Follicular Thyroid Cancer

Participants in this study will be patients diagnosed with or suspected to have a thyroid nodule or thyroid cancer. The main purpose of this study is to further understand the methods for the diagnosis and treatment of thyroid nodules and thyroid cancer. Many of the test performed are in the context of standard medical care that is offered to all patients with thyroid nodules or thyroid cancer. Other tests are performed for research purposes. In addition, blood and tissue samples will be taken for research and genetic studies.

This research is being done to determine the efficacy of selpercatinib to restore radioactive iodine (I-131 NaI) uptake and allow for I-131 treatment in people with RET fusion-positive radioiodine-refractory thyroid cancer. This research study involves the study drug selpercatinib in combination with standard of care treatments, I-131 and thyrotropin alfa (rhTSH).