S-1517

S-1517 (also identified by the study code QSC301642) is an investigational small molecule developed by Shionogi for the treatment of pain. It functions as a P2X purinoceptor 3 (P2X3) antagonist, targeting ATP-gated ion channels that play a critical role in the sensitization of primary sensory neurons and the transmission of pain signals. By blocking P2X3 receptors, S-1517 is intended to alleviate chronic and neuropathic pain conditions. The drug has been evaluated in Phase I clinical trials in the United Kingdom, conducted in collaboration with Quotient Sciences, focusing on safety, tolerability, and pharmacokinetics in healthy volunteers. While detailed study information was initially deferred by the sponsor in public registries, the asset is part of Shionogi's broader pipeline targeting purinergic signaling for neurological and sensory disorders.