Inclusion Criteria:
1. Healthy male or female participants aged 18 to 45 years, inclusive.
2. Body mass index (BMI) from 19.0 to 26.0 kg/m², inclusive, with a body weight of at least 50 kg for males and at least 45 kg for females.
3. Participants who voluntarily sign the informed consent form before any study-related procedure and fully understand the study content, procedures, and potential adverse reactions.
4. Participants who are able to communicate effectively with the investigator and understand and comply with all study requirements.
5. Participants who are willing to receive an ACYW135 meningococcal vaccine and a pneumococcal vaccine at least 14 days before the first dose. Repeat vaccination is not required if the participant received a pneumococcal vaccine within 5 years before dosing or an ACYW135 meningococcal vaccine within 3 years before dosing.
Exclusion Criteria:
1. Participation in any other drug clinical trial and receipt of an investigational medicinal product within 3 months before admission to the clinical research unit.
2. A history of chronic or active gastrointestinal disease within 3 years before admission, including esophageal disease, gastritis, gastric ulcer, gastroesophageal reflux disease, enteritis, active gastrointestinal bleeding, or gastrointestinal surgery, that is considered clinically significant by the investigator.
3. A confirmed disease of the central nervous, cardiovascular, gastrointestinal, respiratory, endocrine, urinary, hematologic and lymphatic, or metabolic system requiring medical intervention, or any other condition, including a psychiatric history, that may make the participant unsuitable for the study.
4. A known or suspected history of immunodeficiency, such as frequent recurrent infections, or a history of hereditary or acquired complement deficiency.
5. A confirmed history of infection caused by encapsulated microorganisms within 6 months before admission, including but not limited to Streptococcus pneumoniae, Bacillus anthracis, Salmonella species, Salmonella Typhi, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacteroides fragilis, Neisseria meningitidis, Haemophilus influenzae, or Legionella pneumophila.
6. A history of tuberculosis infection or current tuberculosis infection.
7. An active systemic bacterial, viral, or fungal infection within 14 days before the first dose.
8. Symptoms such as dizziness, headache, abdominal pain, diarrhea, or constipation within 14 days before the first dose that, in the investigator's opinion, make the participant unsuitable for the study.
9. Known hypersensitivity to either study intervention, any of their components, or related preparations, or a history of allergy to drugs, food, or other substances.
10. Inability to tolerate venipuncture or a history of fainting in response to blood or needles.
11. Surgery within 6 months before admission that, in the investigator's opinion, may affect drug absorption, distribution, metabolism, or excretion; any surgical procedure within 30 days before admission; or planned surgery during the study.
12. Use of any medication within 28 days before admission, including prescription drugs, nonprescription drugs, traditional Chinese medicines, Chinese patent medicines, or dietary supplements, or use within 5 half-lives of the medication at screening, whichever period is longer.
13. Receipt of any vaccine, including a live attenuated vaccine, within 14 days before the first dose, except for the meningococcal and pneumococcal vaccines required by the protocol, or planned vaccination during the study.
14. Corrected QT interval (QTc) of at least 450 milliseconds for males or at least 460 milliseconds for females at screening.
15. Blood donation or significant blood loss of more than 400 mL, blood transfusion, or receipt of blood products within 3 months before admission, or an intention to donate blood or blood components during the study or within 3 months after study completion.
16. A history of drug abuse or use of soft drugs, such as marijuana, or hard drugs, such as cocaine or phencyclidine, within 1 year before admission.
17. Regular smoking or smoking more than 5 cigarettes per day within 3 months before admission, or inability to discontinue all tobacco products during the study.
18. Alcohol abuse or regular alcohol consumption within 6 months before admission, defined as more than 14 units of alcohol per week, where 1 unit is equivalent to 360 mL of beer, 45 mL of 40% spirits, or 150 mL of wine, or unwillingness to abstain from alcohol and alcohol-containing products during the study.
19. Consumption of excessive amounts of tea, coffee, or other caffeinated beverages, defined as more than 8 cups per day, with 1 cup equal to 250 mL, or unwillingness to discontinue such beverages during the study.
20. Consumption within 7 days before admission of grapefruit, grapefruit-containing products, or other foods that may affect drug absorption, distribution, metabolism, or excretion, or unwillingness to avoid such foods during the study.
21. Special dietary requirements or inability to comply with the standardized diet provided during the study.
22. Female participants who are pregnant or breastfeeding; who have had unprotected sexual intercourse within 14 days before admission; who have used oral contraceptives within 30 days before admission; or who have used long-acting estrogen or progestogen injections or implants within 6 months before admission.
23. Participants, or their partners, who plan pregnancy or sperm or oocyte donation from the time of signing informed consent through 3 months after the last dose, or who are unwilling to use at least one nonpharmacologic contraceptive method, such as complete abstinence, an intrauterine device, or partner sterilization.
24. Clinically significant abnormalities, as determined by the investigator, in physical examination, electrocardiogram, abdominal ultrasound, chest radiograph, vital signs, or laboratory examinations, including hematology, urinalysis, blood chemistry, procalcitonin, coagulation, thyroid function, infectious disease screening, or serum pregnancy testing for females.
25. A positive alcohol breath test or drug abuse screening result.
26. Any other condition that, in the investigator's opinion, may prevent the participant from completing the study or otherwise make the participant unsuitable for participation.
