Long-Term (Over 10 Years) Evaluation of Efficacy and Safety of Finasteride in Japanese Men with Androgenetic Alopecia: Summary of Three Investigations

Introduction: Finasteride has been the standard medical treatment for androgenetic alopecia (AGA) for over 20 years. We started AGA treatment with finasteride in 1999 in Japan, and have demonstrated 3 investigations as long-term and/or large-scale studies (3,177 cases in 2.5 years, 801 cases in 5 years, 532 cases in 10 years, respectively). The objective of this study is to summarize the three investigations, and to consider it as a base for future studies over the next 20 to 30 or more years. Methods: Vertex photographs and/or forehead photographs were taken and recorded for every patient at each examination and used for evaluation for more than 20 years. Efficacy was assessed using the Norwood-Hamilton scale (N-H) and the modified global photographic assessment (MGPA) score, which is the standardized 7-point rating score using scalp photographs. Adverse reactions were assessed through self-reported evaluations by patients in two investigations Results: All three of the investigations demonstrated high evaluations of improvement (MGPA≧5; 87.1%, 99.4%, and 91.5%, respectively), and higher evaluations of prevention of disease progression (MGPA≧4; 99.6%, 100%, and 99.1%, respectively). Furthermore, the early-stage AGA group (N-H I-III at first visit) and the younger group (less than 40 years of age at first visit) showed more improvement with long-term AGA treatment with finasteride than the other groups did. Two of the investigations showed safety of long-term AGA treatment with finasteride, revealing the low onset rates of adverse reactions (adverse reactions: 0.7% in 2.5 years and 6.8% in 10 years, respectively). Neither of the two investigations recognized Post Finasteride Syndrome adverse reaction at all. Conclusion: Long-term (greater than 10 years) AGA treatment with finasteride 1 mg/day demonstrated a high efficacy and safety based on large-scale studies in Japanese men. For patients at the early stage of classification of AGA (within N-H I-III or earlier) and/or younger than 40 years of age, we recommend starting treatment with 1 mg/day finasteride.