Study of Efficacy and Safety of LNP023 in Primary IgA Nephropathy Patients

Inclusion Criteria: * Male and female patients ≥ 18 years of age with an eGFR level and biopsy-confirmed IgA nephropathy as follows: * For patients eGFR\* ≥ 45ml/min/1.73m2, a qualifying biopsy performed within the last 5 years is required. * For patients with eGFR\* 30 to \<45ml/min/1.73m2, a qualifying biopsy performed within 2 years with \< 50% tubulointerstitial fibrosis is required. * For patients with eGFR\* 20 to \<30ml/min/1.73m2, a qualifying biopsy performed at any time. In all cases, if a historical biopsy is not available, one may be performed during screening. \*eGFR calculated using the CKD-EPI formula (or modified MDRD formula according to specific ethnic groups and local practice guidelines) * Proteinuria due to primary diagnosis of IgA nephropathy as assessed at screening by UPCR ≥1 g/g (113 mg/mmol) sampled from FMV or 24h urine collection, as well as at the completion of the run-in period by UPCR ≥1 g/g (113 mg/mmol) calculated as the (geometric) mean of two 24h urine collections obtained within 14 days of each other at baseline. * Vaccination against Neisseria meningitidis and Streptococcus pneumoniae infection is required prior to the start of study treatment. If the patient has not been previously vaccinated, or if a booster is required, vaccine should be given according to local regulations at least 2 weeks prior to first study drug administration. If study treatment has to start earlier than 2 weeks post vaccination, prophylactic antibiotic treatmen…