• Voluntary and signed informed consent, good compliance.

• Age: 18 or above (when signing the informed consent form); Eastern Cooperative Oncology Group (ECOG) performance status (PS) score of 0 or 2; Life expectancy ≥ 24 weeks.

• Patients diagnosed with Primary myelofibrosis (PMF), post polycythemia vera myelofibrosis (post PV MF), or post essential thrombocythemia myelofibrosis (post ET MF)

• According to the dynamic international prognostic scoring system (DIPSS), patients with intermediate or high risk of bone marrow fibrosis were evaluated.

• Within 7 days before the first administration, the symptom score of myeloproliferative neoplasms should meet certain requirements.

• Patients with poor efficacy of JAK inhibitors (for phase Ib and phase II cohort 2, cohort 3)

• Patients who had not received JAK inhibitor treatment (for phase II cohort 1).

• Spleen enlargement.

• Peripheral blood primary cells and bone marrow primary cells were ≤10%.

• No growth factor, colony stimulating factor, thrombopoietin or platelet transfusion was received within 2 weeks before the examination, and the blood routine indexes met the requirements within 7 days before the first administration.

• The Main organ function is normal.

• Men and women of childbearing age should agree to use contraceptive measures (such as intrauterine devices, contraceptives, or condoms) during the study period and within 6 months after the end of the study. Serum human chorionic gonadotrophin (HCG) test is not negative within 7 days before the first administration and must be non-lactating patients.