Afamelanotide for treating erythropoietic protoporphyria

2 The condition

2.1 Erythropoietic protoporphyria (EPP) is a genetic disorder. It is caused by impaired activity of the enzyme, ferrochelatase. The condition results in excessive amounts of protoporphyrin IX in the skin, bone marrow, blood plasma and red blood cells. EPP is a cutaneous porphyria, and the major symptom is phototoxicity (a chemical reaction underneath the skin) caused by sunlight and some types of artificial light. The skin can rapidly become severely painful, swollen, itchy and red, and skin erosions can also occur. A phototoxic reaction typically lasts between 2 days and 3 days. However, it can last 10 or more days, with severe pain and loss of sleep. These symptoms, along with anxiety and social isolation because of sunlight avoidance, can have a profound effect on quality of life. Over time, light exposure can cause thickening of the skin on the knuckles and scarring on the face. A small proportion of people with EPP may have important complications related to liver and gallbladder function.