4. Male subjects and their partners who are not using two highly effective methods of contraception, comprising a barrier method (e.g. condom with spermicidal gel) plus use by the female partner of a second method of contraception (e.g. hormonal, IUD, barrier method such as occlusive cap with spermicide). These measures should be in place for the entire duration of the study up the Study Completion visit, and males should refrain from fathering a child in the 12 months following the last dose of study medication.