AAV-based gene therapy with modified HEXB confers lasting therapeutic benefits in GM2 gangliosidosis models.

Kitakaze, Keisuke; Ohnishi, Yukiya; Tsuji, Daisuke; Watanabe, Ryosuke; Kamori, Nijiho; Katakai, Yuko; Shibata, Hiroaki; Yoshizawa, Sota et al. · Cell Rep Med · 2026

basic_science · Level V

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Abstract

GM2 gangliosidoses, including Tay-Sachs (TSD) and Sandhoff (SD) diseases, are lysosomal storage disorders with neurological manifestations caused by the excessive accumulation of GM2 ganglioside due to the deficiency of the β-hexosaminidase A (HexA). Although gene therapy approaches are underway, concerns regarding efficacy and safety remain. Here, we evaluate a tyrosine-mutant adeno-associated virus serotype 9 (AAV9/3) vector encoding modified HEXB (modHEXB) wherein nine amino acid residues are substituted from HEXA. The intracerebroventricular administration of AAV9/3-modHEXB in SD mice results in modHexB expression in the brain, reduces GM2 accumulation, and attenuates neuroinflammation. Furthermore, AAV9/3-modHEXB rescues motor function, and longer lifespan in SD mice. In addition, intrathecal administration in non-human primates and rats demonstrates broad biodistribution and an overall favorable safety profile. These findings support the translational potential of AAV9/3-modHEXB as a gene therapy approach for TSD and SD.