5. Women of childbearing potential must agree to use adequate contraception prior to study entry, for the duration of the study participation, and for 90 days following completion of therapy. Women of childbearing potential must have a negative serum pregnancy test within 21 days prior to initiation of treatment and a negative urine pregnancy test on the first day of study drug administration. Post-menopausal women must be amenorrheic for at least 12 months to be considered of non-childbearing potential.