ALT A bar chart from the Original Article "Interim Analysis of a Phase 3 Trial of Povetacicept in IgA Nephropathy.” The trial name, RAINIER AIS-D08, is in parentheses after the title. The chart shows change in 24-hr urinary protein-to-creatinine ratio at week 36. The trial results are being presented at the American Society of Nephrology Kidney Week 2026. The logo of the New England Journal of Medicine is at the bottom.

ALT Four panels showing the mean change in estimated glomerular filtration rate (GFR), annualized estimated GFR slope, and composite kidney-disease progression. Panel A is a graph that shows the mean change in the estimated GFR from baseline through week 104 for atacicept and placebo. Panel B is a bar chart that shows the mean change in the estimated GFR from baseline to week 52 for atacicept and placebo and the between-group difference. Panel C is a bar chart that shows the annualized estimated GFR slope through week 104 for atacicept and placebo and the between-group difference. Panel D is a bar chart that shows the number and percentage of patients who had a reduction from baseline in the estimated GFR of at least 30% that was sustained for at least 30 days and those who had progression to dialysis, kidney transplantation, or death (not including one patient in the placebo group who received transient dialysis for acute kidney injury).

ALT This image shows a forest plot comparing atacicept and placebo. It includes data for subgroups based on age, race, geographic region, urinary protein-to-creatinine ratio, estimated glomerular filtration rate (GFR), and SGLT2 inhibitor use.

ALT Two graphs showing the composite kidney end point (full analysis population). Panel A shows the least-squares mean change in the estimated glomerular filtration rate (eGFR) from baseline to 24 months, analyzed by the repeated-measures model, in the full analysis population, which included all patients who underwent randomization. Panel B shows the progression to a composite of kidney-function decline or kidney failure.

ALT A forest plot displaying the effectiveness of sibprernlimab versus placebo across various subgroups. Subgroups include demographic characteristics like age and race, as well as geographic region and stratification factors. Each subgroup is represented with bars indicating slope differences in ml/min/1.73 m² per year with 95% confidence intervals.

ALT A graph shows the mean change in the estimated glomerular filtration rate (GFR) from baseline through week 104 for atacicept and placebo.