The purpose of this study is to determine whether the afamelanotide (CUV1647) formulation is effective in preventing PLE episodes or reducing the severity of PLE symptoms in patients with a well documented history of the disease. The study also aims to determine whether treatment with afamelanotide (CUV1647) can reduce the use of rescue medication in this group.

Polymorphic Light Eruption (PLE) is a prevalent photosensitivity disorder, occurring in up to 20% of the European and US populations and up to 5% of the Australian population. The disease is characterised by a rash that is intensely itchy with blisters, bumps and patches presenting on areas of the skin that have been exposed to the sun. There is a lack of effective treatment available for the condition but the most common available forms of therapy include sun avoidance and the use of the use of steroids and/or phototherapy.

Inclusion Criteria:

• Aged 18 - 70 years at inclusion.
• Well documented history of moderate/severe PLE as diagnosed/confirmed by a photodermatologist or photobiologist. Newly diagnosed patients with moderate/severe PLE can be included if numbers of established patients are limited provided their diagnosis is confirmed by a photodermatologist or photobiologist.
• Recurrent episodes that occur at least once a year, developing in own country (to exclude patients affected only when traveling to sunnier climates).
• Have given written informed consent to participate in the study.

Exclusion Criteria:

• Personal history of melanoma, lentigo maligna or multiple (3 or more) dysplastic nevi.
• Current Bowen's Disease, basal cell carcinoma, squamous cell carcinoma or other malignant skin lesions.
• Documented history of other photosensitive conditions.
• Female who is pregnant (confirmed by positive serum β-HCG pregnancy test prior to baseline) or lactating.
• Females of child-bearing potential that are not using adequate contraceptive measures.

Patients with moderate/severe polymorphic light eruption (PLE)