a study of rc18 administered subcutaneously to subjects with primary iga(immunoglobulin a) nephropathy

Conditions: Primary IgA Nephropathy

Summary: to evaluate the safety and efficacy of tai ai(recombinant human b lymphocyte stimulator receptor-antibody fusion protein for injection) in the treatment of iga nephropathy.

both rc18 and recombinant human b lymphocyte stimulator receptor-antibody fusion protein for injection are other names of tai ai. after a 35-day screen period, subjects are randomly allocated into 3 groups receiving subcutaneous injection of tai ai 160mg, tai ai 240mg, and placebo once a week individually. the treatment lasts 24 weeks. subjects, the sponsor, investigators are blinded in the whole process of the trial.

Eligibility criteria:
inclusion criteria: 1. signing the informed consent; 2. biopsy confirmed diagnosis of iga nephropathy; 3. male or female, between 18 and 70 years age; 4. during screening, 24-hour urine protein excretion ≥0.75 g/24h at visit 1 and/or visit 2 and at visit 3; 5. estimated glomerular filtration rate (egfr) (ckd-epi ) \>35 ml/min per 1.73m\^2; 6. have received the angiotension converting enzyme inhibitors(acei)/angiotensin receptor blocker(arb) standard treatment for 12 weeks prior to randomization, and have stabled the dosage (within the maximum tolerated dosage) for 4 weeks prior to randomization. exclusion criteria: 1. abnormal laboratory tests; 2. any secondary iga nephropathy caused by henoch-schönlein purpura, ankylosing spondylitis, systemic lupus erythematosus, sjogren syndrome, viral hepatitis, liver cirrhosis, rheumatoid arthritis, mixed connective tissue disease, polyarteritis nodosa, erythema nodosum, psoriasis, ulcerative colitis, crohn\&#39;s disease, tumor, aids ,etc.; 3. any nephropathy with special pathologic or clinical types, such as nephrotic syndrome, crescentic glomerulonephritis(with \>50% of biopsied glomeruli), minimal change disease with iga deposition; and iga nephropathy requiring corticosteroids treatment. 4. suffering from cardiovascular and cerebrovascular events (myocardial infarction, unstable angina, ventricular arrhythmia, new york heart association grade iii-iv heart failure, stroke, etc.) within the last 12 weeks; 5. treating with systemic corticosteroids drug(excluding topical or nasal steroids) within 3 months prior to randomizing; 6. treating with systemic immunosuppressor within 3 months prior to randomizing: cyclophosphamide, azathioprine, mycophenolate mofetil, leflunomide, tacrolimus, cyclosporine, rituximab, tripterygium wilfordii, etc.; 7. requiring hospitalization or intravenous antibiotics treatment due to active infection within 3 months prior to randomizing; 8. active tuberculosis or latent carrier without treatment; 9. herpes zoster infected patients or patients with positive hiv antibody or positive hcv antibody; 10. active hepatitis or severe liver disease, and hbv infection (according to the hbv screening test, ① the hbsag-positive; ②hbsag-negative and hbcab-positive, the hbv-dna should be tested to determine the situation: the hbv-dna positive subjects should be excluded, while the hbv-dna negative subjects can participated in.) 11. with malignant tumors; 12. pregnancy ，lactation, or patients with childbearing plans during the trial; 13. nephrotoxic drugs is unavoidable during the study period; 14. allergy to human-derived biologics; 15. receiving any other investigating drug 4 weeks or 5 times half-life of the experimental drug (whichever is longer) prior to randomization; 16. not suitable for the study judged by investigator.