Selpercatinib (RETEVMO™) is a receptor tyrosine kinase RET (rearranged during transfection) inhibitor being developed by Loxo Oncology for the treatment of cancers harbouring RET alterations. Based on results from the phase I/II LIBRETTO-001 trial, selpercatinib was recently approved by the US FDA for the treatment of RET fusion-positive non-small-cell lung cancer, RET fusion-positive thyroid cancer and RET-mutant medullary thyroid cancer. This article summarizes the milestones in the development of selpercatinib leading to this first approval.