28. For women who are not postmenopausal (<12 months of non therapy-induced amenorrhea, with no identified cause other than menopause) and have not undergone surgical sterilization (removal of ovaries and/or uterus): agreement to remain abstinent (refrain from heterosexual intercourse) or use two adequate non hormonal methods of contraception, including at least one method with a failure rate of <1% per year, during the treatment period and for at least 4 months after the last dose of study drug.