<qa>  What is a positive urine or beta-human chorionic gonadotropin serum- Females of childbearing potential must have a negative urine or beta-human chorionic gonadotropin serum pregnancy test within 2 weeks prior to Cycle 1, Day 1. A urine pregnancy test should be repeated prior to chemotherapy if not conducted within 72 hours of start of treatment. Female subjects of childbearing potential must agree to be abstinent or to use a highly effective method of contraception e.g., condom spermicide, condom diaphragm with spermicide, intrauterine device IUD, or have a vasectomized partner having started for at least one menstrual cycle prior to starting study drug and throughout the entire study period and for 30 days longer if appropriate after the last dose of study drug. Perimenopausal women must be amenorrheic for at least 12 months to be considered of nonchildbearing potential. Male subjects who are not abstinent or who have undergone a successful vasectomy, who are partners of women of childbearing potential must use, or their partners must use, a highly effective method of contraception e.g., condom spermicide, condom diaphragm with spermicide, IUD starting for at least one menstrual cycle prior to starting study drug and throughout the entire study period and for 30 days longer if appropriate after the last dose of study drug. Subjects with partners using hormonal contraceptives must also be using an additional approved method of contraception as described previously. 