Karyopharm Therapeutics Inc., a clinical-stage pharmaceutical company, focuses on the discovery and development of drugs directed against nuclear transport targets for the treatment of cancer and other major diseases. The company's lead drug candidate includes Selinexor, an oral selective inhibitors of nuclear export (SINE) compound that specifically blocks XPO1 cargo binding is in Phase I clinical trials in patients with heavily pretreated relapsed and/or refractory hematological and solid tumor malignancies. Its other drug candidates comprise KPT-350 and related SINE compounds; PAK4 inhibitors; and Verdinexor, a SINE compound that is in Phase IIb clinical trials in pet dogs with newly-diagnosed or first relapse after chemotherapy lymphomas. The company was founded in 2008 and is based in Natick, Massachusetts.