A multicenter, randomized, vehicle-controlled phase 2 study of blue light photodynamic therapy with aminolevulinic acid HCl 20% topical solution for the treatment of actinic keratoses on the upper extremities: the effect of occlusion during the drug incubation period.

BACKGROUND: Photodynamic therapy (PDT) with aminolevulinic acid (ALA) has been shown to be safe and effective in the treatment of actinic keratoses (AKs) of the face and scalp. A recent small study has suggested that ALA-PDT can be effective for AKs of the dorsal hands/forearms. However, studies designed to provide sufficient statistical power to test this hypothesis are lacking in the literature. OBJECTIVES: To determine and compare the safety and efficacy of blue light ALA-PDT vs blue light placebo vehicle (VEH) in the treatment of AKs of the upper extremities and to evaluate the effect of occlusion after application of ALA vs VEH. METHODS: ALA or VEH was applied to both dorsal hands/forearms for the 3-hour incubation period before blue light treatment (10 J/ cm2). One extremity of each subject was covered with occlusive dressing during the incubation period. Treatment was repeated at week 8 if any AK lesions remained. RESULTS: The median AK lesion clearance rate at week 12 was 88.7% for extremities treated with occluded ALA (ALA+OCC), 70.0% for extremities treated with nonoccluded ALA, 16.7% for extremities treated with occluded VEH (VEH+OCC), and 5.6% for extremities treated with nonoccluded VEH (P<.0001). ALA+OCC resulted in a significantly higher clearance rate compared with the nonoccluded extremity at weeks 8 (P=.0006) and 12 (P=.0029). Thirty-four percent (12/35) of extremities treated with ALA+OCC had complete clearance of lesions at week 12 compared with 0% (0/35) of extremities treated with VEH+OCC (P=.0002). The safety pro!le in this study is consistent with previously reported side effects of the therapy. CONCLUSION: Blue light ALA-PDT following a 3-hour incubation appears efficacious for AK clearance of the upper extremities. Incubation using an occlusive dressing significantly increases the efficacy of the procedure and also increases the incidence and severity of some acute inflammatory side effects of PDT.

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.