The use of resiquimod gel 0.03%/0.01% is effective for the treatment of actinic keratosis (AK) on the balding scalp, forehead, and face, according to the results of a multicenter study (ClinicalTrials.gov identifier: NCT01583816) published in the British Journal of Dermatology.
The investigators sought to explore the optimal dosing regimens of the toll-like receptor (TLR)7/8 antagonist resiquimod for the treatment of AK with respect to efficacy, safety, and tolerability. A total of 217 patients with AK lesions were randomly assigned to resiquimod 0.03% gel once-daily application in one of three treatments arms: 3 times a week for 4 weeks (Arm 1); 7 times within 2 weeks (Arm 2); or 5 times in 1 week (Arm 3). In 2 additional treatment arms, patients applied either resiquimod gel 0.01% 3 times weekly (Arm 4), or resiquimod 0.03% gel 3 times weekly (Arm 5), up to a biologic end point defined by skin erosion or for a maximum duration of 8 weeks. Clearance of lesions was evaluated both clinically and histologically.
Eligible patients were >age 18 ≥2 clinically (1 biopsied) diagnosed AK lesions on the balding scalp, forehead, or face. All patients self-administered the gel topically to predefined treatment areas based on dosage and trial schedules.
Complete clinical clearance of lesions ranged from 56% to 85%, with the highest rate of clearance reported in Arm 2. Resiquimod 0.03% gel was more effective than resiquimod 0.01% gel. Clearance rates in Arms 1, 2, and 3, achieved with 24, 14, and 10 gel applications, respectively, were comparable and were higher than with placebo.
In the intent-to-treat population, the overall complete clinical clearance rate at the conclusion of the study was 67% (P =.001 vs placebo), 72% (P =.004 vs placebo), 70% (P <.001 vs placebo), 56% (P =.009 vs placebo), and 74% (P <.001 vs placebo) in Arms 1, 2, 3, 4, and 5, respectively.
The investigators concluded that resiquimod 0.03% gel is more effective than resiquimod 0.01% gel. From a safety and a tolerability perspective, the lower concentration and shorter duration of resiquimod application are preferable. In Arms 2 and 3, the clinical response was achieved with fewer applications of the gel. The dosing regimens that used the biologic end point (Arms 4 and 5) were equally efficacious as predefined treatment durations and may thus be appropriate for personalized AK therapy.
Stockfleth E, Hofbauer GFL, Reinhold U, et al. Topical resiquimod dosing regimens in patients with multiple actinic keratosis: a multi-centre, partly placebo-controlled, double-blind, clinical trial [published online September 1, 2018]. Br J Dermatol. doi:10.1111/bjd.17124