Lebers Hereditary Optic Neuropathy: Gene Therapy

我们在确定发病机制和测试治疗方法方面取得了重大进展， Leber遗传性视神经病变（LHON）。我们成功地表达了野生型人类 核遗传密码中复合物I的NADH泛醌氧化还原酶亚基4（ND4）。的 通过线粒体靶向序列的作用将蛋白质导入线粒体。的 基因被包装到下一代酪氨酸到苯丙氨酸修饰的自我互补 腺相关病毒（AAV），然后注射到啮齿动物的眼睛。FLAG标记的野生型人ND4 注射后1周，在90%的视网膜神经节细胞中快速检测到， 进入复合体I此外，在也注射了突变G11778A ND4同源物的啮齿动物眼中， 负责大多数LHON病例，野生型ND4恢复了有缺陷的ATP合成， 抑制视力丧失，减少视网膜神经节细胞的凋亡，防止 视神经中的轴突长期存在。注射的自身互补野生型ND4 在大多数视网膜神经节细胞中表达的离体人眼中的相关滴度，表明 在我们的LHON患者身上也会这样。与Leber先天性黑蒙（RPE 65突变）不同， 对于LHON的视力丧失没有FDA批准的治疗。在过去的四年里， 入组了19名在ND4亚基中具有G11778A突变的基因确认的LHON患者 进入第一阶段临床试验，旨在测试我们的基因治疗载体的安全性， (IND#15941）。9名患者玻璃体注射低剂量自身互补scAAV2， P1ND4v2，9只注射中等剂量，1只注射高剂量。我们的目标是 竞争性更新申请的目的是测试更高剂量的AAV的安全性和耐受性。 在我们的I期临床试验中， G11778A mtDNA，以便在该计划的后期证明疗效。

We have made major strides towards determining the pathogenesis and testing a treatment for Leber Hereditary Optic Neuropathy (LHON). We successfully expressed the wild-type human NADH ubiquinone oxidoreductase subunit 4 (ND4) of complex I in the nuclear genetic code. The protein was imported into the mitochondria by agency of a mitochondrial targeting sequence. The gene was packaged into next generation tyrosine to phenylalanine modified self-complementary adenoassociated virus (AAV) then injected into rodent eyes. FLAG-tagged wild-type human ND4 was detected quickly in 90% of retinal ganglion cells by 1 week post injection and it integrated into Complex I. Furthermore, in rodent eyes also injected with a mutant G11778A ND4 homologue responsible for most cases of LHON, wild-type ND4 restored defective ATP synthesis, suppressed visual loss, reduced apoptosis of retinal ganglion cells and prevented demise of axons in the optic nerve that persisted long-term. The self-complementary wild-type ND4 injected at the relevant titer into the ex vivo human eye expressed in most retinal ganglion cells, suggesting that it will do so in our LHON patients. Unlike Leber Congenital Amaurosis (RPE65 mutation), there is no FDA approved treatment for the visual loss of LHON. Over the past 4 years we have enrolled 19 LHON patients with genetic confirmation of the G11778A mutation in the ND4 subunit of complex I into a phase I clinical trial designed to test the safety of our gene therapy vector (IND# 15941). Nine patients were vitreally injected with low dose self-complementary scAAV2- P1ND4v2, nine injected with medium doses and one injected with high dose. Our goal in this competing renewal application is to test the safety and tolerability of higher doses of AAV mediated delivery of the human ND4 gene in our phase I clinical trial of patients with mutated G11778A mtDNA in order to move to prove efficacy in the later years of this program.