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# Roche's Sefaxersen Cuts Protein Loss 43.1% In Late-Stage Kidney Trial Of Ionis-Discovered Drug
- URL: https://www.bullished.co/roches-sefaxersen-cuts-protein-loss-43-1-in-late-stage-kidney-trial-of-ionis-discovered-0b4dc20e/
- Published: 2026-10-23T17:51:33.000Z
- Updated: 2026-10-23T17:51:33.000Z
- Description: Ionis said the once-monthly shot beat placebo on its main goal in IgA nephropathy, with no new safety signals.
- Author: Matteo Parrino
- Tags: SEC Filings, IONS, Industry: Healthcare

[Ionis Pharmaceuticals](https://www.bullished.co/tag/ions/), which develops RNA-targeted medicines, said Friday that partner Roche's late-stage trial of sefaxersen in IgA nephropathy met its main goal, cutting proteinuria [43.1% versus placebo](https://www.sec.gov/Archives/edgar/data/0000874015/000114036126040631/ef20084325%5F8k.htm?ref=bullished.co) at 37 weeks. Roche plans to take the data to health authorities.

## A 43.1% drop in proteinuria

The result came from the Phase 3 IMAgINATION study, presented as a late-breaking oral talk at the American Society of Nephrology Kidney Week 2026\. Proteinuria, protein leaking into urine, is a key marker of kidney damage. The 95% confidence interval ran from 32.5 to 52.0, with P<0.0001, measured by 24-hour urine protein-to-creatinine ratio.

The [press release](https://www.sec.gov/Archives/edgar/data/0000874015/000114036126040631/ef20084325%5Fex99-1.htm?ref=bullished.co) said the effect was consistent across all prespecified subgroups. Among patients with blood in the urine at the start, more reached resolution at Week 37 on sefaxersen than on placebo. Safety matched the earlier Phase 2 study, with no new signals.

The trial enrolled 459 people, randomized 1:1 to sefaxersen or placebo for 105 weeks. Ionis CEO Brett P. Monia said the data support the belief that sefaxersen is "uniquely positioned to treat IgA nephropathy."

## A monthly shot for a progressive disease

Sefaxersen is an investigational once-monthly injection under the skin, designed for self-administration at home. It is a liver-directed antisense drug that blocks production of complement factor B, and the release calls it the first RNA-targeted therapy for the disease.

IgA nephropathy is a chronic autoimmune kidney disease, typically diagnosed before age 40, that leads to end-stage kidney disease in up to 50% of patients within 20 years of diagnosis, according to the company.

Ionis has seven marketed medicines and reported $944 million of revenue for 2025\. Roche licensed sefaxersen from Ionis for complement-mediated diseases. Ionis received an upfront payment, a license fee and development milestone payments, and can earn regulatory and sales milestones plus tiered royalties on net sales.

## Shares slip as the study runs on

IONS shares traded at $42.79 in Friday trading, down 2.55% from Thursday's close of $43.91.

IMAgINATION continues as a blinded study to track kidney function by estimated glomerular filtration rate at week 105\. Separately, Ionis partner GSK [announced FDA approval](https://markets.ft.com/data/announce/detail?dockey=600-202610202120BIZWIRE%5FUSPRX%5F%5F%5F%5F20261020%5FBW102530-1&ref=bullished.co) of bepirovirsen as Hibsago for chronic hepatitis B on October 20.

Roche says it will share the data with health authorities, aiming to bring the treatment to patients as soon as possible.

### Sources

- [8-K Filing — IONIS PHARMACEUTICALS INC (IONS)](https://www.sec.gov/Archives/edgar/data/0000874015/000114036126040631/ef20084325%5F8k.htm?ref=bullished.co) — SEC EDGAR
- [Exhibit ef20084325\_ex99-1.htm — IONIS PHARMACEUTICALS INC 8-K exhibit](https://www.sec.gov/Archives/edgar/data/0000874015/000114036126040631/ef20084325%5Fex99-1.htm?ref=bullished.co) — SEC EDGAR
- [Ionis partner GSK announces Hibsago (bepirovirsen) approved in the U.S. for the treatment of chronic hepatitis B (CHB) – Company Announcement - FT.com](https://markets.ft.com/data/announce/detail?dockey=600-202610202120BIZWIRE%5FUSPRX%5F%5F%5F%5F20261020%5FBW102530-1&ref=bullished.co) — Financial Times

### More on Ionis Pharmaceuticals

- [FDA Approves Hibsago, GSK's Hepatitis B Drug From Ionis, With 10-12% Royalties And A Boxed Warning](https://www.bullished.co/fda-approves-hibsago-gsks-hepatitis-b-drug-from-ionis-with-10-12-royalties-and-a-boxed-5562e0e0/)

[All Ionis Pharmaceuticals (IONS) coverage →](https://www.bullished.co/tag/ions/)