Baricitinib is a medication that helps reduce inflammation in the body. It belongs to a class of drugs called JAK inhibitors, which work by decreasing the activity of the immune system. In this trial, it’s being studied for treating polymyalgia rheumatica, a condition that causes muscle pain and stiffness.

Prednisone and Prednisolone are corticosteroid medications (also known as GCs or glucocorticoids) that help reduce inflammation and suppress the immune system. These medications are commonly used to treat various inflammatory conditions, including polymyalgia rheumatica. In this trial, they are being used as a short-term treatment alongside either baricitinib or placebo.

Polymyalgia Rheumatica (PMR) – A chronic inflammatory condition that causes muscle pain and stiffness, primarily affecting the shoulders, neck, and hips. The condition typically develops gradually over several weeks and is characterized by morning stiffness that may last for hours. People with PMR often experience pain and limited range of motion in their upper arms, shoulders, neck, hips, and thighs. The condition most commonly affects people over the age of 50, and women are more likely to develop it than men. The symptoms tend to be worse in the morning or after periods of inactivity.