Neoadjuvant selpercatinib for advanced medullary thyroid cancer

Abstract

Background: Targeted kinase inhibitors have been increasingly utilized in the treatment of advanced medullary thyroid cancer (MTC) over the last decade. Recently, highly potent next generation selective RET inhibitors have been clinically validated, and selpercatinib was recently Food and Drug Administration (FDA)-approved for advanced MTC. The advent of highly selective, potent RET inhibitors is broadening the treatment options for patients with RET-mutated cancers. Methods: We report the first published case of neoadjuvant selpercatinib followed by surgery for a patient with initially unresectable, widely metastatic, RET-mutated MTC who was treated on a single patient protocol. Results: After greater than 50% RECIST response, the patient underwent complete surgical resection followed by selpercatinib resumption. He remains locoregionally disease-free 21 months after starting therapy with stable metastatic disease (after initial partial response); and calcitonin/CEA continue to decline. Conclusion: This novel treatment strategy for locoregionally advanced RET-mutated MTC warrants further study in clinical trials.