Ixekizumab is a medication used in this study to treat children with certain types of juvenile idiopathic arthritis, including enthesitis-related arthritis and juvenile psoriatic arthritis. It is given as an injection under the skin and works by targeting specific proteins in the body that cause inflammation, helping to reduce symptoms like joint pain and swelling.

Adalimumab is another medication used in this study as a reference treatment. It is also used to treat children with juvenile idiopathic arthritis. Adalimumab is administered through an injection and helps to decrease inflammation by blocking a protein in the body that contributes to the inflammatory process.

Juvenile Psoriatic Arthritis – This is a type of arthritis that affects children and is associated with psoriasis, a skin condition. It causes joint pain, swelling, and stiffness, often in the fingers and toes. Over time, it can lead to joint damage and changes in the nails, such as pitting or separation from the nail bed. The disease may also cause fatigue and affect the eyes, leading to inflammation. Symptoms can vary widely among individuals, with periods of flare-ups and remission.

Enthesitis Related Arthritis – This form of juvenile arthritis primarily affects the areas where tendons and ligaments attach to bones, known as entheses. It often leads to pain and swelling in the joints, particularly in the lower limbs, and can also affect the spine. The disease may cause stiffness, especially in the morning or after periods of inactivity. Over time, it can lead to reduced mobility and changes in posture. Enthesitis related arthritis is more common in boys and may be associated with other conditions like inflammatory bowel disease.