This is a prospective, single-arm, open-lable, single-center study and we aimed to determine whether atorvastatin combined with N-acetyl-L-cysteine (NAC) plus romiplostim could induce sustained response off-treatment (SRoT) in adult patients with ITP following CS failure.

This is a prospective, single-arm trial designed to investigate whether atorvastatin combined with N-acetyl-L-cysteine (NAC) plus romiplostim can induce a sustained response off-treatment (SRoT) in adult patients with immune thrombocytopenia (ITP) who experienced failure of first-line corticosteroid therapy. In this study, SRoT is defined as an off-treatment period during which the platelet count remains above 30×10⁹/L in the absence of bleeding events or rescue therapy. The primary endpoint was the proportion of patients who achieved SRoT by Week 24 after the discontinuation of romiplostim. From Week 1 to Week 24, atorvastatin and NAC was administrated as the dose of 20mg qd and 400mg tid,respectively, and were discontinued at the end of Week 24. During the initial 24 weeks, romiplostim was initiated at a starting dose of 3 μg/kg per week. The weekly dose was adjusted based on platelet counts, with a maximum dose of 10 μg/kg per week, to maintain platelet levels within the range of 100-200×10⁹/L. From Week 25 to Week 35, romiplostim was gradually tapered and discontinued, with the goal of maintaining a platelet count ≥30×10⁹/L and no less than twice the baseline level. After all medications (including atorvastatin, NAC, and romiplostim) were discontinued (no later than Week 36), patients were followed up for an additional 24 weeks to evaluate the sustained response rate at 24 weeks post-treatment cessation.

Inclusion Criteria:

• Diagnosed with primary ITP;
• Aged ≥18 years;
• Patients with treatment failure or relapse after first-line corticosteriod therapy for ITP;
• Platelet count <30×10⁹/L.

Exclusion Criteria:

• Pregnant or lactating women, and who were possibly pregnant, planning to become pregnant, or who had partners planning to become pregnant;
• Presence of active malignant tumors;
• Active HBV, HCV or HIV infection;
• Active infection requiring systematic treatment;
• Leukemia, myelodysplastic syndrome, aplastic anemia, myelofibrosis or other hematological disorders that may cause thrombocytopenia;
• History or presence of myocardial infarction, unstable ischemic heart disease, stroke, or NYHA Class IV heart failure;
• AST > 2 times the upper limit of normal (ULN), ALT > 2×ULN, or TBIL ≥ 1.5×ULN;
• eGFR < 50 mL/min/1.73m²;
• Any other subjects deemed ineligible for enrollment by the investigator.