与Tay-Sachs病(TSD)和Sandhoff病(SD)相关的GM2神经节苷脂的病理积累发生在由于HEXA和HEKB基因突变而具有异二聚体β-己糖胺酶A(HexA)突变形式的个体中,分别。由于缺乏认可的疗法,患者经历迅速的神经衰退导致早期死亡。携带HEXA和HEXB的新型双顺反子载体先前在新生儿静脉给药后的SD小鼠模型中显示出有希望的结果,包括GM2积累的显著减少,增加十六进制A的水平,生存期延长2倍.本研究的目的是通过鞘内给药途径以及瞬时免疫抑制来确定6周龄SD小鼠中双顺反子载体的最佳剂量,告知可能的临床翻译。测试了三种剂量的双顺反子载体:每只小鼠2.5e11、1.25e11和0.625e11载体基因组。最高剂量提供最大的生化和行为参数的增加,这样治疗小鼠的中位年龄为56周(>SD对照寿命的3倍)。这些结果在决定TSD/SD的人等效剂量方面具有直接意义,并且已经通知临床试验应用的批准(NCT04798235)。
The pathological accumulation of GM2 ganglioside associated with Tay-Sachs disease (TSD) and Sandhoff disease (SD) occurs in individuals who possess mutant forms of the heterodimer β-hexosaminidase A (Hex A) because of mutation of the HEXA and HEXB genes, respectively. With a lack of approved therapies, patients experience rapid neurological decline resulting in early death. A novel bicistronic vector carrying both HEXA and HEXB previously demonstrated promising results in mouse models of SD following neonatal intravenous administration, including significant reduction in GM2 accumulation, increased levels of Hex A, and a 2-fold extension of survival. The aim of the present
study was to identify an optimal dose of the bicistronic vector in 6-week-old SD mice by an intrathecal route of administration along with transient immunosuppression, to inform possible clinical translation. Three doses of the bicistronic vector were tested: 2.5e11, 1.25e11, and 0.625e11 vector genomes per mouse. The highest dose provided the greatest increase in biochemical and behavioral parameters, such that treated mice lived to a median age of 56 weeks (>3 times the lifespan of the SD controls). These results have direct implications in deciding a human equivalent dose for TSD/SD and have informed the approval of a clinical
trial application (NCT04798235).