Emerging Therapies for Radioactive Iodine Refractory Thyroid Cancer

The landscape of treatment options for radioactive iodine refractory thyroid cancer is rapidly changing. While there are no curative options in this setting, tyrosine kinase inhibitors (TKIs) have revolutionized the management of radioiodine refractory disease to help delay progression of metastatic and life-threatening disease. Ongoing development of more selective targeted inhibitors will certainly improve medication tolerability and tumor specificity. In this review, we discuss the epidemiology of radioactive iodine refractory thyroid cancer and examine the definition of radioactive iodine refractory disease and the current systemic therapy options. We then discuss molecularly targeted strategies both approved by the FDA and currently under study in clinical trials. In particular, we examine the data relevant to specific targeted mutations in thyroid cancer. We also discuss novel approaches in development, such as immunotherapy, to the management of radioactive iodine refractory disease.