Roche has announced late-breaking oral presentation data from the ongoing phase 3 IMAgINATION study in adults with primary IgA nephropathy (IgAN) receiving optimised Standard of Care (SoC), demonstrating that investigational sefaxersen achieved a statistically significant and clinically meaningful 43.1 percent reduction in proteinuria (95 percent Confidence Interval [CI]: 32.5-52.0, P<0.0001), relative to placebo at 37 weeks, as measured by 24-hour Urine Protein-to-Creatinine Ratio (UPCR).

Proteinuria is a key indicator of kidney damage and a reduction in UPCR is strongly associated with the preservation of long-term kidney function. Results presented at the American Society of Nephrology (ASN) Kidney Week 2026 also showed that, among patients with baseline hematuria (blood in urine), a greater proportion of patients achieved hematuria resolution at week 37 with sefaxersen versus placebo.

Brett P Monia, PhD, Chief Executive Officer, Ionis, said, "These data support our belief that sefaxersen is uniquely positioned to treat IgA nephropathy, demonstrating significant and clinically meaningful reduction in proteinuria and offering the potential to help reduce the need for long-term dialysis or kidney transplantation. Sefaxersen is a powerful example of the broad impact of Ionis' innovative science, and based on these results, we believe it has the potential to be an important new treatment option for people living with IgA nephropathy."

The treatment effect in all prespecified subgroups was consistent with the clinically meaningful reductions in proteinuria shown in the primary endpoint results. Sefaxersen was well tolerated with a safety profile consistent with the previously reported phase 2 study, exhibiting no new safety signals.

Sefaxersen is an investigational once-monthly subcutaneous injection designed to enable self-administration for people with IgAN. The IMAgINATION study will continue as a blinded study to evaluate the change in kidney function over 2 years, as measured by estimated glomerular filtration rate (eGFR) at week 105.

Roche will share data with health authorities, with the goal of bringing this treatment to patients as soon as possible.

Typically diagnosed before the age of 40 years, IgAN affects at least 25 adults per million worldwide each year. IgAN, also known as Berger’s disease, is a chronic and progressive autoimmune disease that leads to end-stage kidney disease in up to 50 percent of patients within 20 years of diagnosis. It is the most common form of primary glomerulonephritis (inflammation of the tiny filters, glomeruli, in the kidneys) and is a major cause of Chronic Kidney Disease (CKD) as well as kidney failure.

Roche licensed sefaxersen from Ionis for the treatment of complement-mediated diseases. Under the terms of the agreement, Ionis received an upfront payment, license fee and development milestone payments and is eligible to receive regulatory and sales milestone payments as well as tiered royalties on net sales of sefaxersen.