KPT-185 is primarily used in biochemical and pharmacological research as a selective inhibitor of nuclear export proteins, particularly exportin 1 (XPO1/CRM1). It functions by covalently binding to the active site of XPO1, thereby blocking the nuclear export of tumor suppressor proteins and growth-regulating factors. This leads to the accumulation of these proteins in the nucleus, promoting cell cycle arrest and apoptosis in cancer cells.

Due to this mechanism, KPT-185 serves as a valuable tool compound in studies related to cancer biology, especially in evaluating the role of dysregulated nuclear transport in malignancies such as leukemia, multiple myeloma, and solid tumors. It is also used to validate XPO1 as a therapeutic target and to assess the potential of related compounds in preclinical drug development. Its application is mainly restricted to in vitro and early-stage in vivo research due to its experimental status and lack of clinical approval.