Extending IGF-1 Receptor Inhibition Beyond Thyroid Eye Disease: A Scoping Review of Teprotumumab Administration in Pretibial Myxedema.

Background: Pretibial myxedema is an infrequent dermatologic manifestation of autoimmune thyroid disease characterized by glycosaminoglycan deposition within the dermis. Treatment options are limited, lacking durable effect and remain largely palliative. Emerging evidence, however, suggests pretibial myxedema may share a common pathophysiology with thyroid eye disease, raising the possibility that inhibition of the insulin-like growth factor-1 receptor may offer therapeutic benefit. Methods: With the scant literature documenting a response (or lack thereof) to teprotumumab therapy for pretibial myxedema, our objective is to thematically analyze and review the existing literature pertaining to this lesser-known phenomenon, with particular emphasis on clinical response and durability. A scoping review was performed with a search of 3 databases between January 2020 and 2026. Eligible studies included patients with pretibial myxedema with exposure to teprotumumab. Data extraction included study characteristics, patient demographics, treatment regimens, time to clinical improvement, relapse patterns, and follow-up duration. Results: Overall, Conclusions: Teprotumumab demonstrated improvement in pretibial myxedema, supporting the notion of a shared pathophysiologic basis with thyroid eye disease. Prospective registries and standardized outcome measures are needed to define durability, retreatment strategies, and long-term safety.