Participant must be ≥ 18 years of age at the time of signing the informed consent
Participants must have a diagnosis of World Health Organization Group 1 Pulmonary Hypertension (PH) (PAH) with the following characteristics
Etiology of idiopathic, heritable, drug/toxin-induced or connective tissue disease (CTD)-related PAH
Right heart catheterization with the following hemodynamic findings
Mean pulmonary arterial pressure (mPAP) > 20 mmHg at rest
No change in diuretic use or dosage for at least 30 days prior to Screening
Pulmonary capillary wedge pressure (PCWP) ≤ 15 mmHg, and
Pulmonary vascular resistance (PVR) of ≥ 3 Wood Units (WU)
Male participants: Male participants and their female partners of childbearing potential must agree to use highly effective contraception from Study Day 1 to at least 90 days after dosing
No change in pulmonary hypertension medications (eg, ambrisentan, bosentan, macitentan, sildenafil, tadalafil, riociguat) or dosage for at least 90 days prior to Screening
Female participants: Women of child-bearing potential (WOCPB, defined as premenopausal, not surgically sterile for at least 3 months prior to Screening) must use a highly effective contraception method and agree to be tested for pregnancy from at Screening, Baseline, and 30 days after dosing
Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in the protocol
Body mass index (BMI) within the range 18.0 - 32.0 kg/m^2 (inclusive)
Any PH other than idiopathic, hereditary, drug/toxin-induced, or connective tissue disease (CTD) associated PAH (eg, congenital heart disease-associated PAH, portal hypertension-associated PAH, PH belonging to Groups 2 through 5)
Allergy, or documented hypersensitivity or contraindication, to the ingredients of treprostinil palmitil inhalation powder (TPIP) or treprostinil (TRE)
Previous intolerance to prostacyclin analogs or receptor agonists (eg, selexipag) per investigator discretion
History of anaphylaxis or previously documented hypersensitivity reaction to any drug per Investigator discretion
History of heart disease including left ventricular ejection fraction (LVEF) ≤ 40% or clinically significant valvular, constrictive, or atherosclerotic heart disease (myocardial infarction, etc)
History of HIV infection/positive HIV serology test result at Screening
History of active/chronic Hepatitis B or C/ positive hepatitis B or C serology test result at Screening
Active liver disease or hepatic dysfunction manifested as
History of abnormal bleeding or bruising
Elevated liver function test results (ALT or AST > 2 × ULN) at Screening
Known or suspected immunodeficiency disorder, including history of invasive opportunistic infections (eg, tuberculosis, histoplasmosis, listeriosis, coccidioidomycosis, pneumocystosis, aspergillosis) despite infection resolution, or otherwise recurrent infections of abnormal frequency, or prolonged infections suggesting an immune-compromised status, as judged by the investigator
Yes for Known or suspected immunodeficiency disorder, including history of invasive opportunistic infections (eg, tuberculosis, histoplasmosis, listeriosis, coccidioidomycosis, pneumocystosis, aspergillosis) despite infection resolution, or otherwise recurrent infections of abnormal frequency, or prolonged infections suggesting an immune-compromised status, as judged by the investigator exclusion criteria 11
No for Known or suspected immunodeficiency disorder, including history of invasive opportunistic infections (eg, tuberculosis, histoplasmosis, listeriosis, coccidioidomycosis, pneumocystosis, aspergillosis) despite infection resolution, or otherwise recurrent infections of abnormal frequency, or prolonged infections suggesting an immune-compromised status, as judged by the investigator exclusion criteria 11
Not sure for Known or suspected immunodeficiency disorder, including history of invasive opportunistic infections (eg, tuberculosis, histoplasmosis, listeriosis, coccidioidomycosis, pneumocystosis, aspergillosis) despite infection resolution, or otherwise recurrent infections of abnormal frequency, or prolonged infections suggesting an immune-compromised status, as judged by the investigator exclusion criteria 11
Bilirubin > 1.5 × ULN (isolated bilirubin > 1.5 × ULN; ULN is acceptable if bilirubin is fractionated and direct bilirubin < 35%) at Screening
Active and current symptomatic infection by SARS CoV 2
Known hepatic or biliary abnormalities, not including Gilbert's syndrome or asymptomatic gallstones at Screening
Participants with current or recent (past 4 weeks) lower respiratory tract infection
History of malignancy in the past 5 years, with exception of completely treated in situ carcinoma of the cervix and completely treated non-metastatic squamous or basal cell carcinoma of the skin
Participants receiving triple combination therapy for PAH consisting of endothelin receptor agonists, phosphoesterase type 5 inhibitors, and guanylate cyclase stimulators (riociguat)
Participants receiving prostanoids/prostacyclin agonists
Participants receiving potent CYP2C8 inhibitors, such as gemfibrozil
Have participated in any other interventional clinical studies within 30 days of Baseline
Current or history of substance and/or alcohol abuse
Current user of cigarettes or e-cigarettes
Pregnant or breastfeeding