4. A female of childbearing potential must have a negative serum at screening and negative urine pregnancy test prior to treatment with study therapy. In addition, sexually active females of childbearing potential must agree to use two of the following adequate forms of contraception methods simultaneously: oral, injectable or implantable hormonal contraception; tubal ligation; intrauterine device; barrier contraceptive with spermicide; or vasectomized partner for the duration of the study and the follow-up period. Males, including those who have had a vasectomy, must agree to use barrier contraception (latex condoms) when engaging in reproductive sexual activity with a female of childbearing potential for the duration of study and follow-up period.