4. Partners of male and female subjects must use an effective method of contraception (e.g., barrier method, IUD), commencing prior to or at initiation of study drug and continuing for the duration of the study and for 30 days after study drug discontinuation. All females who are of reproductive potential and who are using hormonal contraceptives must have been on a stable dose of the same hormonal contraceptive product for at least 12 weeks prior to dosing and must continue to use the same contraceptive during the study and for 30 days after study drug discontinuation.