 4. Pregnant, breast-feeding or planning a pregnancy during the study and women of childbearing potential not using adequate contraception. Women of childbearing potential not abstinent or using a highly effective method of birth control defined as those which result in a low failure rate i.e. 1 per year when used consistently and correctly such as implants, injectables, combined oral contraceptives, hormonal IUDs, tubal ligation or vasectomised partner started at least 4 weeks prior to screening. 