Work

KOH 5% solution versus diclofenac 3% for the treatment of actinic keratosis – Results from a three‐armed RCT

Year: 2025

Type: article

Study designs: Randomized Controlled Trial, Clinical Trial

Abstract: BACKGROUND: Actinic Keratosis (AK) has the potential to progress into malignant cancer, thus necessitating timely and effective treatment. Despite several existing therapies, there is still a need for effective, well-tolerated therapeutic options, especially in the early treatment of patients with few isolated lesions in primary care. OBJECTIVES: To investigate the efficacy and safety of potassium hydroxide (KOH) 5% solution in comparison to diclofenac 3% gel and placebo for the treatment of mild-to-moderate AK. METHODS: In this randomized controlled trial, patients with mild or moderate AK applied KOH or placebo solution double-blinded twice daily for 28 days, followed by a 28-day off-treatment phase (1 treatment cycle) for up to three treatment cycles or until treatment success. In a third arm, diclofenac was applied twice daily for 60 days and evaluated investigator-blinded. The primary endpoint was treatment success, defined as complete clearance (CC) of all initially present AK lesions per patient at the end of treatment (EOT). RESULTS: In total, 631 patients were enrolled. Treatment success was achieved by 45.2% of patients treated with KOH, compared to 23.8% and 22.9% with diclofenac and placebo, respectively. Similarly, complete remission rates for individual lesions were higher with KOH (65.0%) than with diclofenac (45.9%) or placebo (39.9%). KOH showed a faster onset of action, with higher CC rates already after 1 month compared to diclofenac (16.0% vs. 9.2%) and converging efficacies after 6 months. Most adverse reactions were mild and localized, with comparable tolerability of KOH and diclofenac. CONCLUSIONS: KOH 5% solution proved superior to placebo and, when compared to diclofenac 3% gel, demonstrated significantly higher efficacy at EOT, as well as faster onset of action with comparable long-term efficacy and tolerability. KOH 5% solution is a valuable addition to the available treatment options for lesion-directed therapy in patients with mild-to-moderate AK. GOV IDENTIFIER: NCT04552327.

Source: Journal of the European Academy of Dermatology and Venereology

DOI: 10.1111/jdv.70069