In May 2020, the FDA granted Accelerated Approval to the RET kinase inhibitor selpercatinib for patients with metastatic non-small-cell lung cancer (NSCLC) harbouring RET fusions and for those with metastatic medullary thyroid cancer (MTC) harbouring RET mutations. In September 2022, the approval of selpercatinib for NSCLC was converted into a regular approval. These regulatory decisions were all based on results from a phase I/II trial. Now, data from two phase III trials support the efficacy of selpercatinib.