CNS Gene Therapy for CLN2 Disease Using Parallel Multiple Routes of Administration

抽象的。与威尔·康奈尔的水晶实验室合作，LexEO正在开发一种腺相关- 重组病毒(AAV)基因治疗慢性淋巴细胞性脑炎的中枢神经系统表现 (巴顿)病，一种致命的儿童常染色体隐性遗传性神经退行性溶酶体储存障碍 由CLN2基因突变引起，该基因编码一种溶酶体酶--三肽基肽酶1(TPP-I)。 TPP-I活性的丧失导致溶酶体中储存物质的积累和由此产生的神经元 伴有进行性神经变性的细胞死亡。基因型/表型比较表明，严重的 随着中枢神经系统TPP-I水平升高到正常水平的5~10%，表型应得到改善。这可能是 可以使用AAV载体高效地将基因转移到中枢神经系统，介导持久的前 抑制TPP-I，一种分泌的蛋白质，能够通过被人摄取而交叉校正相邻细胞- 鼻型6-磷酸受体。然而，由于CLN2病的中枢神经系统表现贯穿于 对于大脑来说，该疗法调节中枢神经系统的广泛分布是至关重要的。基于对中国的药效研究 CLN2-/-小鼠和中枢神经系统在非人类灵长类动物中的生物分布和安全性研究，水晶实验室 用表达正常人CLN2编码的AAV血清型r.10型进行了一项1期临床试验 序列(AAVRH.10hCLN2，LEX08)用于治疗儿童CLN2病。中枢神经系统实质内(IP) LEX08疗法达到了显著减缓神经功能衰退临床进展的1°终点， 定量评估运动+语言下降42.4-47.5% 与2个不同的未经治疗的自然病史对照队列进行功能比较。然而，虽然知识产权管理 LEX08显著延缓了疾病的进展，但并没有完全阻止疾病的进展，提示 推测IP路由可能不足以分发向量和/或向量TPP-I产品 在整个中枢神经系统。第一阶段STTR的重点是评估通过多个- 将LEX08运送到CNS的PLE路线将实现TPP-I的更广泛分布，从而产生有效的- 能够更彻底地阻止疾病进展的激励性治疗。目标1.评估假设 采用脑实质内+脑池内+脑室内3种平行给药途径， 载体衍生的TPP-I产物将分布在非人类灵长类动物的整个中枢神经系统中，结果是 TPP-I酶活性高于本底两个标准差的百分比CNS的2倍 单独的实质内路径。拟议的对非人类灵长类动物的研究将包括在 8周后LEX08 DNA、mRNA和TPP-I酶活性在中枢神经系统的生物分布。因为- 多路由策略提供了比单独的IP路由更广泛的分布， LEXEO将申请与FDA举行IND前会议的第二阶段STTR，LEX08的GMP生产，用于- MAL毒理学研究，以及当前IND的修订。

Abstract. In partnership with the Crystal laboratory, Weill Cornell, LEXEO is developing an adeno-associ- ated virus (AAV)-based gene therapy to treat the central nervous system (CNS) manifestations of CLN2 (Batten) disease, a fatal, childhood autosomal recessive neurodegenerative lysosomal storage disorder caused by mutations in the CLN2 gene, coding for a lysosomal enzyme, tripeptidyl peptidase 1 (TPP-I). The loss of TPP-I activity leads to accumulation of storage material in lysosomes and resultant neuronal cell death with progressive neurodegeneration. Genotype/phenotype comparisons suggest that the severe phenotype should be ameliorated with increase of CNS TPP-I levels to 5 to 10% of normal. This possibly can be achieved using an AAV vector efficient in transferring genes to the CNS, mediating persistent ex- pression of TPP-I, a secreted protein capable of cross-correcting neighboring cells via uptake by the man- nose-6-phosphate receptor. However, since the CNS manifestations of CLN2 disease are throughout the brain, it is essential that the therapy mediates wide distribution in the CNS. Based on efficacy studies in CLN2-/- mice, and CNS biodistribution and safety studies in nonhuman primates, the Crystal laboratory carried out a phase 1 clinical trial with the AAV serotype rh.10 expressing the normal human CLN2 coding sequence (AAVrh.10hCLN2, LEX08) to treat children with CLN2 disease. CNS intraparenchymal (IP) LEX08 therapy met the 1° endpoint of significantly slowing the clinical progression of neurologic decline, with 42.4 - 47.5% % reduction in the quantitative assessment of the rate of decline of motor + language function compared to 2 different untreated natural history control cohorts. However, while IP administration of LEX08 significantly slowed the progression of the disease, it did not completely halt progression, sug- gesting that the IP route may not be sufficient to distribute the vector and/or the vector TPP-I product throughout the CNS. The focus of the phase I STTR is to assess whether parallel administration via multi- ple routes of delivery of LEX08 to the CNS will achieve broader distribution of TPP-I, resulting in an effec- tive therapy that more completely halts progression of the disease. Aim 1. To assess the hypothesis that by using 3 parallel routes of administration, intraparenchymal + intracisternal + intracerebroventricular, the vector-derived TPP-I product will be distributed throughout the CNS of nonhuman primates with resulting TPP-I enzyme activity greater than two standard deviations above background in >2 fold of the % CNS by the intraparenchymal route alone. The proposed studies in nonhuman primates will include assessment at 8 wk of CNS biodistribution of LEX08 DNA, mRNA and TPP-I enzyme activity throughout the CNS. As- suming the multi-route strategy provides significantly broader distribution than that of the IP route alone, LEXEO will apply for a phase II STTR for a pre-IND meeting with the FDA, GMP production of LEX08, for- mal toxicology studies, and revision of the current IND.