4. Females participating in the study must either not be of childbearing potential (hysterectomy, bilateral oophorectomy, medically documented ovarian failure, or >50 years of age with cessation of menses for at least 12 months due to ovarian failure) or using efficient double contraception: hormonal contraception (including patch, contraceptive ring, etc.), intra-uterine device, or other mechanical contraception method + condom or diaphragm or spermicide for the full duration of the study and for 1 month after the end of treatment.