Jaktinib Hydrochloride Tablets in Intermediate-risk and High-risk Myelofibrosis.

Inclusion criteria: 1、18 years age or older ,male or female; 2、Patients diagnosed with Primary Myelofibrosis according to WHO standard (2016 version), or patients diagnosed with Post-Polycythemia Vera Myelofibrosis or Post-Essential Thrombocythemia Myelofibrosis according to International Working Group Myeloproliferative Neoplasms Research and Treatment(IWG-MRT) standard. Both Janus Kinase 2(JAK2)mutation and JAK2 wild can be enrolled； 3、According to Dynamic International Prognostic Scoring System plus(DIPSS-plus) risk grouping criteria, patients with medium-risk-2 or high-risk myelofibrosis were assessed,Patients with grade 1 medium-risk myelofibrosis with hepatosplenomegaly and no response to existing treatment and requiring treatment can also be enrolled; 4、Subjects did not have a recent stem cell transplant program; 5、a life expectancy \> 24 weeks; 6、Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2； 7、Splenomegaly: palpation of the splenic margin to or above the subcostal at least 5 cm； 8、Peripheral blood protocells ≤10%； 9、Patients who have not previously been treated with JAK inhibitors； 10、Absolute neutrophil count（ANC） ≥1000/uL, platelet count ≥75 × 109/L without growth factor, platelet production factor or platelet infusion.Subjects did not receive growth factor infusion within 2 weeks before randomization; 11、Seven days before randomization, the main organs were functioning normally, which met the following criteria： alanine transaminase（ALT）and aspartate aminotransferase（AST）≤2.5×upper limit of normal (ULN)； direct bilirubin（DBIL）and total bilirubin (TBIL)≤1.5×upper limit of normal (ULN）；serum creatinine ≤2.5×upper limit of normal (ULN)，calculated creatinine clearance（CrCl）≥50mL/min； 12、 Voluntarily sign informed consent in accordance with the requirements of the ethics committee; 13、Ability to follow study and follow-up procedures； Exclusion Criteria: 1. Any significant clinical or laboratory abnormalities that the investigator considers to affect safety assessment, such as: a. uncontrolled diabetes (\> 250 mg/dL, or 13.9 mmol \> / L), b. had high blood pressure and antihypertensive drug treatment under two or unable to descend to the ranges (systolic blood pressure \< 160 mmHg, diastolic pressure \< 100 mmHg), c. peripheral neuropathy (NCI - CTC AE v4.03 standard grade 2 or above), d. thyroid dysfunction (\> NCI - CTC AE v4.03 standard grade 2 or above); 2. The patients had a history of congestive heart failure, uncontrollable or unstable angina or myocardial infarction, cerebrovascular accident or pulmonary embolism in the first 6 months; 3. Screening of patients who have not fully recovered from surgery within the first 4 weeks; 4. Screening for patients with arrhythmia requiring treatment or QTc interval (QTcB) \>480ms; 5. Screening for bacterial, viral, parasitic or fungal infections with any clinical symptoms that require treatment; 6. Patients with a history of congenital or acquired hemorrhagic diseases; 7. Patients who had previously undergone splenectomy or who had received radiotherapy of the splenic region within the first 12 months of screening; 8. Screening for HIV positive, active hepatitis b virus positive (HBsAg positive, hbv- dna positive or greater than 1000 copies /ml), anti-hcv antibody or hcv-rna positive; 9. Patients suffering from epilepsy or using psychotropic or sedative drugs at the time of screening; 10. Women who are planning to become pregnant or who are pregnant or breast- feeding, as well as those who were unable to use effective contraceptives throughout the trial;Male patients who do not use condoms during the administration and within 2 days (approximately 5 half-lives) after the last administration; 11. Patients who have suffered from malignant tumors (except cured basal cell carcinoma of the skin and carcinoma in situ of the cervix) in the past 5 years; 12. Combined with other serious diseases, the researchers believe that patients' safety or compliance may be affected; 13. Suspected allergic to Jakatinib hydrochloride or similar drugs; 14. Patients who have participated in the clinical trials of other new drugs or medical devices within the first 3 months; 15. Patients who were treated with any MF drug (e.g., hydroxyl urea), any immunomulator (e.g., thalidomide), any immunosuppressant, prednisone at or above 10mg/ day or equivalent bioactive level of glucocorticoid, growth factor (e.g.,erythropoietin ), or who were within 6 half-lives of the drug within 2 weeks prior to randomization;