Study to Evaluate Safety and Efficacy of Mirivadelgat in PH-ILD

Inclusion Criteria:

1. A clinical diagnosis of PH-ILD.

2. Subject voluntarily gives informed consent.

3. Subjects aged between 18 and 85 years at the time of signing informed consent.

4. Subjects must agree to practice protocol-defined birth control during the studyperiod.

• Males with a partner of childbearing potential must practice protocol-definedbirth control for the duration of treatment and at least 96 hours afterdiscontinuing the IP.

• Female subjects of childbearing of potential (including those <1-year postmenopausal) must practice protocol-defined birth control during the conduct ofthe study and for 30 days after the last dose of IP (males only during exposureto IP).

• Women not of childbearing potential are defined as:

1. Post-menopausal women (at least 12 months with no menses without analternative medical cause); in women <45 years of age, a highfollicle-stimulating hormone (FSH) level in the post-menopausal range maybe used to confirm a post-menopausal state in women not using hormonalcontraception or hormonal replacement therapy; OR

2. Have had a hysterectomy and/or bilateral oophorectomy, bilateralsalpingectomy, or bilateral tubal ligation/occlusion, at least 6 weeksprior to screening; OR

3. Have a congenital or acquired condition that prevents childbearing.

4. The subject has a confirmed diagnosis of any form of interstitial lung disease basedon high resolution computed tomography (HRCT) of the chest within 180 days prior toscreening or at screening or a historical surgical biopsy (or other appropriatetissue sampling (e.g., cryobiopsy). The subject can have other findings (e.g.,emphysema) if this is not the predominant feature on the scan.

5. Subjects have undergone RHC during the screening period with the followingdocumented parameters:

• Pulmonary vascular resistance (PVR) ≥4 Wood units and

• Pulmonary capillary wedge pressure (PCWP) of ≤12 mmHg [if PVR ≥4 Wood units to <6.25 Wood units] or PCWP ≤15 mmHg [if PVR ≥6.25 Wood units] (a leftventricular end diastolic pressure [LVEDP] will be acceptable if a reliablePCWP cannot be obtained) and

• A mean pulmonary arterial pressure (PAP) of >20 mmHg.

7. Subjects must have a baseline 6-minute walk distance ≥100 meters and ≤500 meters.

8. Subjects agree to a repeat RHC, Chest CT, and MRI prior to study completion.

9. Subjects on chronic treatment for underlying lung disease (i.e., nintedanib orpirfenidone or immunosuppressive agents etc.) must be on a stable/optimized dose for ≥30 days prior to screening and have been receiving treatment for ≥90 days.

10. Subjects on supportive medications (e.g., inhalers for asthma) must be on stabledoses for ≥30 days prior to screening.

11. In the Investigator's opinion, the subject must be able to consent for themselvesand communicate with local staff using interpreters if necessary. Subjects mustagree to attend all study visits and be contactable through a cellular device orlandline.

12. Subjects must have clinical laboratory values within normal ranges or <1.5 times theupper limit of normal (ULN) as specified by the testing laboratory.

13. Pulmonary function test (PFT) showing a percent predicted forced vital capacity (FVC) <70% of predicted and diffusion capacity of carbon monoxide (DLCO) <70%corrected for hemoglobin (Hb) value ≥25% and ≤90% at screening (DLCO determinedlocally must be <70%) using the American Thoracic Society (ATS) standards.

14. Subjects with a prior diagnosis of connective tissue diseases, specifically systemicsclerosis (scleroderma), systemic lupus erythematosus, Sjogren's disease,polymyositis/dermatomyositis/antisynthetase syndrome, rheumatoid arthritis can beincluded in the study, but no more than 20% of total subjects.

15. Negative serology test for hepatitis B surface antigen and hepatitis C antibody atScreening Visit.

Exclusion Criteria:

Medical Conditions

1. Subject has another concomitant diagnosis of pulmonary hypertension not otherwiseconsidered to be PH-ILD. This would include and is not limited to the concomitantpresence of thromboembolic disease, untreated/inadequately treated obstructive sleepapnea, human immunodeficiency virus (HIV), methamphetamine or anorexigenic drug use,and other conditions of the WHO Group 1, 2, 4, and 5 classifications.

2. Subject has evidence of clinically significant left-sided heart disease within 6months as defined by:

• Left ventricular ejection fraction <40% as assessed by echocardiography.

• More than mild left-sided valvulopathy (e.g., worse than mild mitral stenosisor regurgitation and worse than mild aortic stenosis or regurgitation).

