- Females of childbearing potential must have a negative serum beta-human chorionic gonadotropin (Beta-hCG) at Visit 1 (Screening) and a negative urine pregnancy test prior to starting study drug (Visit 2). Female subjects of childbearing potential must agree to be abstinent or to use highly effective methods of contraception (eg, condom + spermicide, condom + diaphragm with spermicide, intrauterine device (IUD), or have a vasectomised partner) having starting for at least one menstrual cycle prior to starting study drugs and throughout the entire study period and for 30 days (longer if appropriate) after the last dose of study drug. Those women using hormonal contraceptives must also be using an additional approved method of contraception (as described previously). Perimenopausal women must be amenorrheic for at least 12 months to be considered of non-childbearing potential.