Karyopharm Therapeutics Inc...today announced new regulatory designations for eltanexor, a novel oral, Selective Inhibitor of Nuclear Export (SINE) investigational compound being studied for the treatment of myelodysplastic syndromes (MDS): (i) the U.S. Food and Drug Administration (FDA) has granted fast track designation for the development program of eltanexor as monotherapy for the treatment of patients with relapsed or refractory intermediate, high-, or very high-risk MDS; (ii) the European Commission (EC) adopted the Committee for Orphan Medicinal Products (COMP) opinion to designate eltanexor as an orphan medicinal product for the treatment of MDS in the European Union (EU).