LAS41005 in Hyperkeratotic Actinic Keratosis

Main Inclusion Criteria:

• Signed and dated written informed consent.
• Men and women aged between 18 and 85 years inclusive.
• Have a general good and stable health condition as confirmed by a physical examination and by medical history.
• Have at least 4 but not more than 10 clinically confirmed hyperkeratotic AK target lesions of moderate to severe intensity within the face/forehead or bald scalp
• Skin type I to IV according to Fitzpatrick's .
• Are free of any significant physical abnormalities (e.g., tattoos, dermatoses) in the potential treatment area that may cause difficulty with examination or final evaluation.
• Physical ability to apply the study preparation correctly and to follow the study restrictions and visit.
• Women of childbearing potential are allowed to participate in this study, only if they use a highly effective method of contraception

Main Exclusion Criteria:

• Have received treatment of AK within the treatment area (face / scalp) in the three months preceding this clinical trial.
• Have known hypersensitivity to the ingredients
• Are subjects under immunosuppressive therapy.
• Having coagulation defects which are inherited or acquired
• Have evidence of clinically significant, unstable medical conditions
• Have currently other malignant or benign tumors of the skin within the treatment area
• Subjects who have taken topical or systemic treatments that might interfere with the study end points, within a time window that is not allowed, or who are currently taking phenytoin, methotrexate or sulfonylurea.
• Subjects taking inhibitors of DPD (e.g. Brivudin, Sorivudin)
• Are known to be pregnant or lactating (currently or within the past 3 months).
• Have any dermatological disease in the treatment area or surrounding area that may be exacerbated by treatment
• Are currently or within the past 8 weeks participating in another clinical study.
• Have active chemical dependency or alcoholism as assessed by the investigator.
• Subject is institutionalized because of legal or regulatory order.