Seclidemstat (mesylate) is an investigational small molecule inhibitor targeting lysine-specific demethylase 1 (LSD1), an enzyme involved in epigenetic regulation of gene expression. Its primary application is in oncology, particularly in the treatment of advanced or metastatic cancers where LSD1 plays a role in tumor progression. It has shown potential in clinical trials for Ewing sarcoma and other solid tumors by reactivating silenced tumor suppressor genes and promoting differentiation of cancer cells. Additionally, seclidemstat is being explored for use in hematologic malignancies due to LSD1’s role in blocking normal blood cell differentiation. The compound’s ability to modulate the epigenetic landscape makes it a candidate for combination therapies with other anticancer agents such as immune checkpoint inhibitors or chemotherapy.