• The patients have provided written informed consent prior to enrollment.

• Men and women greater than or equal to 18 years of age.

• Diagnosed as ITP secondary to connective tissue diseases (including but not limited to systemic lupus erythematosus, Sjogren's syndrome and rheumatoid arthritis), primary ITP with positive antinuclear antibody but not up to the diagnostic criteria of connective tissue diseases, primary Evans syndrome, Evans syndrome secondary to connective tissue diseases, and primary ITP with positive Coomb's test but not up to the diagnostic criteria of Evans syndrome.

• Platelet count\<30 ×10\^9/L at screening.

• Patients who have previously failed to receive Eltrombopag or Herombopag \[poor efficacy (Eltrombopag 75 mg/d or Herombopag 7.5 mg/D, at least 4 weeks), or the efficacy cannot be maintained\], or who have contraindications, can not tolerate or refuse Eltrombopag or Herombopag treatment.

• Treatment for ITP (including but not limited to glucocorticoids, recombinant human thrombopoietin, and other thrombopoietin receptor agonists other than Avatrombopag) must be completed before enrollment, or the dose must be stable or in a phase of reduction within 2 weeks before enrollment.

• Effective contraceptive measures will be taken during the clinical trial.