For people with erythropoietic protoporphyria (EPP), even brief sun exposure can trigger burning pain long before a rash appears. Afamelanotide was developed to extend the amount of light a person can tolerate before that reaction sets in.
Key Takeaways
- Afamelanotide is FDA-approved under the brand name SCENESSE for adults with EPP.
- It works as a melanocortin 1 receptor (MC1-R) agonist, based on its labeled indication.
- It is meant to increase pain-free light exposure, not to eliminate photosensitivity entirely.
- Across 23 registered trials, findings include a completed Phase 3 confirmatory study and a completed Phase 3 safety extension study.
- FAERS reports for afamelanotide are dominated by allergic-type reactions and implant site reactions.
What Afamelanotide Is
Afamelanotide is a synthetic peptide (PubChem CID 16197727) that acts on the melanocortin 1 receptor, the same receptor pathway involved in skin pigmentation. By activating MC1-R, it is intended to help the skin build tolerance to light before painful phototoxic reactions occur.
What Afamelanotide Is Approved For
Under the brand name SCENESSE, afamelanotide is indicated to increase pain-free light exposure in adults with a history of phototoxic reactions from erythropoietic protoporphyria. It is not framed as a cure for EPP but as a way to extend the window of tolerable sun exposure.
What The Evidence Shows
Afamelanotide has been studied across 23 registered clinical trials. A completed Phase 3 confirmatory study evaluated its use in erythropoietic protoporphyria, and a separate completed Phase 3 safety extension study followed EPP patients over additional time. A Phase 2 trial has also explored afamelanotide in xeroderma pigmentosum types C and V, though its status is not listed as complete.
Reported Side Effects
FAERS data reflect voluntary safety reports, not confirmed rates or proof that afamelanotide caused the event. The most frequently reported issues involve hypersensitivity: anaphylactic reaction (4 reports), type I hypersensitivity (3), and reactions at the implant site including hypersensitivity, pruritus, and urticaria (2 reports each). Vomiting (2 reports) and a single report of acute kidney injury were also recorded.