A Study of SC0062 Capsule for the Treatment of IgA Nephropathy with Proteinuria

Inclusion Criteria:

• Voluntarily sign informed consent and fully understand and comply with trialprocedures;

• Age ≥18 years old, gender unlimited;

• IgA nephropathy patients with proteinuria must meet all of the following conditions:

1. According to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI,

2009. creatinine equation, after 12 weeks of the stable use of the backgroundtherapy, the mean of two estimated glomerular filtration rates (eGFR)calculated from central laboratory results was ≥ 30 and < 90 mL/min/1.73m2.

2. Received the maximum labeled or tolerated dose of RAASi (ACEI or ARB) for atleast 12 weeks before randomization; If subjects were treated with SGLT2i, MRA,or GLP-1RA prior to randomization, the stable use was also required for atleast 12 weeks (maximum tolerated and optimal dose determined by theinvestigator; Subjects who are intolerant to RAASi may also be enrolled).

3. The pathological examination confirmed IgA nephropathy. Two 24-hour urinesamples were collected during the screening period, after 12 weeks of thestable use of the background treatment. Both of the results conducted by thecentral laboratory were met: 24-hour urine protein to creatinine ratio (UPCR) ≥ 0.75 g/g or 24-hour urinary protein excretion rate (UPER) ≥ 1.0 g.

• Laboratory tests shall meet the following criteria:

1. Serum albumin ≥ 30 g/L;

2. Hemoglobin ≥ 90 g/L ; Platelet count ≥80×109/L;

3. Brain natriuretic peptide (BNP) ≤ 200 pg/mL or N-terminal pro B-typenatriuretic peptide (NT-proBNP) ≤ 600 pg/mL;

4. Blood potassium ≤ 5.5 mmol/L;

5. Systolic blood pressure (SBP) ≤ 160 mmHg;

6. Hemoglobin A1c ≤ 8%;

7. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2×ULN;Total bilirubin ≤ 1.5×ULN;

• During the entire study period from the signing of the informed consent to 3 monthsafter the final administration, fertile females and males who have not receivedvasectomy should take effective contraceptive measures [Effective contraceptivemeasures include: Vasectomy, intrauterine device (IUD), hormones (oral, patch, ring,injection, implant) and barrier methods (diaphragm, cervical cap, sponge, condom).

Exclusion Criteria:

• Pregnant or lactating females; Women of childbearing potential (WOCBP) who have apositive blood pregnancy test before randomization;

• A history of hypersensitivity or allergic to any component of the study drug (SC0062capsule);

• Systemic use of corticosteroids or immunosuppressants for more than 2 weeks within 3months prior to randomization; The following are excluded: local topical orintraarticular, intranasal and inhaled glucocorticoids; Use of biological agents (such as rituximab, Telitacicept, etc.), Iptacopan capsules, budesonideenteric-coated capsules within 6 months prior to randomization;

• Concurrent diagnosis of chronic kidney disease caused by other etiologies (includingpolycystic kidney disease, diabetic kidney disease, or other primary glomerulardisease) as determined by the investigator;

• Secondary IgA nephropathy, including but not limited to: Henoch-Schönlein purpura,ankylosing spondylitis, systemic lupus erythematosus, amyloidosis, etc.

• Renal biopsy results showed that > 25% of glomeruli with crescents, or interstitialfibrosis/tubular atrophy > 50%;

• Based on KDIGO guidelines, rapidly progressive glomerulonephritis was clinicallysuspected (judged by the investigator);

• Nephrotic syndrome (UPER > 3.5g/d and serum albumin < 30g/L, with or without edemaand hyperlipidemia) at screening;

• A history of any lung disease requiring oxygen therapy (e.g., chronic obstructivepulmonary disease, emphysema, pulmonary edema, etc.);

• Use of the same class drug (endothelin receptor antagonist, ERA) beforerandomization;

• A history of moderate or severe edema, non-traumatic facial edema, or myxedemawithin the 6 months prior to randomization;

• A history of orthostatic hypotension within 6 months before randomization;

• A history of clinically significant cirrhosis assessed by the investigator;

• A history of worsening heart failure, acute coronary syndrome, transient ischemicattack, stroke and other serious cardiovascular and cerebrovascular diseases within 6 months prior to randomization, or NYHA Grade III to IV at screening;

• A history of kidney or other organ transplantation (except corneal transplantation);

• A condition which had the potential to interfere with oral drug absorption, such assubtotal gastrectomy, clinically severe gastrointestinal disorders, or certain typesof bariatric surgery;

• Use of potent CYP3A4 inducers and potent CYP3A4 inhibitors within 2 weeks (14 days)before randomization;

• Received other treatment for IgA nephropathy within 28 days prior to randomizationexcept as permitted by the protocol;

• Active Hepatitis B, active Hepatitis C, active syphilis and Hiv-positive ;

• A history of malignant tumors within 5 years, except for skin squamous cellcarcinoma, colon polyp or in situ cervical cancer, thyroid papillary carcinoma;

• A history of alcohol or drug abuse or dependence, or a history of mental illness;

• Participated in clinical trials of other investigational drugs or medical deviceswithin 3 months prior to randomization;

• Any other clinically significant disease, condition, or medical history that mayinterfere with subjects' safety, study evaluation, and/or study procedures at thediscretion of the investigator;

• Any other reasons for not being suitable for participating in this clinical study atthe discretion of the investigator.