XPC-6444 is a highly potent, isoform-selective, and CNS-penetrant NaV1.6 inhibitor (IC50=41 nM for hNaV1.6). XPC-6444 also displays potent block of NaV1.2 (IC50=125 nM). XPC-6444 shows anticonvulsant activity.IC50 & Target: IC50: 41 nM (hNaV1.6), 125 nM (hNaV1.2)In Vitro: XPC-6444 shows high selectivity over NaV1.1 and NaV1.5.In Vivo: XPC-6444 exhibits good metabolic stability in human liver microsomes and hepatocytes, and low potential for MDR1 mediated efflux.