Topical Sirolimus to Treat Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) causes the formation of hamartomatous tumors in multiple organs. Facial angiofibromas frequently arise during childhood and can be a source of patient distress owing to bleeding and effects on appearance. The standard treatment is surgical, delivered by multiple modalities, including lasers, shave excision, dermabrasion, electrosurgery, or cryosurgery. These approaches are effective but can create concerns about the potential for scarring, pain, anesthesia risk, postoperative recovery, and the need for repeated procedures delivered in the office or operating room. Consequently, there has been interest in the development of a topical therapy for home use that is painless and nonscarring. In this issue, Koenig and collaborators show that topical 0.1% or 1.0% sirolimus (rapamycin) applied once daily is safe and effective for treating facial angiofibromas. This is welcome news for many with TSC. Furthermore, these results are expected to fuel investigations into other uses for sirolimus in dermatology. The story of how topical sirolimus became a treatment option for TSC is based in scientific discoveries of its molecular target and that target's role in relevant diseases.