An Open-Label ProSpective MultiCENTer Study to Evaluate Safety and Tolerability of Dry Powder Inhaled Treprostinil in PH

Inclusion Criteria:

1. An Institutional Review Board (IRB) approved informed consent is signed and dated bythe subject prior to any study related activities.

2. Male or Females between 18 years to 75 years of age at Screening. Subjects between 76 and 80 years of age at Screening can be considered for eligibility but willrequire approval of the Sponsor's MM or designee.

3. If the subject is a female of childbearing potential, then the subject must have anegative pregnancy test result at the Baseline Visit and agrees to practice adequatebirth control throughout the duration of the study. If the subject is postmenopausalor has documented surgical sterilization, a pregnancy test and birth control are notnecessary. It is the Investigator's responsibility for determining whether thesubject has adequate birth control for study participation.

4. Has a confirmed diagnosis of WHO Group 3 PH-ILD based on CT chest imaging performedwithin 12 months prior to baseline visit, which demonstrates evidence of diffuseparenchymal lung disease and FEV1/FVC (absolute values) >70%. Subjects are requiredto have evidence of pulmonary hypertension (PH) as demonstrated from right heartcatheterization (RHC) within 6 months of the baseline visit with the followingdocumented parameters depending on their lung disease category a) or b). a. Subjects may have any form of ILD or combined pulmonary fibrosis and emphysema (CPFE). i) Pulmonary vascular resistance (PVR) > 3 Wood Units (WU) and ii) Pulmonarycapillary wedge pressure (PCWP) of < 15 mmHg and iii) A mean pulmonary arterialpressure (mPAP) of > 30 mmHg OR b. A exploratory subset of subjects with ILD: i) Pulmonary vascular resistance (PVR) > 3 Wood Units (WU) and ii) Pulmonary capillary wedge pressure (PCWP) of < 15mmHg and iii) A mean pulmonary arterial pressure (mPAP) of > 21 mmHg

5. Must be able to walk a distance of >125 meters on two six-minute walk tests (6MWTs)during the screening and baseline assessments. The variability of the distancesbetween the two qualifying 6MWTs must be within 15% of one another, calculated fromthe furthest walk.

6. Subjects on a chronic medication for underlying lung disease (i.e. pifenidone,nintedanib, etc) must be on a stable dose and regimen for > 30 days prior toBaseline and planned to continue for the duration of the study at the same dose.

7. Demonstrates the ability to use the RS00 Model 8 inhaler.

Exclusion Criteria:

A Subject is not eligible for inclusion in the study if any of the following criteria apply:

1. Pulmonary hypertension (PH) in the Updated WHO Classification Groups 1, 2, 4, or 5.

2. Intolerance or significant lack of efficacy to a prostacyclin or prostacyclinanalogue that resulted in discontinuation or inability to effectively titrate thattherapy.

3. Received any FDA approved PAH or PH-ILD prostacyclin therapy including:epoprostenol, treprostinil, iloprost, beraprost, or IP receptor agonist (selexipag),except for acute vasoreactivity testing within 60 days of Screening.

4. Received any FDA PAH approved oral therapy including: endothelin receptor antagonist (ERA), or soluble guanylate cyclase (sGC) stimulator within 60 days of Baseline.

• phosphodiesterase type 5 inhibitors (PDE5-I) are permitted if on a stable dosefor at least 60 days prior to the right heart catheterization and planned tocontinue for the duration of the study at the same dose.

• PDE5-I are permitted for erectile dysfunction as needed but should be withheldat least 48 hours prior to a scheduled visit.

5. New type of chronic therapy (including but not limited to oxygen, a different classof vasodilator, diuretic, digoxin, and digitalis) for pulmonary hypertension addedwithin 30 days of Screening and prior to Baseline.

6. Uncontrolled systemic hypertension as evidenced by persistent, systolic bloodpressure greater than 160 mmHg or diastolic blood pressure greater than 100 mmHg.

7. History of hemodynamically significant left-sided heart disease including, but notlimited to: aortic or mitral valvular disease more than mild, pericardialconstriction, restrictive or congestive cardiomyopathy with estimated leftventricular ejection fraction less than 40%, or symptomatic coronary artery disease (CAD).

8. Prior atrial septostomy.

9. Receiving > 8 L/min of oxygen supplementation by any mode of delivery at rest atScreening and prior to Baseline.

10. Serious or life-threatening disease other than conditions associated with PH or ILD.

11. Therapy with any excluded medications listed in the Investigator's Brochure.

12. Hypersensitivity or allergy to any of the ingredients of LIQ861 or other clinicallyrelevant allergies (clinical relevance per Investigator judgment).

13. Exacerbation of underlying lung disease or active pulmonary or upper respiratoryinfections within 30 days of Screening and prior to Baseline.

14. Current RT-PCR confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or recent history of lab confirmed SARS-CoV-2 infection inprevious 30 days of Screening and prior to Baseline.

15. ILD developed from a SARS-CoV-2 infection (ILD should have preceded infection).

16. Initiation of pulmonary rehabilitation within 12 weeks prior to Screening (participants who are stable in the maintenance phase of a program and who willcontinue for the first 16 weeks of the study are eligible).

17. In the opinion of the Investigator, the subject has any condition that wouldinterfere with the interpretation of study assessments or has any disease orcondition (i.e., peripheral vascular disease, musculoskeletal disorder, morbidobesity) that would likely be the primary limit to ambulation (as opposed to PH).

18. Acute pulmonary embolism within 90 days of Screening or prior to Baseline.

19. Stroke or transient ischemic attack (TIA) within six months of Screening or prior toBaseline.

20. Evidence of an active uncontrolled sepsis or systemic infection during Screening.

21. Pregnant, plans to become pregnant, or lactating.

22. Participated in an investigational drug or device study within the 30 days prior toScreening.

23. In the opinion of the Investigator, significant use of any inhaled tobacco/marijuanaproducts or significant recent history of drug abuse at the time of informedconsent.

24. Subject has severe hepatic impairment as evidenced by any history of ascites ANDencephalopathy.

25. Renal impairment (eGFR < 40). (Appendix 5).

26. Severe concomitant illness limiting life expectancy (≤ 6 months) or listed "active"for lung transplantation.

27. Currently on hospice status or planned hospice status in the next 6 months.

28. Known anaphylactoid reaction or hypersensitivity allergy to intravenous iodinatedcontrast media.