Avatrombopag in the Treatment of Primary Immune Thrombocytopenia(ITP)

Inclusion Criteria:

1. Aged 18+ years, male or female;
2. Ever been diagnosed as ITP patients. The diagnostic criteria comply with the "ChineseGuidelines for the Diagnosis and Treatment of Adult Primary Immune Thrombocytopenia (2020 Edition)"
3. At least 2 consecutive blood tests showed a decrease in platelet count; noobvious abnormality in the morphology of blood cells by peripheral blood smearmicroscopy.
4. Spleen is generally not enlarged.
5. Bone marrow examination: the morphological characteristics of bone marrow cellsin ITP patients were increased or normal megakaryocytes with maturationdisorders.
6. Other secondary thrombocytopenia must be excluded: autoimmune diseases, thyroiddisease, lymphoproliferative disorders, myelodysplastic syndrome (MDS), aplasticanemia (AA), various malignant hematologic diseases, tumor infiltration, Chronicliver disease, hypersplenism, common variant immunodeficiency disease (CVID),infection, vaccination causing secondary thrombocytopenia; Thrombocytopenia dueto depletion; Drug induced thrombocytopenia; Alloimmune thrombocytopenia;Thrombocytopenia during pregnancy; Congenital thrombocytopenia andpseudo-thrombocytopenia;
7. ECOG general status score ≤ 2;
8. Platelet count < 30×10^9/L；platelet count ≥< 30×10^9/L accompanied by active bleeding;If the platelet count is around 30×10^9/L and no active bleeding, a second examinationmust be performed to further confirm the platelet count.
9. Voluntarily signed the informed consent.
10. Any other circumstances that the investigator considers appropriate for the patient toparticipate in the study.

Exclusion Criteria:

1. Patients with secondary thrombocytopenia.
2. Currently receiving other TPO-RAs, rhIL-11 and rhTPO treatment, and subjects areunwilling to switch to avatrombopag treatment.
3. Patients with severe insufficiency of heart, lung, liver and kidney.
4. Pregnant or breast-feeding, or contraceptive measures cannot be taken during thetrial.
5. Subjects participated in clinical studies of other investigational drugs or deviceswithin 30 days prior to screening.
6. Having a history of psychotropic drug abuse and unable to quit or having mentaldisorders.
7. Having significant factors that affect the absorption of oral drugs, such as inabilityto swallow, chronic diarrhea and intestinal obstruction, etc.
8. Subject is allergic to avatrombopag or any of its excipients;
9. Any other circumstances that the investigator considers inappropriate for the patientto participate in the study.