This clinical trial is focused on studying a condition known as Immune Thrombocytopenia (ITP). ITP is a disorder where the immune system mistakenly attacks and destroys platelets, which are cells in the blood that help with clotting. This can lead to easy or excessive bruising and bleeding. The treatment being investigated in this study is a medication called Rilzabrutinib, which is taken orally in the form of a tablet. Rilzabrutinib is a type of drug known as a BTK inhibitor, which means it works by blocking a specific protein in the body that is involved in the immune response.

The purpose of the study is to explore the safety and effectiveness of Rilzabrutinib in adults with ITP who have not responded well to previous treatments. The study is divided into two parts. In the first part, different doses of Rilzabrutinib will be tested to find the most suitable dose. In the second part, the focus will be on a specific dose to see how well it works over a longer period. Participants will take the medication and have regular check-ups to monitor their platelet levels and any side effects they might experience.

Throughout the study, researchers will pay close attention to how the participants’ platelet counts change and whether they experience any side effects from the medication. The goal is to determine if Rilzabrutinib can help increase platelet counts and reduce bleeding symptoms in people with ITP. Participants will be monitored closely to ensure their safety and to gather information on how well the treatment works over time.