Patients who meet the inclusion/exclusion criteria will enter the Treatment Phase at a Baseline visit. Patients will begin taking one BPS-MR tablet (60µg) twice daily (b.i.d.) escalating by one tablet b.i.d. each week to a maximum dose of 600µg (ten tablets) b.i.d or until the patient reaches their MTD. Following the achievement of the MTD, patients will be down-titrated off BPS-MR in weekly one tablet b.i.d. decrements. Patients may, alternatively, elect to continue taking the study drug at their MTD in a separate open-label extension study.