A Study of MY008211A in Adult Patients With Paroxysmal Nocturnal Hemoglobinuria (PNH)

A Multi-center, Randomized, Open-label, Phase 2 Study to Evaluate the Efficacy and Safety of MY008211A Tablets in Adult Patients With Paroxysmal Nocturnal Hemoglobinuria and Active Hemolysis.

The main purpose of this study is to evaluate the efficacy of MY008211A in adult patients with PNH , showing signs of active hemolysis, in China.

The purpose of this study is to determine whether MY008211A is efficacious and safe for the treatment of PNH patients who are naive to complement inhibitor therapy, including anti-C5 antibody.

Inclusion Criteria:

• Male and female participants ≥ 18 years of age, BMI≥18 kg/m2，with a diagnosis of PNH confirmed by laboratory tests, according to the PNH diagnostic criteria in the Chinese Guidelines for the Diagnosis and Treatment of Rare Diseases (2019 edition) , and flow cytometry with clone size ≥ 10%.
• Mean hemoglobin level <100 g/L.
• LDH > 1.5 x Upper Limit of Normal (ULN)
• 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:

• Patients with reticulocytes <100x10^9/L; platelets <30x10^9/L; neutrophils <0.5x10^9/L.
• Were using a complement inhibitor before the first administration of MY008211A tablets or had discontinued a previous complement inhibitor for less than five half-lives or 120 days, whichever was the longest.
• History of recurrent invasive infections caused by encapsulated organisms, e.g. meningococcus or pneumococcus.
• Known or suspected hereditary complement deficiency
• Previous bone marrow or hematopoietic stem cell transplantation.
• Previous splenectomy.
• 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.