Multi-target Drugs Sequential Combination Therapy in Adults Patients With Newly Diagnosed Primary Immune Thrombocytopenia

The study will be conducted in three phases.

Phase 1. Core treatment phase includes initial treatment and sequential combination therapy (12 weeks, weeks 1-12):

Patients will receive standard-dose methylprednisolone or prednisone in combination with a thrombopoietin receptor agonist (TPO-RA) as initial therapy.Corticosteroids will be tapered and discontinued within 8 weeks; tapering will begin immediately in patients who achieve complete response (CR) and will also be initiated after 4 weeks in patients who do not achieve response (R). TPO-RA therapy will continue for 12 weeks, with dose adjustments made according to the approved prescribing information. Patients with treatment failure( defined as platelet count < 30 × 10^9/L or less than 2-fold increase of baseline platelet count or bleeding) after 2 weeks of initial therapy (Weeks 3-12) will receive the ongoing TPO-RA in combination with either rituximab or an anti-CD38 monoclonal antibody as sequential combination therapy.

Phase 2. Core-treatment follow-up and exploratory treatment phase (24weeks, weeks 13-36):

During the core treatment follow-up phase, patients with treatment failure will enter the exploratory treatment phase. Patients who did not receive rituximab or anti-CD38 monoclonal antibody during the core treatment phase will receive a switched TPO-RA combined with either rituximab or anti-CD38 monoclonal antibody, whereas patients who received either rituximab or anti-CD38 monoclonal antibody during the core phase will receive a switched TPO-RA combined with cross-administered rituximab and anti-CD38 monoclonal antibody.TPO-RA therapy will also continue for 12 weeks.

Phase3. Safety follow-up phase (4weeks,weeks 37-40).

Rescue therapy includes, but is not limited to, intravenous immunoglobulin (IVIG), platelet transfusion, and vindesine. A switch to another thrombopoietin receptor agonist (TPO-RA) will be considered rescue therapy during the core treatment period. Administration of recombinant human thrombopoietin (rhTPO) will also be considered rescue therapy.

Inclusion criteria

• Age ≥18 years.
• Confirmed newly diagnosed primary ITP with a platelet count <30 × 10^9/L.
• No prior ITP-related treatment before enrollment, except for standard-dose corticosteroids and/or IVIG for ≤5 days.
• Able to understand the study and provide signed informed consent.-

Exclusion criteria

• Use of corticosteroids or immunosuppressants for a non-ITP condition within 3 months.
• Contraindication to corticosteroid therapy.
• Arterial or venous thromboembolic event within 3 months.
• Pregnant or breastfeeding women.
• Current treatment with another investigational drug.
• Any other medical history or condition that, in the investigator's judgment, makes the participant unsuitable for the study.

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