Treatment of Lafora disease with an antibody-enzyme fusion

拉福拉病(LD)是一种致命的儿童癫痫，是一种非经典的糖原储存障碍，没有 治疗或治愈。在过去的15年里，我们和其他人已经定义了LD的分子基础 准备好这个领域来治愈这种可怕的疾病。LD的一个特征是胞浆内异常的糖原样包涵体 被称为拉福拉小体(Lbs)，聚集在包括大脑在内的大多数组织的细胞中。像病人一样，LD 出现LBS和神经变性的小鼠模型。通过遗传方法减少糖原合成 消除淋巴滤泡的形成，挽救LD小鼠模型的神经表型。因此，当前的一个焦点是 该领域的目的是减少体重，以治疗LD为目标。 Valarie治疗公司利用抗体片段设计了一种细胞递送平台，使其能够 抗体-酶融合(AEF)将蛋白质运送到无数细胞中。在与Valarion的合作中，我们 最近确定了清除LBS的治疗策略。这涉及到使用一种新的定向功能 融合到活性的LB降解淀粉酶，称为VAL-0417和VAL-1221。我们已经完成了体外实验 概念实验发现，VAL-0417和VAL-1221会降解LBS。进一步，进行了现场试验 证明它们能穿透细胞，并且在细胞中很活跃。令人惊讶的是，我们看到 侧脑室注射Val-0417和Val-1221可有效降解LD小鼠LBS 模型，将LD小鼠大脑中的总葡聚糖水平降低到接近WT水平。 Pompe病是一种典型的糖原蓄积性疾病，由溶酶体酸α缺乏引起。 通常能降解糖原的葡萄糖苷酶(GAA)。Valarie已经完成了Val-的临床前研究 1221，并启动了1/2期临床试验。这项试验涉及Val1221的静脉给药。然而， 目前的VAL-1221配方不适合人体脑室注射。因此，这项建议将： 赠款R61阶段的具体目标(1年) 具体目标1-重新配制VAL-1221，用于ICV交付。将进行一系列进行/不进行的研究，以 优化Val-1221的活性和稳定性。我们还将确定大脑的生物分布， 脑室注射Val-1221的药代动力学(PK)和药效学(PD)参数。 赠款R33阶段的具体目标(2年) 具体目标2-建立脑室注射Val-1221的最佳体内给药策略。我们会给你注射一剂 升级研究，以确定ICV Val-1221的最大耐受量，以及将 评估脑室注射Val-1221最有效改善葡聚糖的持续时间和频率 具有广泛病理负荷的Laforin基因敲除小鼠的大脑清除，即Lbs。 我们准备进行将这种疗法转化为临床所需的临床前研究。 此外，VAL-1221是一种具有超越LD潜力的新方法。

Lafora disease (LD) is a fatal childhood epilepsy and a non-classical glycogen storage disorder with no treatment or cure. Over the last 15 years, we and others have defined the molecular underpinnings of LD that position the field to cure this horrific disease. A hallmark of LD is cytosolic aberrant glycogen-like inclusions known as Lafora bodies (LBs) that accumulate in cells of most tissues, including the brain. Like patients, LD mouse models present with LBs and neurodegeneration. Reduced glycogen synthesis via genetic methods eliminates LB formation and rescues the neurological phenotype in LD mouse models. Thus, a current focus in the field is to decrease LBs with the goal of treating LD. Valerion Therapeutics has engineered a cell delivery platform utilizing antibody fragments allowing their antibody-enzyme fusions (AEFs) to deliver a protein into a myriad of cells. In collaboration with Valerion, we recently identified therapeutic strategies to clear LBs. This involves use of a novel targeting functionality fused to active LB-degrading amylases, called VAL-0417 and VAL-1221. We have completed in vitro proof of concept experiments and found that VAL-0417 and VAL-1221 degrade LBs. Further, in situ experiments demonstrate that they penetrate cells and they are active in cells. Strikingly, we see that intracerebroventricular (ICV) injection of VAL-0417 and VAL-1221 efficiently degrade LBs in LD mouse models, lowering total glucan levels of LD mouse brains to near WT levels. Pompe disease is a classical glycogen storage disease caused by lack of the lysosomal enzyme acid α- glucosidase (GAA) that normally degrades glycogen. Valerion has completed pre-clinical studies with VAL- 1221 and initiated a Phase 1/2 clinical trial. This trail involves IV administration of VAL-1221. However, the current VAL-1221 formulation is not suitable for human ICV injections. Therefore, this proposal will: Specific Aims for the R61 phase of the grant (1 year) Specific Aim 1 – Reformulate VAL-1221 for ICV delivery. A series of go/no-go studies will be performed to optimize the activity and stability of VAL-1221. We will also determine the brain biodistribution, pharmacokinetic (PK), and pharmacodynamic (PD) parameters of ICV VAL-1221. Specific Aims for the R33 phase of the grant (2 years) Specific Aim 2 – Establish the optimal in vivo dosing strategy for ICV VAL-1221. We will perform a dose escalation study to determine the maximum tolerated dose of ICV VAL-1221, along with studies that will assess the duration and frequency of ICV VAL-1221 administration that most efficaciously improves glucan clearance from the brains of Laforin knockout mice that have extensive pathological load, i.e. LBs. We are poised to perform the preclinical research required to translate this therapy into the clinic. Additionally, VAL-1221 is a novel approach with potential beyond LD.