RET and medullary thyroid gland carcinoma: At that time, selpercatinib was indicated for the treatment of metastatic RET fusion–positive NSCLC, advanced or metastatic RET-mutant MTC (in patients who require systemic therapy), and advanced or metastatic RET fusion–positive thyroid cancer (in patients who require systemic therapy and are radioactive iodine-refractory (if radioactive iodine is appropriate) [17].