BPS-314d-MR-PAH-303 (BEAT OLE)

Subjects will sign an informed consent to continue treatment for PAH with esuberaprost sodium
tablets in this open-label extension (OLE) study. At the Enrollment Visit for this study,
subjects will begin a blinded transition from the BPS-314d-MR-PAH-302 study to the OLE study
over a 4-week period. The first dose for all subjects in this OLE study will be 2 tablets.
During this blinded transition period, those subjects on active study drug in the
BPS-314d-MR-PAH-302 study will continue with blinded active study drug 4-times daily (QID);
those subjects on placebo study drug will receive one active tablet and one placebo tablet
QID (blinded) during the first 2 weeks and increase to 2 active tablets QID (blinded)
thereafter. After the first dose, the investigator may adjust the dose as medically
warranted. The maximum dose for this study is 30 μg QID with a minimum accepted dose as 15 μg
QID. For the first 4 weeks, contact with the subject should occur weekly to ensure
up-titration to the fixed dose is tolerated and assess adverse events (AEs).

Subjects will return to the clinic at Week 4 to be supplied open-label esuberaprost sodium
tablets and complete protocol specified procedures. At the Week 4 Visit, subjects will be
dosed with two 15 μg tablets (30 μg total), administered orally QID (provided the target dose
is tolerated) or follow the Investigator's (or designee's) directions if adjustment is
needed. Following the Week 4 Visit, each subject will return to the clinic at Months 3, 6, 9,
and 12, and quarterly thereafter for assessments.

At the conclusion of the study or if a subject discontinues the study prematurely, subjects
will return to the clinic for an End-of-Study (EOS) Visit. Subjects will be provided
instructions about down titration off esuberaprost sodium tablets by the investigator.

Inclusion Criteria:

1. Subject must have been actively participating in Study BPS-314d-MR-PAH-302 when the
sponsor concluded that study.

2. In the Investigator's opinion, subject must be competent to understand the information
given in the Institutional Review Board (IRB) or Independent Ethics Committee (IEC)
approved informed consent form (ICF) and must sign the form prior to the initiation of
any study procedures.

3. Women of child-bearing potential (defined as less than 1 year post-menopausal and not
surgically sterile) must be practicing abstinence or using two highly-effective
methods of contraception (defined as a method of birth control that results in a low
failure rate, i.e., less than 1% per year, such as approved hormonal contraceptives,
barrier methods [such as a condom or diaphragm] used with a spermicide, or an
intrauterine device). Subject must have a negative pregnancy test at the
BPS-314d-MR-PAH-302 EOS Visit / BPS-314d-MR-PAH-303 Enrollment Visit.

4. Subject must be willing and able to comply with study requirements and restrictions.

Exclusion Criteria:

1. Subject is pregnant or lactating.

2. Subject is scheduled to receive another investigational drug, device, or therapy
during the course of the study.

3. Subject is taking or intends to take any prostacyclin / prostacyclin analog or IP
receptor agonist (EXCEPT FOR treprostinil, inhaled [Tyvaso®]).

4. Subject has any other clinically significant illness or other reason that, in the
opinion of the investigator, might put the subject at risk of harm during the study or
might adversely affect the interpretation of the study data.