A Randomized Double-Blind Parallel-Group Study to Evaluate the Long-Term Effects of a Medical Device Containing 0.3% Octatrienoic Acid in the Treatment of Grade III Actinic Keratosis

Introduction: Actinic keratosis (AK) consists of skin lesions with a milder degree of keratinocytic atypia. It can be also referred to as “field of cancerization,” which can potentially evolve to cutaneous squamous cell carcinoma (SCC). Several therapeutic options are currently available, but not all are indicated on hyperkeratotic lesions. This study aimed to test the efficacy and tolerability of a medical device containing 2,4,6-octatrienoic acid and urea for the treatment of hyperkeratotic AK lesions. Methods: Seventy male and female subjects with grade III AK were enrolled in this randomized double-blind parallel-group study. The product was applied once daily for three consecutive months. The primary efficacy endpoint was the reduction in the mean number of AK lesions per subject from baseline (T0) to the end of the trial (T1) and 3 months after the end of the treatment period (T2). Therefore, clearance of target AK lesions at the end of the treatment period and local skin reaction score (LSR) versus baseline were evaluated. Results: There was a decrease of mean values from baseline to visit T2 in both treatment groups, but the decrease (versus baseline values) was more evident in the Kerà K2 group than in the placebo group (−42.78, SD 26.53, versus −6.20, SD 31.57), and the difference was statistically significant (p < 0.001). For 70 subjects (56.7%) in the Kerà K2 group and 3 (11.54%) in the placebo group, a significant (p < 0.005) partial clearance was evidenced. The product was well tolerated, and no serious adverse events were reported during the duration of the trial. Subject self-assessment of acceptability, local tolerability, and the cosmetic result was good at both T1 and T2 for both groups. Conclusions: The medical device has demonstrated good efficacy in the reduction of visible AKs, encouraging its use.