• LVEDP or PCWP >15 mmHg (or >12 mmHg if PVR ≥4 to 6.25 Wood units).

3. Subjects must NOT have 3 or more of the following left ventriculardisease/dysfunction risk factors at screening:

• Body mass index (BMI) ≥30 kg/m2.

• Uncontrolled diabetes, HbA1C >9.5%, urine glycosuria >1.0 g/dl, or presence ofdiabetic ketoacidosis

• History of significant coronary disease within 6 months of screening asdemonstrated by any of the following:

1. History of myocardial infarction or acute coronary syndrome (unstableangina), or

2. Percutaneous coronary intervention or percutaneous transluminalangioplasty, or previous coronary artery bypass graft, or

3. Evidence of coronary artery disease (>50% stenosis in at least one majorcoronary artery) or abnormal nuclear stress test.

4. The subject is receiving >10 L/min of oxygen supplementation by any mode of deliveryat rest.

5. The subject has received any PH-approved therapy, including phosphodiesterase type 5inhibitor, soluble guanylate cyclase inhibitor, endothelin receptor antagonist, orparenteral or oral prostacyclin therapy (excluding vasoreactivity testing) within 60days of randomization or 5 half-lives. Inhaled prostacyclin (e.g., inhaledtreprostinil) on stable doses for ≥30 days prior to screening will be allowedirrespective of local approval (as per ESC/ERS 2022).

6. Use of any potent inhibitors and potent inducers of cytochrome P450 3A4 (CYP3A4) (e.g., boceprevir, cobicistat, danoprevir and ritonavir, elvitegravir and ritonavir,grapefruit juice, indinavir and ritonavir, itraconazole, ketoconazole, lopinavir andritonavir, paritaprevir and ritonavir and (ombitasvir and/or dasabuvir),posaconazole, ritonavir, saquinavir and ritonavir, telaprevir, tipranavir andritonavir, telithromycin, troleandomycin, voriconazole, clarithromycin, idelalisib,nefazodone, nelfinavir, carbamazepine, enzalutamide, mitotane, phenytoin, rifampin,St. John's wort).

7. Recent exacerbation of underlying lung disease or active pulmonary/upper respiratorytract infection within 4 weeks of randomization.

8. Any current active malignancy (this does not include localized cancers such as basalor squamous cell carcinoma of the skin). Any history of malignancy that is likely toresult in mortality or require significant medical or surgical intervention withinthe following year.

9. Chronic kidney disease Stage IV or greater (i.e., eGFR ˂30 mL/min/1.73m2) orevidence of acute kidney injury.

10. The subject has a history of congenital heart disease irrespective of any priortreatment of surgical intervention

11. Use of tobacco, e-cigarette, nicotine, or marijuana products or significant historyof drug or alcohol abuse within 6 months of screening.

12. Acute pulmonary embolism within 90 days of screening.

13. Participation in pulmonary rehabilitation within 90 days of screening.

14. Prior or concurrent use of any investigation drug/device/therapy or participation inany investigational study with therapeutic intent within 30 days or 5 half-lives,whichever is longer before the first dose of the IP.

15. BMI ≥40 kg/m2.

16. Uncontrolled hypertension as evidenced by systolic blood pressure >160 mmHg ordiastolic blood pressure >100 mmHg during the screening period. Subjects who failscreening due to high blood pressure can be re-screened once, after theirantihypertensive medicines have been adjusted and doses have been stable for atleast 4 weeks.

17. Concomitant disease that confers a life expectancy of <6 months at screening.

18. The Investigator judges that the subject will be unable to fully participate in thestudy and complete it for any reason, including inability to comply with the studyprocedures and treatment of addiction or any other relevant medical or psychiatricconditions.

19. High likelihood of lung transplantation (in the opinion of the Investigator) within 4 months after randomization.

20. History of liver dysfunction, including subjects with moderate (Child-Pugh B) orsevere (Child Pugh C) impairment or disordered coagulation.

21. Female subjects who are pregnant or breastfeeding.

22. Worse than mild untreated sleep apnea (5-14.9 events/hour). Treated sleep apnea ispermitted. Other Exclusions

23. History of allergic or anaphylactic reaction to mirivadelgat or to any component ofthe excipient.

24. Previous exposure to mirivadelgat. Diagnostic Assessments

25. The following laboratory parameters are excluded:

• Hemoglobin <10 g/dL (100 g/L).

• White blood cells (WBC) <3000/µL (<3000/mm3).

• Platelet count <70,000/µL (70,000/mm3).

• Estimated glomerular filtration rate (eGFR) <30 mL/min/1.73m2 or evidence ofacute kidney injury.