- For women of childbearing potential a serum pregnancy test will be done up to 7 days before enrolment (and it must be negative) and an agreement to use one highly-effective form of non-hormonal contraception (true abstinence, vasectomy, oophorectomy/hysterectomy, IUD) or two effective forms of non-hormonal contraception (e.g., condoms plus spermicidal agent) at study entry (to be put in place within 2 weeks prior to enrolment), during the administration of T-DM1 and for 7 months after the last administration of T-DM1 will be obtained