18. No adequate contraception 1 month before study and until 2 month after study completion, e.g. not any of the following: implants, injectables, combined hormonal contraceptives, hormonal IUD (intrauterine device), sexual abstinence for at least 1 month prior to first study drug administration, vasectomised partner (vasectomy performed at least 1 year prior to enrolment), or surgical sterilisation (including hysterectomy). Females, who do not have a vasectomised partner, are not sexually abstinent or surgically sterile will be asked to use an additional barrier method (e.g. condom).