In the phase 1/2 LIBRETTO-001 trial, selpercatinib exhibited durable efficacy with mostly low-grade adverse effects in patients with RET-altered thyroid cancer, including RET-mutant medullary thyroid cancer and RET fusion-positive thyroid cancer.511 The response rate and PFS were drastically high in all groups of patients, regardless of previous vandetanib or cabozantinib treatment. This evidence concerns the gene RET and thyroid cancer.