Karyopharm Therapeutics

Karyopharm Therapeutics, based in Newton, Massachusetts, and listed as KPTI, makes selinexor, sold as Xpovio, the first nuclear export inhibitor, approved in multiple myeloma and diffuse large B-cell lymphoma. Its bet on endometrial cancer failed in 2026 when the phase 3 XPORT-EC-042 trial of maintenance selinexor in TP53-wild-type disease missed its primary endpoint in July, after which the company refocused on myelofibrosis and myeloma. OnCo links it to endometrial cancer, to the XPORT-EC-042 trial record and to selinexor. Whether a biomarker-selected maintenance strategy failed because of the drug or because of the TP53 hypothesis is the question the trial leaves open. Selinexor has its own page.