DNA Repair Enzyme Containing Lip Balm for the Treatment of Actinic Cheilitis: A Pilot Study

June 2019 | Volume 18 | Issue 6 | Original Article | 576 | Copyright © June 2019

Amanda Rosenthal BA,a,b Alexis Lyons MD,c Lauren Moy MD,d Alexis Wilson,b Kian Mohamadi BS,b Jennifer Herrmann MD,b,e Rebecca Tung MDd

aUniversity of Miami Miller School of Medicine, Miami, FL bMoy-Fincher-Chipps Facial Plastics & Dermatology, Beverly Hills, CA cHenry Ford Hospital, Detroit, MI dLoyola University Medical Center,Maywood, IL eHarbor-UCLA Medical Center, Torrance, CA

Abstract
Background: DNA repair enzymes have been shown to reduce actinic keratoses and non-melanoma skin cancers, but their use for the treatment of actinic cheilitis has not been studied.

Objective: The purpose of this pilot study was to examine the efficacy of a DNA repair enzyme lip balm containing T4 endonuclease in reducing the severity of actinic cheilitis in patients who applied the lip balm twice daily for 3 months.

Methods: We performed a prospective study in which 29 patients with a diagnosis of actinic cheilitis underwent a 3-month trial using a topical DNA repair enzyme lip balm containing T4 endonuclease applied to the lips twice daily. The primary, objective outcome was percent of actinic lip involvement, measured using computer software by dividing the calculated affected surface area by the calculated total surface area. Additional outcomes included pre- and post-intervention determination of an actinic cheilitis score on the Actinic Cheilitis Scale, which visually and tactilely quantifies the percentage of lip involvement, amount of roughness, erythema, and tenderness as well as a physician assessment using the Global Aesthetic Improvement Scale.

Results: Twenty-five of the 29 enrolled patients completed the trial. The lip balm significantly decreased the percentage of affected lip surface area (P<0.0001). According to the Actinic Cheilitis Scale, data demonstrate that the lip balm significantly decreased the percentage of lip involvement (P=0.002), amount of roughness (P=0.0012)), erythema (P=0.0020), and tenderness (P=0.0175). The total Actinic Cheilitis Scale score also significantly improved after the 3-month treatment period (P<0.0001). According to the Global Aesthetic Improvement Scale, the average score for all 26 patients was 1.04.

Conclusion: This study suggests that topical DNA repair enzyme lip balm containing T4 Endonuclease could potentially be a safe and efficacious way to improve and treat actinic cheilitis.

J Drugs Dermatol. 2019;18(6):576-579.

INTRODUCTION

Actinic cheilitis (AC), also known as actinic keratosis (AK) of the lips, is a common lesion of the lower lip caused by chronic exposure to ultraviolet light.1 Among sun-exposed populations, the prevalence of AC is nearly 10%, and most commonly affects white, older males.2 AC is characterized by scaling, dryness, edema, erythema, tenderness, fissuring, crusting, and discoloration of the affected lip.3 As a precancerous condition, anywhere from 10 to 30% of cases can potentially undergo malignant transformation into squamous cell carcinoma (SCC).4 Further, almost all SCCs located on the lower lip originate from AC.1

The current standard of care for actinic cheilitis includes cryotherapy, electrocautery, vermilionectomy, or laser ablation.5 While there are no FDA-approved topical therapies, retinoids, 5-fluorouracil, imiquimod, and photodynamic therapy are often used by practicing clinicians.6 While these procedures and topical methods confer acceptable clinical improvement, many are associated with significant side effects including pain, irritation, redness, edema, and significant downtime. The discomfort caused by these therapies often leads to patient-initiated discontinuation and, subsequent, reduced clinical efficacy. From the patient perspective, there is a need for less inflammatory, more comfortable treatment approaches for AC.

Topical DNA repair enzymes may serve as a promising option for the management of actinic cheilitis and the prevention of skin cancer development. Studies have demonstrated the efficacy of topical DNA repair enzymes, specifically, T4 endonuclease V (T4N5), in decreasing basal cell carcinomas, squamous cell carcinomas and actinic keratoses,7-9 however, these enzymes have yet to be studied in the management of AC. The