Inhaled Treprostinil in Patients With Pulmonary Hypertension Due to Chronic Obstructive Pulmonary Disease (PH-COPD)

This is a multi-center, open-label study for eligible subjects who completed all scheduled
study visits during the Treatment Period of Study RIN-PH-304.

Subjects who provide informed consent for this open-label extension study on or prior to the
final study visit of RIN-PH-304 may participate in the study, provided all other eligibility
United Therapeutics Corp. RIN-PH-305 Original Protocol Lung Biotechnology PBC Inhaled
Treprostinil Version Date 05 September 2018 Confidential Page 12 criteria are met. The
RIN-PH-304 final study visit and the RIN-PH-305 Enrollment Visit will occur on the same day.

All subjects will reinitiate inhaled treprostinil at a dose of 3 breaths at 18 micrograms
(mcg) 4 times daily (QID) during waking hours. Study drug doses should be maximized to
tolerability throughout the study, and dose titrations should occur as rapidly as possible
(as directed by the Investigator) with a target dosing of 12 breaths (72 mcg) four times a
day (QID) or to maximum tolerability. If there are adverse events (AEs) that are dose
related, the dosing can be adjusted to tolerability.

Study visits will occur at enrollment, Week 6, and quarterly thereafter. The study may be
terminated at any time by the Sponsor for reasons that may include, but are not limited to,
commercial availability of inhaled treprostinil for PH-COPD and Sponsor termination of the
development for the indication of PH-COPD.

Inclusion Criteria:

1. Subject voluntarily gives informed consent to participate in the study.

2. Subject participated in Study RIN-PH-304 and completed all scheduled study visits.

3. Women of childbearing potential (defined as less than 1 year post-menopausal and not
surgically sterile) must be practicing abstinence or using 2 highly effective methods
of contraception (defined as a method of birth control that results in a low failure
rate, [less than 1% per year], such as approved hormonal contraceptives, barrier
methods [such as condom or diaphragm] used with a spermicide, or an intrauterine
device). Subject must have a negative urine pregnancy test at the Enrollment Visit.

4. Males with a partner of childbearing potential must agree to use a barrier method
(condom) with a spermicide for the duration of treatment and for at least 48 hours
after discontinuing study drug.

Exclusion Criteria:

1. The subject is pregnant or lactating.

2. The subject was prematurely discontinued from Study RIN-PH-304.

3. The subject is intolerant to prostanoid therapy.

4. The subject is scheduled to receive another investigational drug, device, or therapy
during the course of this study.

5. Any other clinically significant illness or abnormal laboratory value(s) that, in the
opinion of the Investigator, might adversely affect the interpretation of the study
data.