New drug YKST02 aims to tame kidney disease in early trial

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Diagnosis of primary IgA nephropathy (IgAN) * Proteinuria above a protocol-defined threshold at screening * Receiving stable standard-of-care therapy for IgAN for an adequate duration prior to enrollment, unless contraindicated or not tolerated * Women of childbearing potential must have a negative pregnancy test prior to study drug administration and agree to use effective contraception; male participants must agree to use effective contraception * Able to understand the study procedures and provide written informed consent Exclusion Criteria: * Secondary IgA nephropathy (e.g., associated with liver disease, autoimmune disorders, infections, or other systemic conditions) * Other clinically significant renal diseases unrelated to IgAN (e.g., diabetic nephropathy, lupus nephritis, vasculitis) * Nephrotic syndrome considered unsuitable for study participation * Rapidly progressive glomerulonephritis or rapidly declining renal function * Estimated glomerular filtration rate (eGFR) \<45 mL/min/1.73 m² * Immunodeficiency or low immunoglobulin G (IgG) levels below normal * Clinically significant abnormal laboratory findings (e.g., hematologic, hepatic, or coagulation abnormalities) * Requirement for systemic corticosteroids for concomitant conditions * Use of immunosuppressive, targeted, or biologic therapies within a defined period prior to screening or anticipated use during the study * Prior treatment with B-cell-depleting or other targeted biologic therapies within a defined period * History of demyelinating disorders (e.g., multiple sclerosis) * Clinically significant cardiovascular or cerebrovascular disease within 6 months prior to screening * History of organ transplantation or planned transplantation during the study * Current dialysis or anticipated need for dialysis during the study * Major surgery within 4 weeks prior to screening or planned during the study * Active infection requiring systemic therapy, recent serious infection, or chronic/recurrent infections * Known active hepatitis B, hepatitis C, or human immunodeficiency virus (HIV) infection * Active or untreated latent tuberculosis * History of splenectomy * Uncontrolled comorbidities (e.g., poorly controlled hypertension or diabetes) * Malignancy within the past 5 years, except adequately treated non-invasive cancers * Known hypersensitivity to YKST02 or its components * Receipt of another investigational product within 4 weeks or 5 half-lives (whichever is longer) prior to screening * Receipt of live or attenuated vaccines within 4 weeks prior to screening or planned during the study * Any condition that, in the investigator's judgment, would make the participant unsuitable for the study