Clinical Research Directory

Inclusion Criteria: * 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. Exclusion Criteria: * Patients who have previously received allogeneic stem cell transplantation, or received autologous stem cell transplantation within 3 months before the first administration, or recently planned stem cell transplantation; * Previous treatment with BET inhibitors combined with JAK inhibitor; * Patients who have previously undergone splenectomy, or received splenic radiotherapy within 6 months before the first administration; * Use of any MF medications, any immunomodulators, any immunosuppressive agents, within 2 weeks prior to first administration (There are separate withdrawal requirements for hydroxyurea, JAK inhibitors, androgen drugs, erythropoietin, long-acting recombinant interferon-α, etc.); * Other malignancies within 3 years prior to first administration or currently present. * Patients with multiple factors (such as inability to swallow, postoperative gastrointestinal resection, acute and chronic diarrhea, intestinal obstruction, etc.) affecting oral or absorption of drugs; * Major surgical treatment or significant traumatic injury within 4 weeks prior to first administration; * Presence of congenital bleeding disorder and congenital coagulopathy; * Patients who had arterial/venous thrombosis events within 6 months before the first administration. * Have a history of mental drug abuse, or have a mental disorder. * Active or uncontrolled severe infection; * Active hepatitis B virus (HBV) infection, or hepatitis C virus (HCV) infection and HCV RNA positive, or active Corona Virus Disease 2019 (COVID-19) infection; * Patients with grade III or above congestive heart failure, unstable angina pectoris or myocardial infarction, or arrhythmia requiring treatment, or QT interval prolongation within 6 months before the first administration; * Unsatisfactory blood pressure control despite standard therapy; * Patients with renal failure requiring hemodialysis or peritoneal dialysis; * Patients newly diagnosed with pulmonary interstitial fibrosis or drug-related interstitial lung disease within 3 months before the first administration; * Patients with a history of immunodeficiency disease or organ transplantation; * Patients with epilepsy requiring treatment; * Patients who have received Chinese patent medicines with anti-tumor indications specified in the approved drug package insert of China National Medical Products Administration (NMPA) within 2 weeks before the first administration; * Patients with uncontrolled pleural effusion, pericardial effusion or ascites; * There was a history of attenuated live vaccine inoculation within 4 weeks before the first administration, or attenuated live vaccine inoculation was planned during the study period. * People with known hypersensitivity to the study drug and excipients; * Patients diagnosed as active autoimmune diseases within 2 years before the first administration; * Those who participated in and used other anti-tumor clinical trial drugs within 4 weeks before the first administration (except JAK inhibitor-related clinical trials). * According to the judgment of the investigators, some situations seriously endanger the safety of the subjects or affect the subjects to complete the study.