3. If female, the subject is (a) at least 1 year post-menopausal, or (b) surgically sterile, or (c) of child-bearing potential, with a negative serum pregnancy test result prior to study enrollment, who agrees to use adequate contraception for 6 months. Adequate contraception is defined as abstinence or a reliable method of birth control (e.g., a hormonal contraceptive, intra-uterine device, implantable or injectable contraceptives (Norplant® or Depo-Provera®), diaphragm, or condom with spermicide).