2. Subjects of childbearing potential who are unwilling to take appropriate precautions (throughout the study from screening, including 30 days after discontinuation of the study drug) to avoid becoming pregnant or fathering a child. Females of non-childbearing potential are defined as women who (a) are equal to or greater than 55 years of age with history of amenorrhea for 1 year, OR (b) are surgically sterile for at least 3 months. For females of childbearing potential, or for males, appropriate precautions are those that are at least 99% effective in preventing the occurrence of pregnancy. These methods should be communicated to the subjects and their understanding confirmed: •Complete abstinence from sexual intercourse •Double barrier methods •Condom with spermicide in conjunction with use of an intrauterine device (IUD) •condom with spermicide in conjunction with use of a diaphragm •Oral, injectable, or implanted contraceptives •Tubal ligation or vasectomy (surgical sterilization)