ASP-9521 is primarily investigated for its potential therapeutic application in the treatment of neurological disorders, particularly epilepsy and neuropathic pain. It functions as a selective inhibitor of specific voltage-gated sodium channels involved in neuronal hyperexcitability. By modulating abnormal electrical activity in the nervous system, ASP-9521 helps reduce seizure frequency and alleviate chronic pain signals. Its targeted mechanism offers potential advantages over older anticonvulsants, including fewer cognitive side effects and improved tolerability. Research has focused on its use in drug-resistant epilepsy, where conventional treatments fail to provide adequate control. Though still in experimental stages, ASP-9521 represents a promising candidate for next-generation neurotherapeutics with a refined safety and efficacy profile.