This is a Phase I trial designed to evaluate the impact of renal impairment on the efficacy and safety of the drug by comparing pharmacokinetic (PK) parameters and pharmacodynamic (PD) markers after a single subcutaneous injection of RG002C0106 between trial participants with normal renal function and those with mild to moderate renal impairment.

Inclusion Criteria:

1. Have been fully informed about the study, volunteered to participate, and provided written informed consent.

2. Male or female participants aged 18-60 years (inclusive) at screening.

3. Body mass index (BMI) of 19.0-32.0 kg/m² (inclusive) at screening; body weight ≥ 50 kg for male participants and ≥ 45 kg for female participants.

4. Absolute estimated glomerular filtration rate (eGFR), calculated using the CKD-EPI 2021 equation during the screening period, falls into the corresponding group as follows:

   Normal renal function: absolute eGFR ≥ 90 mL/min; Mild renal impairment: 60 mL/min ≤ absolute eGFR < 90 mL/min; Moderate renal impairment: 30 mL/min ≤ absolute eGFR < 60 mL/min.

5. Female participants of childbearing potential must have a negative serum pregnancy test during the screening period. Highly effective contraception must be used from signing the informed consent form until 6 months after the last dose of the study drug, by the participant and their partner of childbearing potential.

Exclusion Criteria:

1. At screening, chest radiography demonstrates clinically significant abnormalities.

2. Any of the following abnormal laboratory test results at screening:

   Total bilirubin > 1.5 × upper limit of normal (ULN); ALT or AST > 2 × ULN; International normalized ratio (INR) > 2 or any clinically significant abnormality; QTcF ≥ 450 ms in males or QTcF ≥ 470 ms in females (QTc interval must be heart rate-corrected using the Fridericia formula); Other abnormal laboratory test results deemed clinically significant by the investigator.

3. Positive test results for hepatitis B surface antigen, hepatitis C virus antibody, human immunodeficiency virus antibody, or Treponema pallidum antibody at screening.

4. Participants with primary or secondary IgA nephropathy (patients with IgA nephropathy are advised to be screened for the Phase IIa study of the investigational product).

5. Current diagnosis of tuberculosis (TB); history of active TB with cure < 5 years prior to screening; or high likelihood of TB infection as judged by the investigator based on comprehensive TB screening during the screening period.

6. Presence or suspected presence of other active viral, bacterial, fungal, or parasitic infections within 4 weeks before screening.

7. History of epidemic meningococcal infection, or other recurrent or chronic infections.

8. History of splenectomy or asplenia.

9. History of complement abnormalities or hereditary complement deficiency.

10. Development of acute kidney injury within 2 weeks before screening.

11. History of renal transplantation, or requirement for renal dialysis during the study.