On October 23, 2026, Ionis Pharmaceuticals, Inc. reported that its partner, Roche, announced late-breaking oral presentation data from the ongoing Phase 3 IMAgINATION study. The study evaluated sefaxersen, an investigational antisense inhibitor of complement factor B, in adults with primary IgA nephropathy (IgAN) receiving optimized standard of care.
The data demonstrated that sefaxersen achieved a statistically significant and clinically meaningful 43.1% reduction in proteinuria, relative to placebo at 37 weeks. The reduction was measured by the 24-hour urine protein-to-creatinine ratio (UPCR), with a 95% confidence interval of 32.5 to 52.0 and a P-value of less than 0.0001.
Results presented at the American Society of Nephrology Kidney Week 2026 also indicated that among patients with baseline hematuria, a greater proportion achieved hematuria resolution at Week 37 with sefaxersen compared to placebo. The treatment effect was consistent across all prespecified subgroups.
Sefaxersen was well tolerated, with a safety profile consistent with the previously reported Phase 2 study and exhibiting no new safety signals. The treatment is designed as a once-monthly subcutaneous injection intended for self-administration.
The IMAgINATION study will continue as a blinded study to evaluate the change in kidney function over two years, measured by estimated glomerular filtration rate (eGFR) at week 105. Roche plans to share the data with health authorities with the goal of bringing the treatment to patients as soon as possible.
The IMAgINATION study (NCT05797610) enrolled 459 people randomized 1:1 to receive sefaxersen or placebo for 105 weeks. The primary endpoint of the study was the change from baseline in the urine protein-to-creatinine ratio at 37 weeks.
