Study of Safety and Efficacy of MY008211A in Paroxysmal Nocturnal Hemoglobinuria (PNH) Patients Who Are Naive to Complement Inhibitor Therapy

Inclusion Criteria: 1. Male and female participants ≥ 18 years of age and BMI ≥ 18.0 kg/m2 with a diagnosis of PNH confirmed by high-sensitivity flow cytometry with clone size ≥ 10%. 2. Mean hemoglobin level \<100 g/L at screening. 3. LDH \> 1.5 x Upper Limit of Normal (ULN) at screening. 4. Vaccination against Neisseria meningitidis infection is required prior to the start of study treatment. If not received previously, vaccination against Streptococcus pneumoniae and Haemophilus influenzae infections should be given. Exclusion Criteria: 1. Patients with reticulocytes \<100x10\^9/L; platelets \<30x10\^9/L; neutrophils \<0.5x10\^9/L. 2. History of recurrent invasive infections caused by encapsulated organisms,e.g. meningococcus or pneumococcus. 3. Known or suspected hereditary complement deficiency. 4. Previous bone marrow or hematopoietic stem cell transplantation. 5. Previous splenectomy. 6. A history of malignancy within 5 years before screening, except cured local basal cell carcinoma of the skin and carcinoma in situ of the cervix.