PROS-2 Dose Response Effects of Exogenous Testosterone on the Prostate
Condition: Healthy
Study type: Interventional
Phase: Phase 2/Phase 3

Summary: 
      The investigators will conduct a three-month, randomized, placebo-controlled trial comparing
      the effects of increasing doses of androgen supplementation with Testosterone (T) gel on the
      prostate in healthy men who are treated with acyline to block gonadal androgen production.
    

Detailed description: 
      The investigators overall goals are (i) to determine the relationship between serum and
      prostate tissue hormone concentrations in men in response to increasing doses of exogenous
      androgens; (ii) to determine the impact that alterations in serum and tissue testosterone
      concentrations have on prostate epithelial cell function and phenotype; and (iii) to
      determine the relationships between prostatic androgens and alterations in the tissue
      microenvironment. The investigators will perform a study in healthy, middle-aged men to
      address the following Specific Aims:

      Specific Aims: To compare the dose-response relationships between serum testosterone and
      intraprostatic androgens and androgen action, and serum testosterone and anabolic activity in
      healthy, middle-aged men.

      Hypothesis: The investigators hypothesize that very low levels of serum testosterone will
      lower concentrations of intraprostatic testosterone and dihydrotestosterone (DHT). However,
      when serum testosterone concentrations are within or even above the normal range there will
      be no significant increases in intraprostatic testosterone and dihydrotestosterone. In
      contrast, the investigators expect that anabolic activity will increase with increasing
      concentrations of circulating testosterone.

      Secondarily, the investigators hypothesize that increasing levels of serum testosterone
      beyond the low normal range will have little impact on androgen action within the prostate.

      Approach: The investigators will conduct a randomized, placebo-controlled trial in healthy
      men who are medically castrated and administered one of five different doses of testosterone
      gel (Androgel) for 12 weeks.
    

Intervention name(s): placebo acyline; placebo gel; Testosterone 1% gel 1.25 g; Testosterone 1% gel 2.5 g; Testosterone 1% gel 5.0 g; testosterone 1% gel 10 g; testosterone 1% gel 15 g; Acyline
Intervention type(s): Other; Other; Drug; Drug; Drug; Drug; Drug; Drug
Intervention description(s): Placebo acyline subcutaneous injection every 2 weeks; daily placebo testosterone gel applied transdermally x 12 weeks; testosterone 1% gel 1.25 g daily applied transdermally x 12 weeks; Testosterone 1% gel 2.5 g daily applied transdermally x 12 weeks; Testosterone 1% gel 5.0 g daily applied transdermally x 12 weeks; Testosterone 1% gel 10 g daily applied transdermally x 12 weeks; Testosterone 1% gel 15 g daily applied transdermally x 12 weeks; 300 ug/kg subcutaneous injection every 2 weeks
Other intervention name(s): placebo; placebo; Androgel; Androgel; Androgel; Androgel; Androgel; GNRH antagonist
Intervention MeSH terms: Methyltestosterone; Testosterone; Testosterone undecanoate; Testosterone enanthate; Testosterone 17 beta-cypionate; Acyline
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Treatment
Keywords: Androgen replacement in men