Ingenol Mebutate 0.015% Gel in the Treatment of Actinic Keratoses (AK) on the Face and Scalp

Study Summary

Actinic keratoses (AK) are common cutaneous lesions associate with chronic ultraviolet radiation exposure. While most authorities consider AK as a pre-malignant lesion, some consider it as an incipient squamous cell carcinoma (SCC). Among the current therapies for the treatment of AK are excisional surgery, cryosurgery, electrodesiccation and curettage, topical chemotherapy and light therapies. Cryosurgery is considered the gold standard for therapy, however as with other lesion-directed therapies, cryosurgery does not treat subclinical lesions in the surrounding skin. Ingenol mebutate is the active compound in the sap from Euphorbia peplus L. (E. peplus). Topical ingenol mebutate treatment has been approved for the treatment of AKs. The goal of AK therapy for all physicians is to provide an effective, tissue-sparing treatment with good cosmetic results. Ingenol mebutate gel 0.015% has shown to not only have a high clearance rate but also a transient localized inflammatory skin response that resolves quickly without sequelae. However, one common fear about ingenol mebutate is that it's mechanism of action is purely destructive to both AKs and healthy skin, and that retreatment would produce an equally, if not more, caustic result on the skin such as severe erosion, scaling, and erythema. It is our hope to debunk this misconception and demonstrate that reapplication of a second cycle of ingenol mebutate would result in lower LSR scores compared to the LSR in the first cycle of application. We plan to treat 20 subjects. Each qualifying subject will have at least 4-8 non-hypertrophic AKs in a 25 cm2 treatment area on the face or scalp. All subjects will be treated with two cycles of ingenol mebutate 0.015%. The first cycle will be started on Day 1, and the second cycle will be started on Day 29 (four weeks apart). Subjects will utilize the once daily for three days regimen for both cycles.

Primary Outcome

To evaluate the degree of irritation, as measured by local skin reactions (LSR), after a second cycle of ingenol mebutate gel to the face or scalp through photography assessed by a blinded observer.

Interventions

• DRUG Ingenol Mebutate 0.015%