This clinical trial is focused on studying the effects of two medications, Ustekinumab and Guselkumab, in children and teenagers with Juvenile Psoriatic Arthritis. Juvenile Psoriatic Arthritis is a type of arthritis that affects children and is associated with the skin condition psoriasis, which causes red, scaly patches on the skin. The purpose of the study is to evaluate how well these medications work, how safe they are, and how the body processes them when given as an injection under the skin.

Participants in the study will receive either Ustekinumab or Guselkumab over a period of up to 52 weeks. The study will monitor the participants’ response to the treatment, including any changes in their arthritis symptoms and any side effects they may experience. The study will also look at how the body absorbs and breaks down the medications, which is known as pharmacokinetics. This information will help determine the best dosage and frequency for these medications in treating Juvenile Psoriatic Arthritis.

Throughout the study, participants will have regular check-ups to assess their health and the effectiveness of the treatment. The study aims to provide valuable information on the use of Ustekinumab and Guselkumab in young patients with Juvenile Psoriatic Arthritis, potentially leading to better treatment options for managing this condition. The study will also gather data on the immune response to these medications, which is important for understanding their long-term safety and effectiveness.