- Females of childbearing potential (FCBP) [An FCBP is a sexually mature woman who: 1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been naturally postmenopausal for at least 24 consecutive months (i.e., who has had menses at any time in the preceding 24 consecutive months)] must agree to refrain from becoming pregnant for 28 days prior to initiation of study drug, while on study drug and for 28 days after discontinuation of study drug and must agree to regular pregnancy testing during this timeframe.