Selpercatinib in Thyroid Cancer (Collaboration with the International Thyroid Oncology Group)

The study will enroll male and female patients between 12 and 40 years of age that have been diagnosed with RET fusion-positive radioiodine-refractory thyroid cancer.

As a participant in this research, you will:

• Receive a study drug called selpercatinib in combination with therapy you would receive as part of your regular cancer care (I-131 and thyrotropin alfa (rhTSH))
• Complete frequent clinic visits at CHOP
• Complete medication diaries
• Have blood tests performed as part of your regular cancer care
• Have tissue collected if you have a biopsy as part of your regular cancer care
• Have MRIs and X-rays if you are under the age of 18
• Have periodic imaging performed as part of your regular cancer care to evaluate your response to treatment
• Have periodic EKGs and echocardiograms as part of your regular cancer care