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ozureprubart   Click here for help

GtoPdb Ligand ID: 14334

Synonyms: JYB1904 | RPT-904 | RPT904
Immunopharmacology Ligand
Compound class: Antibody
Comment: Ozureprubart is a humanized IgG1κ monoclonal antibody against the constant region of the heavy chain of IgE (IGHE). It utilises the same epitope on the target protein as omalizumab and like its predecessor is designed to treat moderate to severe IgE-mediated immune reactions. Ozureprubart was originally developed by Jemincare Pharmaceutical (as JYB1904) and was licensed to Rapt Therapeutics (with code changed to RPT904) in 2025. Rapt was bought by GSK in early 2026. Based on available evidence we suspect that ozureprubart is antibody AB1904Am15 in [2] and patent WO2022007965A1 [1].
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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
Bioactivity Comments
Antibody AB1904Am15 binds potently to human IgE, blocks IgE interaction with FcεR1 and inhibits histamine release from FcεRI-expressing RBL-2H3 cells with an IC50 of 3.06 nM [2].
Selectivity at other protein targets
Key to terms and symbols Click column headers to sort
Target Sp. Type Action Value Parameter Concentration range (M) Reference
immunoglobulin heavy constant epsilon Hs Antibody Binding 8.5 pKd - 2
⤷ pKd 8.5 (Kd 3.15x10-9 M) [2]
Description: Binding affinity for IgE determined by SPR
immunoglobulin heavy constant epsilon Hs Antibody Binding 9.3 pIC50 - 2
⤷ pIC50 9.3 (IC50 5.3x10-10 M) [2]
Description: Antibody-mediated inhibition of IgE-FcεRI interaction determined by competitive ELISA