HSK-39297

Primary objective: To evaluate the effectiveness of HSK39297 tablets in patients with paroxysmal nocturnal hemoglobinuria (PNH) who are still anemic after C5 monoclonal antibody treatment. Secondary objectives: To evaluate the effect of HSK39297 tablets on the need for blood transfusion in PNH patients who are still anemic after C5 monoclonal antibody treatment; To evaluate the effect of HSK39297 tablets on anemia correction and hemolysis control in PNH patients who are still anemic after C5 monoclonal antibody treatment; To evaluate the improvement of fatigue symptoms in PNH patients who are still anemic after C5 monoclonal antibody treatment with HSK39297 tablets; To evaluate the occurrence of breakthrough hemolysis (BTH) and major adverse vascular events (MAVE) in PNH patients who are still anemic after C5 monoclonal antibody treatment with HSK39297 tablets; To evaluate the safety of HSK39297 tablets in PNH patients who are still anemic after C5 monoclonal antibody treatment; To evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of HSK39297 tablets in PNH patients