a Not pregnant or nursing b Of non-childbearing potential (ie, women who have had a hysterectomy, both ovaries removed or medically documented ovarian failure, or are postmenopausal women > 50 years of age with cessation [for 12 months] of previously occurring menses), or c Of childbearing potential (ie, women who have not had a hysterectomy, both ovaries removed, or no medically documented ovarian failure). Women ≤ 50 years of age with amenorrhea will be considered to be of childbearing potential. These women must have a negative serum pregnancy test at screening and a negative urine pregnancy test on the Baseline/Day 1 visit prior to randomization. They must also agree to one of the following from 3 weeks prior to Baseline/Day 1 until 30 days after the last dose of treatment or 3 months after last dose of Ribavirin: