Efficacy, Safety, and Tolerability of 4% 5-Fluorouracil Cream in a Novel Patented Aqueous Cream Containing Peanut Oil Once Daily Compared With 5% 5-Fluorouracil Cream Twice Daily: Meeting the Challenge in the Treatment of Actinic Keratosis.

BACKGROUND: Actinic keratosis (AK) is a neoplastic keratosis and a precursor of squamous cell carcinoma (SCC).

OBJECTIVE: We are presenting data on a novel formulation of 4% 5-Fluorouracil (5-FU) in an aqueous vehicle cream containing peanut oil (Tolak) with once daily application versus treatment with 5% 5-FU twice daily for 4 weeks.

METHODS: 1) A dose ranging study of 4% 5-FU cream once or twice daily for 2 or 4 weeks and its vehicle, compared to 5% 5-FU cream twice daily for 4 weeks in 121 subjects. 2) A double-blinded multicenter study involving 841 subjects for non-inferiority and safety of 4% 5-FU cream once daily vs 5% 5-FU cream twice daily over 4 weeks with 100% and 75% clinical clearance of AK's.

RESULTS: 4% 5-FU qd q4wks achieved 100% clearance in 80% and 75% clearance in 100% of subjects vs 75% and 95% respectively with 5% 5-FU bid q4wks. 4% 5-FU qd2wks achieved 100% clearance in 60% and 75% clearance in 85% of subjects. 4% 5-FU qd q4wks recorded 65 adverse events and 30% application site skin irritation versus 71 events and 60% with 5% 5-FU bid q4wks. 4% 5-FU exceeded non-inferiority by 1.32% with sub-analysis for higher percentage of severely affected patients. 4% 5-FU showed 75% clearance of AK's in 80.5% vs 80.2% for 5% 5-FU with superior tolerability.

CONCLUSIONS: 4% 5-FU cream is a novel, efficacious, superior tolerated once daily topical treatment for better compliance and treatment outcome. The peanut oil component is safe even in peanut-allergic patients.

J Drugs Dermatol. 2016;15(10):1218-1224.