Study to Evaluate the Safety of BF-200 ALA (Ameluz®) for Photodynamic Therapy (PDT) in the Treatment of Expanded Fields of Actinic Keratosis (AK)

Inclusion Criteria

• Subjects with at least 12 distinctive and clinically confirmed mild to severe AK lesions (according to Olsen et al. 1991 (37)) with a diameter of ≥ 4 mm each, on either the face/scalp (including forehead, excluding eyes, nostrils, ears, and mouth) or the neck/trunk/extremities, within treatment field(s) of about 60 cm² in total. Treatment field(s) may be discontinuous but must be within 2 illumination areas of the BF-RhodoLED® lamp (6 cm x 16 cm each).
• All genders 18-85 years of age (inclusive).
• Willingness and ability of the subject to provide informed consent and to sign the Health Insurance Portability and Accountability Act (HIPAA) form. A study-specific informed consent form and HIPAA form must be obtained in writing for all subjects prior to starting any study procedures.
• Willingness and ability to comply with study procedures, particularly willingness to receive one PDT with up to two illumination devices simultaneously.
• Subjects with good general health and subjects with clinically stable medical conditions will be permitted to be included in the study.
• Subjects receiving any drugs affecting coagulation (e.g. anticoagulants, anti-platelet drugs) should be on a stable dose.
• Acceptance to abstain from extensive sunbathing and the use of solarium during the clinical study.
• Women of child-bearing potential must have a negative serum pregnancy test and must use an adequate and highly effective or two effective methods of contraception throughout the study.

Exclusion Criteria

• Any known history of hypersensitivity to ALA, porphyrins or excipients of BF- 200 ALA.
• History of soy or peanut allergy.
• Subjects with sunburn within illumination areas (reassessment of subjects is allowed once if the sunburn is expected to resolve within the screening period. Reassessment can be done on the day of the actual treatment.).
• Clinically significant medical conditions making implementation of the protocol or interpretation of the study results difficult or impairing subjects' safety such as:
• Presence of porphyria or known photodermatoses
• Known diagnosis of human immunodeficiency virus (HIV) based on clinical history
• Metastatic tumor or tumor with high probability of metastasis
• Infiltrating skin neoplasia (suspected or known)
• Unstable cardiovascular disease (New York Heart Association [NYHA] class III, IV)
• Unstable hematologic (including Myelodysplastic syndrome), hepatic, renal, neurologic, or endocrine condition
• Unstable collagen-vascular condition
• Unstable gastrointestinal condition
• Immunosuppressive condition
• Presence of clinically significant inherited or acquired coagulation defect
• Clinical diagnosis of atopic dermatitis, Bowen's disease, BCC, eczema, psoriasis, rosacea, SCC, other malignant or benign tumors in the treatment field(s), or other possible confounding skin conditions (e.g. wounds, irritations, bleeding or skin infections) within or in close proximity ( 10 cigarettes/day or equivalent).
• Suspicion of drug or alcohol abuse. For the purpose of this study, alcohol abuse is defined as more than moderate alcohol consumption (> 1 drink/day for women and > 2 drinks/day for men).
• Physical treatment of malignant or benign tumors of the skin within the treatment field(s) and at a distance of < 5 cm to the treatment field(s) during the last 4 weeks prior to screening.
• Any therapy such as cryotherapy, laser therapy, electrodessication, surgical removal of lesions, curettage, or treatment with chemical peels such as trichloroacetic acid within the treatment field(s), or within a radius less than 5 cm away from the treatment field(s) 4 weeks prior to screening.
• Any topical medical treatment of the skin within the designated time period below:
• Topical treatment with ALA or methyl-aminolevulinate (MAL) or an investigational drug in- and outside the treatment field(s) within 8 weeks prior to screening.
• Topical treatment with imm