- Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, during the study participation, and for four months after the last dose of the drug; women of child-bearing potential must have a negative serum pregnancy test within 14 days prior to registration and agree to use effective contraception throughout the treatment period and for 4 months after the last dose of study treatment; should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately