Use of adequate contraception, e.g. any of the following methods plus condom: implants, injectables, combined oral or vaginal contraceptives, intrauterine device Sexually abstinent A vasectomised sexual partner (vasectomy at least 1 year prior to enrolment) Surgically sterilised (including hysterectomy) Postmenopausal, defined as at least 1 year of spontaneous amenorrhea (in questionable cases a blood sample with simultaneous levels of follicle-stimulating hormone above 40 U/L and estradiol below 30 ng/L is confirmatory)