The goal of this clinical trial is to learn if romiplostim N01 works to treat severe primary immune thrombocytopenia in adults. It will also learn about the safety of romiplostim N01. The main question it aims to answer is:

TO evaluate the effectiveness of the combination treatment of glucocorticoids, gamma globulin and romiplostim N01 in patients with severe primary immune thrombocytopenia during the initial treatment period for one month.

Participants will:

Romiplostim N01, starting dose of 1 µg/kg, subcutaneous injection, given on the third day of IVIG, once a week, for up to one month.

IVIG, 400mg/kg/d, intravenous administration, continuous administration for 3-5 days.

Prednisone, 0.8mg/kg/d, taken orally or intravenously, for up to one month.

Inclusion Criteria:

1. Participants must sign a written informed consent prior to enrollment;
2. Ages 18-75;
3. Platelet count <10×10^9/L with active bleeding or bleeding score ≥5;
4. No contraindications to the use of steroids, romiplostim, or IVIG, and willingness to receive these treatments;
5. No prior splenectomy or at least one first-line ITP treatment or emergency treatment;
6. No prior romiplostim treatment;
7. ECOG PS score: 0-2;
8. Female participants of childbearing potential must agree to use reliable contraception (including male or female condoms, contraceptive foam, contraceptive jelly, contraceptive patches, contraceptive cream, contraceptive suppositories, abstinence, and placement of intrauterine contraceptive devices) throughout the study; women who have had a hysterectomy, bilateral oophorectomy, bilateral salpingo-oophorectomy, or have been postmenopausal for more than 1 year, and men who have had bilateral vasectomy or vasectomy are excluded;
9. Voluntary participation in this study and good compliance.

Exclusion Criteria:

1. Individuals with the following hematological disorders other than ITP, including but not limited to leukemia, thrombocytopenia caused by cancer treatment, myeloproliferative diseases, multiple myeloma, and myelodysplastic syndrome;
2. Individuals with a history of thrombosis;
3. Pregnant or lactating individuals;
4. Individuals with severe cardiopulmonary insufficiency;
5. Individuals with severe or uncontrollable infections;
6. Individuals with viral infections;
7. Individuals who cannot comply due to psychological reasons;
8. Individuals who are deemed unsuitable for participation in the study by the investigator.