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

The goal of this clinical trial is to see if mirivadelgat will work in participants with Pulmonary Hypertension Associated with Interstitial Lung Disease (PH-ILD). It will also learn about the safety of mirivadelgat. The main question it aims to answer is if mirivadelgat will improve pulmonary vascular resistance (PVR). Pulmonary vascular resistance is a way to measure blood flow in the lungs. Researchers will compare mirivadelgat to a placebo (a look-alike capsule that contains no drug) to see if mirivadelgat works to improve the symptoms of PH-ILD. The symptoms of PH-ILD that are being looked at are exercise tolerance, heart function, and general well-being. Participants will: Take mirivadelgat or a placebo once a day for 12 weeks Visit the clinic once every 4 weeks for checkups and tests Receive phone calls every one or two weeks to check on how things are going

Inclusion Criteria: 1. A clinical diagnosis of PH-ILD. 2. Participant voluntarily gives informed consent. 3. Male or female participants aged between 18 and 85 years at the time of signing informed consent. 4. Participants must agree to practice protocol-defined birth control during the study period, unless they meet criteria for not being of childbearing potential. * Male participants with female partners of childbearing potential must practice protocol- defined birth control for the duration of treatment and at least 96 hours after discontinuing the IP. * Female participants of childbearing of potential (including those \