In this study, we propose oral dosing of GIPET enhanced oral acyline (MER-104) to determine if this potentially useful compound is safe and effective at suppression of gonadotropins after oral dosing in man. Hypothesis: A single dose of Acyline will suppress gonadotropins, and testosterone, estradiol and dihydrotestosterone (DHT) for 24 hours in man, and the magnitude and duration of the suppression will increase with increasing doses of Acyline.

The purpose of this study is to test how the body responds to a new oral form of acyline and to also look at the safety of oral acyline. Acyline temporarily blocks the production of the hormone testosterone in normal men. It has been given to over 100 men in an injection form. This study will be testing acyline in a pill form. This is the first time the pill form has been tested in humans. This study may help develop an oral form of a testosterone-blocker, which may be useful in the treatment of diseases such as prostate cancer, premature puberty and possibly in a male contraceptive. This study requires three 12-hour blood draw periods for pharmacokinetics (PK) testing. PK testing looks to see how much study drug is in the blood. This gives information about how the body handles and gets rid of the study drug.