Decision that continuing with the study would not generate useful data

This is a Phase 2, multi-center, randomized, double-blind, placebo-controlled clinical study with an optional open label extension to evaluate the safety and efficacy of Telitacicept for Injection (RC18) in the treatment of IgA nephropathy.

IgA nephropathy is a kidney disease in which IgA, a protein meant to defend the body against foreign invaders, accumulates in the kidneys and damages them. This study will seek to determine the safety and efficacy of Telitacicept for Injection (RC18) in the treatment of IgA nephropathy.

The study is composed of 4 parts: a screening period, a double-blind treatment period, an optional open label extension, and a follow-up period. Subjects with confirmed IgA nephropathy will be enrolled and randomized 1:1:1 to Telitacicept 160 mg, Telitacicept 240 mg, or placebo (10 per arm).

Inclusion Criteria:

1. IgA nephropathy confirmed by pathological biopsy;
2. Male or female aged ≥ 18 years old;
3. Average 24-hour urine total protein ≥ 0.75 g/24 h
4. Estimated GFR (using the CKD-EPI formula) > 30 mL/min per 1.73 m^2;
5. Stabilized AEI/ARB medications, diuretics, or other antihypertensive therapy.

Exclusion Criteria:

1. Patients with clinically significant abnormal laboratory tests at screening;
2. Evidence of rapid eGFR decrease > 15 ml/min during screening;
3. Renal or other organ transplantation prior to, or expected during, the study;
4. Patients with secondary IgA nephropathy;
5. Patients with nephrotic syndrome, crescentic nephritis minimal change nephropathy with IgA deposition, or other pathological or clinical types of renal diseases that may confound the study data interpretation;
6. Patients with history of any severe unstable cardiovascular and cerebrovascular events within 12 weeks prior to screening;
7. Immunocompromised individuals.