Selinexor (XPOVIO™) is a first-in-class, oral, small molecule Exportin-1 (XPO1) inhibitor that is being developed by Karyopharm Therapeutics for the treatment of cancer. Selinexor (in combination with dexamethasone) received accelerated approval in the USA in July 2019 for the treatment of adult patients with relapsed or refractory multiple myeloma (RRMM). Selinexor is also undergoing clinical development in a wide range of haematological and solid cancers. This article summarizes the milestones in the development of selinexor leading to this first approval for RRMM.