The purpose of this study is to measure clinical safety and efficacy of oral brepocitinib in adult participants with cutaneous sarcoidosis.

The study will test OATD-01, an experimental medicine, for the first time in patients with pulmonary sarcoidosis (swollen tissue in the lungs). The study goal is to evaluate OATD-01 in the reduction of inflammation and assessing OATD-01 safety.

Everyone who participates in this study will receive OATD-01 or matching placebo (inactive mock tablet). Subjects will be randomly assigned to receive either OATD-01 or placebo for 12 weeks.

The study will run in several hospitals or outpatient clinics, in different countries in Europe and in the USA. In this study, there will be about 98 study subjects in total.

For all patients whether taking OATD-01 or matching placebo, there will be a screening period, a treatment period which will commence after randomization has taken place and will last for 12 weeks and then a follow up visit approximately 4 weeks post last dose of OATD-01.

The total duration of the study is 18 weeks.

This research study aims to determine a less invasive way to assess heart function by taking measurements of the heart while subjects are performing an exercise cardiac MRI. Subjects will undergo two exercise phases and MRI measurements will be taken after each exercise phase. These measurements will be compared to available clinical data (including demographic, hemodynamic, radiologic, and functional) and future outcome data.

The purpose of the study is to generate a bio bank of specimens for research. We will tissue that would otherwise be discarded from clinical or surgical procedure and information from medical records. We will also collect discarded blood, urines and sputum. Collecting samples will help to better understanding the mechanisms of cardiovascular diseases, identify biomarkers for early diagnosis and to predict safety and efficacy of new therapies.

You are being asked to take part in this research study because you have been diagnosed with pulmonary sarcoidosis. Sarcoidosis is a disease that can affect the lungs, skin and other organs of the body. Sarcoidosis also involves immune cells which fight bacteria. The purpose of this study is to see if using specific antibiotics will help these immune fighting cells get rid of bacterial proteins and how the antibiotics affect respiratory (breathing) function. The antibiotics used in this study are Levaquin, Ethambutol, Azithromycin, and either Rifampin or Rifabutin. You will by chance be assigned either these medicines or a placebo (an inactive substance).

The purpose of this study is to create and maintain a registry, which is a database (a searchable collection of information) about children, adolescents and young adults with pediatric onset of rheumatic diseases. This data may help in the evaluation of the safety and benefit of medications that are prescribed to patients who have rheumatic diseases.