Efficacy and safety of follow‐up field treatment of actinic keratosis with ingenol mebutate 0·015% gel: a randomized, controlled 12‐month study

Summary Background Ingenol mebutate (IngMeb) is a novel patient‐applied topical field therapy for actinic keratosis. Objectives To demonstrate the efficacy and safety of follow‐up IngMeb field treatment of actinic keratoses ( AK s) present at 8 weeks after initial treatment or emerging in a previously cleared field. Methods In this phase III , randomized, double‐blind study in patients with 4–8 clinically visible AK s within a contiguous 25‐cm 2 treatment area on the face or scalp, all patients were treated initially with IngMeb 0·015% gel for three consecutive days. If lesions were present in the field at 8 weeks, or emerged at weeks 26 or 44, patients were randomized (2 : 1) to follow‐up IngMeb or vehicle gel for three consecutive days. The main outcome was complete clearance rates of AK s 8 weeks after randomization. Results Of 450 patients who received initial treatment with IngMeb, 61·6% demonstrated complete clearance at 8 weeks. Patients with AK s present at 8 weeks or emerging at weeks 26 or 44 were randomized to IngMeb ( n = 134) or vehicle ( n = 69). IngMeb achieved a higher complete clearance rate than vehicle 8 weeks after randomization in AK s present at 8 weeks (46·7% vs. 18·4%; P < 0·01) and in emergent AK s (59·5% vs. 25·0%; P = 0·01). Based on those who completed 12 months of follow‐up ( n = 340), the overall 12‐month clearance rate was estimated at 50·0%. Follow‐up IngMeb treatment was well tolerated. Conclusions This study demonstrated the long‐term benefit of IngMeb 0·015% gel for initial and follow‐up therapy of AK s.