This clinical trial is focused on studying a condition known as Diffuse Cutaneous Systemic Sclerosis, a rare disease that causes the skin and other organs to become thick and hard. The trial will use a medication called Fipaxalparant, also known by its code name HZN-825. This medication is taken in the form of a tablet and works as a selective antagonist of a receptor called LPAR1, which is involved in the disease process.

The purpose of the study is to evaluate how effective, safe, and tolerable HZN-825 is for patients with Diffuse Cutaneous Systemic Sclerosis. Participants in this study will take the medication twice a day for a period of 52 weeks. This study is an extension of a previous trial, meaning it continues the research from an earlier phase to gather more information about the medication’s effects over a longer period.

Throughout the study, participants will be monitored to see how their condition changes, particularly looking at lung function and physical abilities. The study aims to provide valuable insights into the potential benefits and any side effects of using HZN-825 for treating Diffuse Cutaneous Systemic Sclerosis.