This study is designed to follow up patients who have achieved complete clearance of AK lesions at the Day 57 visit having completed the PEP005-016 or PEP005-025 studies over a 12 month period to assess both recurrence of Actinic Keratosis (AK) lesions and long term safety in the selected treatment area.

A 12 month long-term follow-up study of patients who have achieved complete clearance of AK lesions at the Day 57 in the Phase 3 studies PEP005-016 or PEP005-025.

Inclusion Criteria:

• Patient must have achieved complete clearance of AK lesions (lesion count = 0) at Day 57 in one of the following Peplin AK clinical studies: PEP005-016 or PEP005-025
• Patient has provided informed consent documented by signing the Informed Consent Form (ICF) prior to any study-related procedures

Exclusion Criteria:

• Concurrent participation in another research study which would involve the selected treatment area (except for any post-study follow-up visits for previous Peplin AK study)
• Early termination from study PEP005-016 or PEP005-025

All patients must have achieved complete clearance of AK lesions at Day 57 visit in either study PEP005-016 or PEP005-025 will be offered participation in this study.