Dutasteride Versus Placebo and Finasteride in Men With Androgenetic Alopecia
Condition: Androgenetic Alopecia
MeSH terms: Alopecia; Alopecia Areata
Study type: Interventional
Phase: Phase 3

Summary: 
      The purpose of this six month study is to show that dutasteride is safe and more effective
      than placebo, and at least as safe and effective as finasteride in treating hair loss in men
      with androgenetic alopecia. Three doses of dutasteride will be investigated.
    

Detailed description: 
      Androgenetic alopecia is a common, androgen-induced, pattern of progressive loss of scalp
      hair with an onset at any age after puberty in genetically predisposed people. The influence
      of androgens on scalp hair growth is mediated by local and systemic conversion of
      testosterone to dihydrotestosterone , by the enzyme 5 alpha-reductase. 5 alpha-reductase has
      been shown to exist as 2 isoenzyme forms, Type 1 and Type 2. Type 1 is predominantly located
      in the skin, both in the hair follicles and sebaceous glands, and is also found in the liver
      and kidney . Type 2 is the dominant form in male genitalia, including the prostate, although
      it has also been reported to be present in the inner root sheath of the hair follicle. The
      presence of both isoenzymes in the hair follicles suggests that both forms are likely to be
      important in the pathogenesis and treatment of androgenetic alopecia. Inhibition of both Type
      1 and Type 2 5 alpha-reductase may be expected to more effectively reduce systemic and local
      dihydrotestosterone levels than inhibition of either isoenzyme alone.

      Finasteride is a selective Type 2 5 alpha-reductase inhibitor that is currently the only
      approved oral treatment for androgenetic alopecia worldwide. Dutasteride inhibits both Type 1
      and Type 2 5alpha-reductase and is approved in more than 80 countries for the treatment of
      benign prostatic hyperplasia, and in Korea for the treatment of hair loss. Dutasteride is
      approximately 3 times as potent as finasteride at inhibiting Type 2 5 alpha-reductase and
      more than 100 times as potent at inhibiting Type 1 5 alpha-reductase.

      In a Phase II double-blind, placebo-controlled clinical study (ARIA2004) conducted in the
      United States, dutasteride demonstrated significant increases in target area hair count, as
      compared with placebo, as early as 12 weeks. In a Phase III double- blind, placebo-controlled
      clinical study conducted in Korea, dutasteride 0.5 milligram (mg) demonstrated significant
      increases in target area hair count, as compared with placebo, at 24 weeks. This 6 month
      study is being conducted to provide additional evidence of the efficacy and safety of three
      doses of dutasteride (0.02, 0.1 and 0.5mg) in the treatment of androgenetic alopecia, and
      more specifically, to characterize the dose-response relationship in an ethnically-diverse
      population. Treatment arms will be equally balanced with approximately 180 per arm.
    

Intervention name(s): 1mg Finasteride active; 0.02mg dutasteride; 0.1mg dutasteride; 0.5mg dutasteride; Finasteride placebo; Dutasteride placebo
Intervention type(s): Drug; Drug; Drug; Drug; Drug; Drug
Intervention description(s): 1mg finasteride active, by mouth once daily; 0.02mg dutasteride active, by mouth once daily; 0.1mg dutasteride active, by mouth once daily; 0.5mg dutasteride active, by mouth once daily; finasteride placebo, by mouth once daily; dutasteride placebo, by mouth once daily
Intervention MeSH terms: Finasteride; Dutasteride
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment