Lebers Hereditary Optic Neuropathy: Gene Therapy

我们已经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 核遗传密码中复合体I的NADH泛醌氧化还原酶亚单位4(ND4)。这个 通过线粒体靶向序列的代理，蛋白质被输入到线粒体。这个 基因被包装成下一代酪氨酸到苯丙氨酸修饰的自互补 然后将腺相关病毒(AAV)注射到啮齿类动物的眼睛中。旗标野生型人ND4 在注射后1周，90%的视网膜神经节细胞中快速检测到它并整合 此外，在啮齿动物的眼睛中也注射了突变型G11778A ND4同系物 在大多数LHON病例中，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凋亡，防止视神经死亡 视神经中长期存在的轴突。注射自互补野生型ND4 在体外进入人眼的相关滴度在大多数视网膜神经节细胞中表达，提示 它将在我们的LHON患者身上做到这一点。与Leber先天性肥大症(RPE65突变)不同， 目前还没有FDA批准的治疗LHON视力丧失的方法。在过去的4年里，我们有 纳入19例确诊为ND4亚单位G11778A突变的LHON患者 进入I期临床试验，旨在测试我们的基因治疗载体的安全性 (IND#15941)。9例患者玻璃体注射小剂量自互补ScAAV2- P1ND4v2，9只中剂量注射，1只大剂量注射。我们在这方面的目标 竞争性更新应用是测试更高剂量AAV的安全性和耐受性 人ND4基因在我们的突变患者I期临床试验中的介导性传递 G11778A线粒体DNA，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.