A new, objective, quantitative scale for measuring local skin responses following topical actinic keratosis therapy with ingenol mebutate.

INTRODUCTION: Local skin responses (LSRs) are the most common adverse effects of topical actinic keratosis (AK) therapy. There is currently no method available that allows objective characterization of LSRs. Here, the authors describe a new scale developed to quantitatively and objectively assess the six most common LSRs resulting from topical AK therapy with ingenol mebutate. METHODS: The LSR grading scale was developed using a 0-4 numerical rating, with clinical descriptors and representative photographic images for each rating. Good inter-observer grading concordance was demonstrated in peer review during development of the tool. Data on the use of the scale are described from four phase III double-blind studies of ingenol mebutate (n = 1,005). RESULTS: LSRs peaked on days 4 (face/scalp) or 8 (trunk/extremities), with mean maximum composite LSR scores of 9.1 and 6.8, respectively, and a rapid return toward baseline by day 15 in most cases. Mean composite LSR score at day 57 was generally lower than at baseline. CONCLUSION: The LSR grading scale is an objective tool allowing practicing dermatologists to characterize and compare LSRs to existing and, potentially, future AK therapies.

Tolerability and Pharmacokinetics of Ingenol Mebutate 0.05% Gel Applied to Treatment Areas up to 100cm(2) on the Forearm(s) of Patients with Actinic Keratosis.

OBJECTIVE: To determine safety, tolerability, and systemic absorption of ingenol mebutate 0.05% gel applied for two consecutive days to treatment areas up to 100cm(2) on the forearm(s) of patients with actinic keratosis. DESIGN AND SETTING: Two studies are reported: a Phase 1, multicenter, open-label, dose-area escalation cohort study (http://www.clinicaltrials.gov/ct2/show/NCT00659893) and a Phase 2, double-blind, vehicle-controlled pharmacokinetic study (http://clinical trials.gov/ct2/show/NCT00852137). PARTICIPANTS: The Phase 1 study included male patients (n=65), mean age 68.1 years; the Phase 2 study included both male and female patients (n=16), mean age 63.3 years. MEASUREMENTS: In the Phase 1 study, patients assigned to escalating dose-area cohorts were evaluated for local skin responses, adverse events, and any other relevant safety data. In the pharmacokinetic study, blood samples were collected pre-dose and for up to 24 hours after administration on Day 2, and analyzed for ingenol mebutate and its primary metabolites. In both studies, safety assessments were performed on Days 2, 3, 8, 15, 29, and 57 (study end). RESULTS: In the Phase 1 study, most adverse events were mild, and all treatment-related adverse events resolved before the end of the study. The 100cm(2) treatment area showed a small increase in the overall intensity of mean composite local skin response scores. There was no quantifiable systemic exposure to ingenol mebutate or its primary metabolites. CONCLUSION: Ingenol mebutate 0.05% gel has a good safety profile when applied to treatment areas up to 100cm(2) with acceptable tolerability and local skin responses. There is no systemic absorption following application to areas of 100cm(2).

PEP005 (ingenol mebutate) gel for the topical treatment of superficial basal cell carcinoma: results of a randomized phase IIa trial.

OBJECTIVES: To evaluate the safety of two applications of PEP005 (ingenol mebutate) gel in superficial basal cell carcinoma. Efficacy was a secondary end-point. METHODS: Randomized, vehicle-controlled, phase IIa study conducted at eight private dermatology clinics in Australia. A total of 60 patients with histologically confirmed superficial basal cell carcinoma (lesion size, 4-15 mm) were randomized to treatment on days 1 and 2 (Arm A) or days 1 and 8 (Arm B) and, within each arm, to ingenol mebutate gel, 0.0025%, 0.01% or 0.05%, or vehicle gel. The main outcome measures were the incidence and severity of adverse events and local skin responses in Arms A and B; lesion clearance at day 85 was a secondary measure. RESULTS: The incidence of adverse events was low. One patient treated with ingenol mebutate gel, 0.05% in Arm A experienced severe flaking/scaling/dryness extending beyond the application site. Non-severe, potentially treatment-related events included erythema extending beyond the application site, application-site pain and headache in two patients each. Six patients in Arm A had one or more severe local skin responses. Efficacy appeared to be dose-related and there was a trend towards higher clinical and histological lesion clearance rates in Arm A compared with Arm B. Histological clearance occurred in five of eight patients (63%) randomized to ingenol mebutate gel, 0.05% in Arm A. CONCLUSIONS: Two applications of ingenol mebutate gel, 0.05%, are safe and have efficacy in patients with superficial basal cell carcinoma.

