9. Negative serum pregnancy test within 72 hours before starting study treatment on Cycle 1 Day -6 for females of childbearing potential (FCBP). A female of child-bearing potential, defined as a sexually mature woman who: 1) has not undergone a hysterectomy (the surgical removal of the uterus) or bilateral oophorectomy (the surgical removal of both ovaries) or, 2) has not been naturally postmenopausal for at least 24 consecutive months (i.e., has had menses at any time during the preceding 24 consecutive months), may participate providing they agree to the following conditions: