How Afamelanotide Reduces Phototoxic Episodes in Patients With EPP

In this Dermatology Times Expert Perspectives video series episode, Elizabeth Buzney, MD, a dermatologist at Brigham and Women's Hospital and part of Mass General Brigham Dermatology in Boston, Massachusetts, outlined the key clinical considerations for afamelanotide in patients with erythropoietic protoporphyria (EPP), including how the implant works, how it is placed, and what the long-term safety data show.

Mechanism of Action and Administration

Afamelanotide is delivered as a solid, controlled-release subcutaneous implant, approximately 1.5 centimeters in length and 1.5 to 2 millimeters in diameter. It is a synthetic analog of alpha-melanocyte stimulating hormone that stimulates melanin production, specifically eumelanin, to increase photoprotection and enhance the skin's resistance to light-induced oxidative stress. Buzney described the implant as placed into the subcutaneous tissue of the hips or love handle area in the office, administered no more frequently than every eight weeks.

"It results in longer pain-free intervals, increased light tolerance, fewer phototoxic episodes, and improved quality of life," Buzney said.

Safety Profile and Tolerability

According to Buzney, afamelanotide has been administered in approximately 21,000 doses to EPP patients over roughly 3 decades, with consistent safety data across the treatment history. Adverse events are generally mild and transient. Buzney noted reported events include nausea, headache, implant site reactions, hyperpigmentation, and rarely infection at the implantation site.

"There's been no signal for systemic toxicity or serious adverse trends with repeated use, and there's been long-term data support showing sustained safety across multiple treatment cycles," Buzney said.

She characterized the overall tolerability as strong, noting adverse events are infrequent in her clinical experience.