New treatments available for actinic keratosis, methotrexate toxicity

In January, FDA approved ingenol mebutate (Picato) gel as a topical treatment of actinic keratosis. The mechanism of action by which ingenol mebutate gel induces cell death in actinic keratosis lesions is not known.

Efficacy. Ingenol mebutate's efficacy was established in 4 randomized, vehicle-controlled clinical studies. The primary efficacy end point was complete and partial clearance of actinic keratosis lesions within the treatment area at 8 weeks. Studies 1 and 2 (n=547) assessed efficacy of the gel applied to the face and scalp, while studies 3 and 4 (n=458) evaluated its efficacy when applied to the trunk and extremities. Complete and partial clearance occurred more commonly in the ingenol mebutate group compared to control in studies 1-4. Recurrence rates after being off drug for 12 months ranged between 50% and 54%.

Dosage. Ingenol mebutate gel (0.015%) should be applied once daily for 3 consecutive days to the face or scalp. For lesions on the trunk or extremities, ingenol mebutate gel (0.05%) should be administered for 2 consecutive days. The treatment area should not exceed 25 cm². Treatment should be applied evenly to the lesion site and allowed to dry for 15 minutes. The application site should remain untouched for a period of 6 hours, but may subsequently be washed with mild soap after this time. Ingenol mebutate should not be applied to damaged skin. Patients should be instructed to wash hands after each application.