A Clinical Trial of Flonoltinib Maleate for Intermediate or High-Risk Myelofibrosis

Inclusion Criteria: 1. Age range of 18-80 years old , gender not limited; 2. Patients diagnosed with primary myelofibrosis (PMF) according to WHO criteria (2016 edition) or patients diagnosed with post polycythemia vera myelofibrosis (PPV-MF) or post thrombocytopenia myelofibrosis (PET-MF) according to IWG-MRT criteria; 3. Expected survival period greater than 24 weeks; 4. ECOG score 0-2 points; 5. Splenomegaly: Palpation of the splenic margin reaching or exceeding 5cm below the rib ; Or due to physical reasons (such as obesity), it may not be palpable, but MRI/CT spleen evaluation during screening confirms a volume of \>= 450 cm\^3; 6. Within 7 days prior to randomization, the main organ functions were generally normal, meeting the following criteria: ALT and AST \<= 2.5 × ULN; TBIL\<=2.0×ULN； Serum creatinine \<=1.5 × ULN or serum creatinine clearance rate (Ccr)\>50 mL/min; INR, PT, and APTT \<= 1.5 × ULN; 7. Can understand and voluntarily sign an informed consent form. Exclusion Criteria: 1. The toxic reactions of previous anti-cancer treatments have not recovered to grade 1 or below (excluding hair loss), or have not fully recovered from previous surgeries; 2. Allergy to experimental drugs and their excipients; 3. For any significant clinical and laboratory abnormalities, the researchers believe that they affect the safety evaluators, such as: a. uncontrollable diabetes - fasting blood glucose\>250 mg/dL (13.9 mmol/L), b. hypertension and cannot be reduced to the following range after treatment with two or more antihypertensive drugs (systolic blood pressure\<160 mmHg, diastolic blood pressure\<100 mmHg), c. peripheral neuropathy; 4. Patients with a history of congestive heart failure (NYHA grade III or above), unstable angina or myocardial infarction, cerebrovascular accidents or thromboembolism within the first 6 months of screening; 5. Individuals with impaired cardiac function (those with ejection fraction\<45% detected by echocardiography, congenital ventricular arrhythmia, QTcF\>450 ms on electrocardiogram (males), QTcF\>470 ms on electrocardiogram (females), or those with arrhythmia requiring treatment at the time of screening); 6. Patients with congenital or acquired bleeding disorders or unstable thrombotic diseases requiring anticoagulant therapy; 7. Any active infection requiring systemic treatment (oral, intravenous, subcutaneous, intramuscular, etc.) within the first 14 days of randomization; 8. Active infection of hepatitis B virus (HBV) or hepatitis C virus (HCV), except for the following patients: a) HBV infection: patients who are positive for hepatitis B surface antigen (HBsAg) or hepatitis B core antibody (HBcAb) and undergo peripheral blood HBV-DNA testing, with the lower limit of HBV-DNA detection value (i.e. the upper limit of normal value in the laboratory of each research center) can be enrolled; If the baseline HBsAg is positive, continuous antiviral treatment is required after enrollment, and HBV-DNA testing should be conducted every 12 weeks and at EOT visits; b) Patients who are positive for HCV serology but negative for HCV-RNA can be included in the study; 9. Patients who are positive for human immunodeficiency virus antibodies (HIV Ab) or anti Treponema pallidum antibodies (TP Ab) (Treponema pallidum antibodies positive); 10. Patients with epilepsy or those taking psychotropic or sedative drugs during screening; 11. Pregnant or lactating female patients, female/male patients with fertility who refuse to use contraceptive measures during the trial period and within 6 months after the trial ends; 12. Patients who have suffered from other malignant tumors within the past 5 years before the first administration (excluding cured carcinoma in situ and basal cell carcinoma of the skin); 13. Patients with combined swallowing difficulties; 14. Patients who participated in clinical trials of other new drugs or medical devices within the first month of randomization and took the study drug or used the study device; 15. Researchers believe that there are other factors that are not suitable for participating in the experiment.