Female study volunteers who are not of reproductive potential (who have reached menopause or undergone hysterectomy, bilateral oophorectomy, or tubal ligation) or whose male partner has undergone successful vasectomy with documented azoospermia or has documented azoospermia for any other reason, are eligible without requiring the use of contraception. Acceptable documentation of menopause, sterilization, and azoospermia are as follows: