A Randomized, Double-Blind, Placebo and Active Controlled Phase II Study to Evaluate the Safety and Efficacy of Novel Dutasteride Topical Solution (0.01%, 0.02%, and 0.05% w/v) in Male Subjects With Androgenetic Alopecia

Abstract

Introduction Oral dutasteride has demonstrated superiority over finasteride in treating androgenetic alopecia (AGA). We have developed a novel topical dutasteride formulation, which has shown promising efficacy, safety, and tolerability in preclinical studies. The present study objective is to compare the efficacy and safety of dutasteride topical solutions (0.01%, 0.02%, and 0.05% w/v) with placebo and oral finasteride (1 mg/day) in AGA males. Methods In this phase II study, 135 AGA males (20-60 years of age) were randomized to receive dutasteride topical solution (0.01%, 0.02%, 0.05% w/v), finasteride (1 mg), or placebo daily for 24 weeks. The primary endpoint was target area hair count (TAHC) within 1 cm² at the vertex at week 24. Secondary endpoints included TAHC at week 12 and target area hair width (TAHW), male hair growth questionnaire (MHGQ) score, and investigator global photography assessment (GPA) at week 12 and week 24. Results Dutasteride topical solution demonstrated a dose-dependent increase in TAHC and TAHW vs placebo at week 24 (p≤0.01). The 0.05% dutasteride solution significantly improved TAHC vs finasteride at week 24 (p=0.0083). More patients in the 0.05% dutasteride group achieved a GPA score of ≥+2 and an MHGQ score ≤ 2 at week 24 than those on finasteride. No irritation was reported in active treatment groups. Dutasteride caused modest changes in serum testosterone/dihydrotestosterone, while finasteride caused moderate changes. Conclusion Dutasteride topical solution (0.05% w/v) demonstrated to be more efficacious than finasteride (1 mg/day) in treating male AGA.

Keywords: 5-alpha reductase selective inhibitors; androgenetic alopecia; dutasteride; finasteride; hair loss; male pattern alopecia.