Ionis Pharmaceuticals, Inc. and its partner Roche Holding Ltd. announced on September 23, 2026, that the ongoing Phase 3 IMAgINATION study met its primary endpoint. The study evaluated sefaxersen, an investigational antisense inhibitor of complement factor B, in adults with primary IgA nephropathy (IgAN).
The interim analysis, conducted at 37 weeks, demonstrated that sefaxersen achieved statistically significant and clinically meaningful improvements in proteinuria reduction compared to placebo. Proteinuria was measured by the 24-hour urine protein-to-creatinine ratio (UPCR). The filing notes that a reduction in UPCR is strongly associated with the preservation of long-term kidney function.
Sefaxersen is a once-monthly subcutaneous injection designed for self-administration. The safety and tolerability profile of the drug was consistent with previously reported data, with no new safety signals identified.
The IMAgINATION study is a multicenter, randomized, double-blind, placebo-controlled trial. It enrolled 459 patients who were randomized 1:1 to receive sefaxersen or placebo for 105 weeks. The primary endpoint of the study is the change from baseline in the urine protein-to-creatinine ratio at 37 weeks. The study will continue as a blinded study to evaluate the change in kidney function over two years, as measured by estimated glomerular filtration rate (eGFR) at week 105.
Interim analysis data will be presented at an upcoming medical congress and shared with health authorities. The companies stated the goal is to bring the treatment to patients as soon as possible.
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. The company is also eligible to receive regulatory and sales milestone payments as well as tiered royalties on net sales of sefaxersen.
