Abstract：
Fabry disease (FD) is a multisystemic lysosomal storage disorder caused by the loss of α-galactosidase A (α-Gal) function. The current standard of care, enzyme replacement therapies, while effective in reducing kidney pathology when treated early, do not fully ameliorate cardiac issues, neuropathic manifestations, and risk of cerebrovascular events. Adeno-associated virus (AAV)-based gene therapies (AAV-GT) can provide superior efficacy across multiple tissues owing to continuous, endogenous production of the therapeutic enzyme and lower treatment burden. We set out to develop a robust AAV-GT to achieve optimal efficacy with the lowest feasible dose to minimize any safety risks that are associated with high-dose AAV-GTs. In this proof-of-concept study, we evaluated the effectiveness of an rAAV9 vector expressing human GLA transgene under a strong ubiquitous promoter, combined with woodchuck hepatitis virus posttranscriptional regulatory element (rAAV9-hGLA). We tested our GT at three different doses, 5e10 vg/kg, 2.5e11 vg/kg, and 6.25e12 vg/kg in the G3Stg/GLAko Fabry mouse model that has tissue Gb3 substrate levels comparable with patients with FD and develops several early FD pathologies. After intravenous injections of rAAV9-hGLA at 11 weeks of age, we observed dose-dependent increases in α-Gal activity in the key target tissues, reaching as high as 393-fold of WT in the kidneys and 6156-fold in the heart at the highest dose. Complete or near-complete substrate clearance was observed in animals treated with the two higher dose levels tested in all tissues except for the brain. We also found dose-dependent improvements in several pathological biomarkers, as well as prevention of structural and functional organ pathology. Taken together, these results indicate that an AAV-GT under a strong ubiquitous promoter has the potential to address the unmet therapeutic needs in patients with FD at relatively low doses.
摘要：
法布里病(FD)是由α-半乳糖苷酶A(α-Gal)功能丧失引起的多系统溶酶体贮积症。目前的护理标准，酶替代疗法（ERT），虽然早期治疗可有效减少肾脏病理，不能完全改善心脏问题，神经病表现，和脑血管事件的风险。基于AAV的基因治疗（AAV-GT）可以在多个组织中提供优异的疗效，内源性产生治疗性酶，降低治疗负担。我们着手开发一种强大的AAV-GT，以最低的可行剂量达到最佳疗效，以最大程度地减少与高剂量AAV-GT相关的任何安全风险。在这项概念验证研究中，我们评估了在强普遍存在的启动子下表达人GLA转基因的rAAV9载体的有效性。结合土拨鼠肝炎病毒转录后调控元件（WPRE）（rAAV9-hGLA）。我们测试了三种不同剂量的GT，5e10vg/kg，2.5e11vg/kg,和6.25e12vg/kg在G3Stg/GLAKOFabry小鼠模型中，其组织Gb3底物水平与FD患者相当，并发展出几种早期FD病理。在11周龄静脉注射rAAV9-hGLA后，我们观察到关键靶组织中α-Gal活性的剂量依赖性增加，在最高剂量下，肾脏中的WT高达393倍，心脏中的WT高达6156倍。在用两种较高剂量水平处理的动物中观察到完全或接近完全的底物清除,在除了脑以外的所有组织中进行测试。我们还发现了几种病理生物标志物的剂量依赖性改善，以及结构和功能器官病理学的预防。一起来看,这些结果表明,在强普遍存在启动子下的AAV-GT具有在相对低剂量下解决FD患者未满足的治疗需求的潜力.
