Safety and Efficacy of GL-2045 in Patients With Immune Thrombocytopenia

This is a Phase 1b, open-label, multiple subcutaneous (SC) injection dose study in participants with ITP. The specific aims of this study are to determine: * The safety of the study drug when given to participants with ITP * The effect of the study drug on safety blood tests and blood platelet counts * How the study drug affects certain responses in the body such as severity of bleeding, levels of fatigue and health-related quality of life * How much of the study drug gets into the bloodstream * The body's immune response to the study drug This information, together with pharmacokinetic (PK) data, will help to establish doses and dosing regimens suitable for use in future studies. The effects of GL-2045 on multiple biomarkers will also be investigated.