(=O)N)Oc1cnc(nc1N)N
InChI InChI=1S/C14H19N5O4S/c1-7(2)8-4-10(22-3)12(24(17,20)21)5-9(8)23-11-6-18-14(16)19-13(11)15/h4-7H,1-3H3,(H2,17,20,21)(H4,15,16,18,19)
InChI Key HLWURFKMDLAKOD-UHFFFAOYSA-N
No information available.
Summary of Clinical Use Click here for help
Gefapixant is being evaluated in clinical trials for indications that are underscored by chronic sensitisation. The most advanced trials are ongoing in patients with chronic refractory/idiopathic cough. A trial in patients with virally-induced acute cough (NCT03569033) was terminated as it was unlikely to meet its study endpoints upon assessment of interim efficacy data. Click here to link to ClinicalTrials.gov's full list of gefapixant trials.
The following references highlight the clinical potential of ATP antagonism in human diseases: [2,6]. First approval was granted in Japan in 2022, for the treatment of refractory or unexplained chronic cough [4].
Clinical Trials
Clinical Trial ID Title Type Source Comment References
NCT01432730 A Study to Assess the Efficacy of Gefapixant (MK-7264/AF-219), in Participants With Chronic Cough (MK-7264-006) Phase 2 Interventional Afferent Pharmaceuticals, Inc. Gefapixant (AF-219) reduces the P2X3 receptor-induced hypersensitisation of airway sensory neurons that can underly chronic cough, and exhibits antitussive efficacy in human trial subjects with refractory chronic cough. 1
NCT02349425 A Dose Escalation Study of Gefapixant (AF-219/MK-7264) in Refractory Chronic Cough Phase 2 Interventional Afferent Pharmaceuticals, Inc. This dose escalation study showed that gefapixant's antitussive efficacy was maintained at lower doses than has been determined previously, and that the lower effective dose improved tolerability. 8
NCT03449147 A Study of Gefapixant (MK-7264) in Adult Participants With Chronic Cough (MK-7264-030) Phase 3 Interventional Merck Sharp & Dohme Corp. The COUGH-2 phase 3 study 5
NCT03449134 A Study of Gefapixant (MK-7264) in Adult Participants With Chronic Cough (MK-7264-027) Phase 3 Interventional Merck Sharp & Dohme LLC The COUGH-1 phase 3 study 5