Sirolimus: a therapeutic advance for dermatologic disease

Sirolimus, also known as rapamycin (SRL, Rapamune®), was approved in 1999 by the US Food and Drug Administration to prevent graft rejection in renal transplantation. As a member of the mammalian target of rapamycin (mTOR) inhibitor class, its potent immunosuppressant, anti-angiogenic and anti-proliferative properties are well recognized. When compared to other immunosuppressants, SRL has a lower risk of renal, neurologic and lymphoproliferative complications. It has become a promising treatment modality for angiofibromas, Kaposi's sarcoma and other inflammatory and malignant disorders of the skin. With the recent discovery that mTOR inhibitors extend the lifespan of mice, sirolimus and other rapamycin analogs (rapalogs) are emerging as therapeutic targets for the treatment and prevention of age-related diseases.