This is a multicenter, open-label study to evaluate the long-term safety and efficacy of XH-S003 capsules in PNH patients. About 26 PNH patients who had received and completed XH-S003 study treatment will be enrolled to take XH-S003 capsules orally according to protocol. Eligible subjects can maintain XH-S003 treatment until the end of the study.

Inclusion Criteria:

1. PNH patients who have previously received and completed the XH-S003 study treatment, and according to the investigator's evaluation, the benefits of treatment outweigh risks and may benefit from continued treatment with XH-S003;
2. Subjects who have been vaccinated against Neisseria meningitidis and Streptococcus pneumoniae as required by previous studies (if the vaccine protection period does not cover the duration of this study, timely booster vaccinations should be administered according to vaccination guidelines and local vaccination requirements);

Exclusion Criteria:

1. . History of malignancy in any organ or system within the past 5 years prior to screening (excluding localized basal cell carcinoma of the skin or in situ cervical cancer);
2. History of bone marrow/hematopoietic stem cell or solid organ transplantation;
3. History of splenectomy;
4. History of serious comorbidities , including but not limited to: advanced stage heart disease (e.g., New York Heart Association [NYHA] Class IV), severe lung disease (e.g., severe pulmonary hypertension [WHO Class IV]), severe liver function injury, severe renal disease (estimated glomerular filtration rate [eGFR] < 30 mL/min/1.73 m2 or chronic kidney disease [CKD] Stage 4 or dialysis patients), unstable thrombus, other hematologic system diseases (e.g., chronic anemia unrelated to PNH), and deemed unsuitable for study participation by the investigator;
5. Pregnant or lactating women, or those with a positive pregnancy test;
6. Known or suspected immunodeficiency diseases or hereditary complement deficiency at screening;
7. A history of Neisseria meningitidis infection