- The effects of bortezomib and PD 0332991 on the developing human fetus at the recommended therapeutic dose are unknown. For this reason, female subjects must either be post-menopausal or surgically sterilized or willing to use an acceptable method of birth control (i.e., a hormonal contraceptive, intra-uterine device, diaphragm with spermicide, condom with spermicide, or abstinence) prior to study entry and for the duration of the study. Male subjects must agree to use adequate contraception prior to study entry and for the duration of study participation. Should a female subject become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.