The FDA approved the first treatment, afamelanotide (Scenesse), for rare phototoxic disorder erythropoietic protoporphyria.
Afemelanotide, an melanocortin-1 receptor agonist, is indicated to increase pain-free light exposure for adults with a history of phototoxic reactions from the disorder.
Photosensitivity from the disorder usually manifests in early childhood, with severe burning neurologic pain that can last for days after exposure to direct sunlight. Swelling and redness often come along with these reactions, which typically drives patients to avoid sun exposure and live largely at night.
“Prior to today’s approval, there were no FDA-approved treatments to help erythropoietic protoporphyria patients increase their light exposure,” noted Julie Beitz, MD, director of FDA’s Center for Drug Evaluation and Research Office of Drug Evaluation III, in a statement.
Treatments like beta carotene, N-acetyl-L-cysteine, and vitamin C have been used but with little or no benefit, according to a systematic review.
Approval was based on two parallel randomized clinical trials in which patients got the drug or placebo implanted every 2 months.
In the U.S. trial, the pain-free time spent in direct sun was substantially longer with the drug (median 64 vs 40 hours over 180 days). In the European trial, pain-free time outside during peak sun exposure hours was also significantly longer with afamelanotide (median 6.0 vs 0.75 hours over 9 months).
The EU trial showed phototoxic reactions roughly halved compared with placebo, the U.S. trial showed no significant difference. Both trials showed improved quality of life.
A subcutaneous implant of afemelanotide increases production of photo-protective eumelanin in the skin independent of exposure to sunlight or artificial light sources. Because of this, it can induce skin darkening, so full body skin examination is recommended twice a year during use.
The treatment also doesn’t eliminate the need for sun protection measures.
The most common adverse events are implant site reaction, nausea, oropharyngeal pain, cough, fatigue, skin hyperpigmentation, dizziness, and moles.