- Patients must not be pregnant/breast feeding and must agree to practice adequate contraception. Women of childbearing potential must have a negative B-HCG pregnancy test documented within 14 days prior to treatment. Patients must not be pregnant because of the uncertainty that study drug may be potentially embryotoxic. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control) prior to study entry, for the duration of study participation, and continue approximately 12 weeks after the study is completed. If condoms are used as a barrier contraceptive, a spermicidal agent should be added to ensure that pregnancy does not occur. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.