Selpercatinib plus cemiplimab in RET positive medullary thyroid cancer patient with skin cancers

Background: Remarkable advancements in the therapeutic armamentarium for medullary thyroid cancer (MTC) have been observed in the last 10 years. The current understanding of driver mutations, such as RET and RAS, has enabled the development of new therapies for advanced and metastatic disease, demonstrating improved efficacy. Patient Findings: A patient with RET-positive hereditary MTC developed multiple skin cancers (basal cell and squamous cell carcinomas) along with progression of MTC after 12 years of treatment with vandetanib. Once surgery to manage skin cancers has been excluded, the patient received a combination of selpercatinib and cemiplimab, and has been on this treatment at the full dose for 15 months, with ongoing therapy. Summary: The combination of selpercatinib and cemiplimab was possible, with no new safety signals observed.