Randomized, double-blind, double-dummy, vehicle-controlled study of ingenol mebutate gel 0.025% and 0.05% for actinic keratosis.

BACKGROUND: There is a need for improved medical approaches to the treatment of actinic keratosis. Ingenol mebutate, a diterpene ester extracted and purified from the plant Euphorbia peplus, is being evaluated as a topical therapy for actinic keratosis. OBJECTIVE: Assess the efficacy and safety of ingenol mebutate (formerly PEP005) gel at 3 dosing regimens for the treatment of actinic keratosis. METHODS: Patients with non-facial actinic keratoses applied vehicle gel for 3 days, ingenol mebutate gel, 0.025% for 3 days, or ingenol mebutate gel, 0.05% for 2 or 3 days, with an 8-week follow-up period. RESULTS: All 3 active treatments were significantly more effective than vehicle at clearing actinic keratosis lesions, with a dose response observed. The partial clearance rate (primary efficacy end point) for patients treated with ingenol mebutate gel ranged from 56.0% to 75.4% compared with 21.7% for vehicle gel (P = .0002 to P < .0001 vs vehicle). The complete clearance rate was also significantly higher (P < or = .0006) for patients in the ingenol mebutate gel treatment groups (range: 40.0% to 54.4%) compared with vehicle (11.7%), as was the baseline clearance rate (range: 42.0% to 57.9% for ingenol mebutate gel compared with 13.3% for vehicle, P < .0001 to .0007 vs vehicle). The median percentage reduction in baseline actinic keratosis lesions for patients treated with ingenol mebutate gel ranged from 75% to 100% compared with 0% for vehicle gel (P < .0001 vs vehicle). Active treatment was well tolerated at all dosages. The mechanism of action of this agent is the localized induction of necrosis followed by a transient inflammatory response, and this was manifested in most patients as transient local skin responses consisting primarily of erythema, flaking/scaling, and crusting. There was no evidence of treatment-related scarring. LIMITATIONS: Local skin responses may have suggested active treatment to investigators. CONCLUSIONS: Short-course, field-directed therapy with ingenol mebutate gel for actinic keratoses on non-facial sites seems to be effective with a favorable safety profile and potential benefits over topical agents that require a more prolonged course of treatment.

PEP005 (ingenol mebutate) gel, a novel agent for the treatment of actinic keratosis: results of a randomized, double-blind, vehicle-controlled, multicentre, phase IIa study.

The sap of the plant Euphorbia peplus is a traditional remedy for skin conditions, including actinic keratosis. The active constituent of the sap is ingenol mebutate (ingenol-3-angelate), formerly known as PEP005. This randomized, double-blind, vehicle-controlled, phase IIa study investigated the safety (and secondarily the efficacy) of two applications of ingenol mebutate gel in 58 patients with biopsy-confirmed actinic keratosis. Five preselected lesions were treated with ingenol mebutate gel, 0.0025%, 0.01% or 0.05%, or vehicle gel, on days 1 and 2 (Arm A) or days 1 and 8 (Arm B). There were no significant differences in tolerability or efficacy between Arms A and B. Treatment was well tolerated. The most common local skin responses were dose-related erythema, flaking/scaling/dryness and scabbing/crusting. Efficacy was greatest with ingenol mebutate gel, 0.05%, which resulted in complete clinical clearance of 71% of treated lesions (P < 0.0001 vs vehicle gel). In addition, 67% of patients treated with ingenol mebutate gel, 0.05% had clinical clearance of at least four of five treated lesions (P = 0.0185 vs vehicle gel). Ingenol mebutate gel is being developed as a short-course topical therapy for actinic keratosis and non-melanoma skin cancer.