Histamine H₃ receptor antagonists/inverse agonists: a patent review (October 2017 – December 2023) documenting progress

Histamine H₃ receptor antagonists/inverse agonists, since the discovery of histamine H₃ receptor (H₃R), are important ligands in the search for new potential drugs. The most interesting are CNS diseases as these receptors are mainly there present. The current review covers patent applications/patents that were published during the last 6 years (October 2017 – December 2023). Documents were found in two free available patent databases: Espacenet and PatentScope and divided into three basic categories such as methods, compounds, and therapeutic indications. It provides an overview of 51 patent applications/patents. Many pharmaceutical compositions with H₃R antagonists/inverse agonists have been claimed. Furthermore, PubMed, Scopus, and ClinicalTrials databases were searched for literature to prepare this review. Interest in the H₃R field is still high and has remained almost unchanged over the last 10 years in the number of publications, but the type of publications has changed (fewer new ligands, more pharmacological studies). Currently, the search for new H₃R ligands is focused on multi-target compounds. The first crystal structure of H₃R with a ligand appeared. New therapeutic indications, such as autism, fatigue, and Prader-Willi syndrome, are verified in clinical trials.