22. Pregnant or nursing woman, or woman of childbearing potential who is not using an effective contraceptive method during the study, e.g. oral (stable doses for at least three months prior to Screening) or injectable (stable doses for at least two months prior to Screening) contraceptives, implantation of levonorgestrel system and intrauterine devices (for at least two months prior Screening), barrier methods (combination of diaphragm and spermicide or condom and spermicide).