The nucleobase guanine at the 3’-terminus ofoligonucleotide RGLS4326 drives off-targetAMPAR inhibition and CNS toxicity
Published on 11.28.2025 in Nature Communications
Tania Valencia, Laura Y. Yen, Cindy Berman, Thomas Vincent, Scott Davis, Francesca Varrone, Jianfeng Huang, Jessica Mastroianni, Morgan Carlson, Tate Owen, Amin Kamel, Denis Drygin, Garth A. Kinberger, Shanti Pal Gangwar, Maria V. Yelshanskaya, John Ridley, Robert Kirby, Jesus Alvarez, Ronak Lakhia, Vishal Patel, Alexander I. Sobolevsky & Edmund C. Lee
Designing safe and effective oligonucleotide (ON) therapeutics requires thorough understanding of structural-activity relationship (SAR) with the intended on-target(s) as well as the unintended off-target(s). Despite encouraging pharmacodynamic activity in a Phase 1b study, development of the first-generation anti-miR-17 ON RGLS4326 for the treatment of autosomal dominant polycystic kidney disease was discontinued due to dose-limiting central nervous system (CNS)-related toxicity observed in nonclinical chronic toxicity studies. Here, we provide SAR evidence that the nucleobase guanine at the 3’-terminus of RGLS4326 drives an unexpected off-target aptamer-like direct interaction with α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), thereby causing CNS toxicity. By replacing the 3’-terminal guanine with adenine, we discover the next-generation anti-miR-17 RGLS8429that is devoid of off-target AMPAR interaction and CNS toxicity while preserving the potency against the on-target miR-17. Here, we show a way to avoid off-target CNS effects and, more importantly, data that support the clinical development of RGLS8429
