The FDA has granted afamelanotide (Scenesse, Clinuvel) for the prevention of phototoxicity in adults with erythropoietic protoporphyria (EPP).
Afamelanotide is a photo-protective alpha-melanocyte stimulating hormone—the synthetic form of a naturally-occurring peptide hormone released by skin cells in response to stimulation by ultraviolet radiation.
Implanted subcutaneously in short white rods, the hormone will cause the skin to produce eumelanin with the goal of increasing tolerance to sunlight in adults with a confirmed EPP diagnosis.
Prior to the FDA’s approval, the drug was granted both Priority Review and Orphan Drug designations.
The official approval stems from the results of two parallel group clinical trials, according to an FDA statement. In the first trial, 48 of 93 total subjects received afamelanotide (opposed to placebo) and were followed for a period of 180 days. Primary endpoint was measured as the number of hours over 180 days spent in direct sunlight between 10 a.m. and 6 p.m. without pain. The afamelanotide group reported a median number of 64 hours without pain over that period, compared to the 41 hours without pain in the placebo group.
In the second trial, 38 of 74 subjects received afamelanotide, were followed for 270 days, and reported the total number of hours spent in direct in sunlight in which “most of the day” was spent without pain. The afamelanotide group reported a median total of 6 hours, compared with 0.75 hours in the placebo group.
Afamelanotide is contraindicated in patients with a hypersensitivity to the active ingredient or excipients, severe hepatic disease, hepatic impairment, and renal impairment.
Adverse events reported with the use of afamelanotide include Nausea, headache, implant site reactions, oropharyngeal pain, cough, fatigue, skin hyperpigmentation, dizziness, non-acute porphyria, skin irritation.