Phase IIa Study of Flonoltinib Maleate Tablets in the Treatment of Patients With Polycythemia Vera

This trial adopts an open, randomized, parallel controlled, multicenter clinical trial design planning to enroll patients with polycythemia vera who are resistant/intolerant to hydroxyurea or interferon. The study divided into two stages: dose exploration stage: three dose groups are set, with three subjects in each group, totally nine subjects in each group; Dose expansion stage: Based on the safety, efficacy, and pharmacokinetic results of the comprehensive dose exploration stage, 2-3 dose groups are planned to be selected for dose expansion stage.

Inclusion Criteria: 1. Age \>= 18 years old and gender not limited when signing the informed consent form; 2. Diagnosed as PV according to WHO standards (2016 edition), and resistant/intolerant to hydroxyurea or interferon treatment (refer to attachments 1 and 2); 3. When screening, the peripheral blood blasts are 0%; 4. Meet any of the following criteria and achieve HCT\45% at the time of screening; 5.When screening, laboratory test indicators meet the following criteria: neutrophil count \>= 1.0 × 10 \^ 9/L, platelet count \>= 100 × 10 \^ 9/L and \