11. Female subjects of childbearing potential must be practising true abstinence when this is in line with the preferred and usual lifestyle of the subject (Periodic abstinence, e.g. calendar, ovulation, symptothermal, post-ovulation methods and withdrawal are not acceptable methods of contraception), or be using and willing to continue using a medically acceptable form of birth control for at least 1 month prior to screening (at least 3 months for hormonal contraceptives) and for at least 1 month after the last study drug administration