Extension of BPS-MR-PAH-203 in Pulmonary Arterial Hypertension (PAH) Patients

• Safety will be assessed by adverse events, physical examination, vital signs, clinical laboratory parameters, and electrocardiogram findings. [ Time Frame: 3, 6 & 12 months & annually thereafter ] [ Designated as safety issue: Yes ]
  

• Unencouraged 6-Minute Walk Test (6MWT) [ Time Frame: 3, 6 & 12 months & annually thereafter ] [ Designated as safety issue: No ]
  
• Clinical Worsening [ Time Frame: 3, 6 & 12 months & annually thereafter ] [ Designated as safety issue: No ]
  

Eligible patients who participated in BPS-MR-PAH-203 and who elect to continue receiving study drug in an open-label extension.Each patient will return to the clinic following enrollment in the study at 3, 6, and 12 months, and annually thereafter for assessment. Patients will be called by study personnel to assess adverse events and concomitant medications at Month 9, and at 3 month intervals following the annual visit.

At the End of Study visit, patients discontinuing study drug will be down-titrated off of BPS-MR at the discretion of the Investigator, at a maximum decrement of one tablet (60µg) b.i.d. per day and a minimum decrement of one tablet (60µg) b.i.d. per week. Likewise, patients who withdraw early from the study will be down-titrated off of BPS-MR in the same manner. Upon completion of down-titration, patients will return to the clinic for a final Closeout visit.

Currently enrolled patients may be invited to participate in an optional four times daily (QID) dosing substudy of BPS-MR with total daily dose of BPS-MR achieved previously in the main study. Patients will return to the clinic for baseline visit, week 12, and then will follow the visit schedule provided to them in BPS-MR-PAH-204 main study.