A Dose-escalation Study Followed by a Dose Optimal Study to Evaluate the Safety and Efficacy of CID-103 in Adults With Chronic Immune Thrombocytopenia

The goal of the global Phase 1/2 clinical trial is to evaluate whether CID-103, a novel anti-CD38 monoclonal antibody, is safe and effective in adults with chronic immune thrombocytopenia (ITP). The main questions the study aims to answer are: * To evaluate the safety and tolerability of CID-103 in subjects with ITP with different increasing doses of CID-103. * To further evaluate the safety and tolerability of CID-103 at two or three dose levels and to select an optimal dose and administration regimen for CID-103 for further study of clinical efficacy. The study will be done in two parts: Part A will test increasing doses of CID-103 to see how safe it is and how well people tolerate it. Researchers will also aim to find a safe dose range. Part B will compare up to three different doses of CID-103 to see how well the medicine works and gather more safety and efficacy information. The goal is to find the optimal dose to use in future studies. CID-103 is given through an intravenous (IV) infusion. During the study, participants may receive treatment for up to 6 months, followed by a post-treatment safety follow-up period to check for ongoing safety and effectiveness. This study is an important step toward developing a new treatment for people living with chronic ITP. If CID-103 is found to be safe and effective, it could offer a new option for patients who do not respond well to current therapies.