Supplemental Grant Request to existing 5U01AG053247 - 03 - TK/PK Assay Analysis and Development

5U01AG053247-3补充请求摘要 治疗阿尔茨海默病的ACU-193的开发现在正在进入最终的IND使能阶段 部分非临床研究，包括首先是非GLP，然后是GLP毒理学 学习。毒理学研究完成后，目前的计划是敲定和 向FDA提交IND。第一阶段协议的设计已经达成一致，协议 将于2020年初撰写。此外，与FDA的C型互动发生在 2018年12月提出的会议请求。FDA并不认为有必要召开会议，但 2019年2月对简报文件中提出的3个问题提供了书面反馈。这个 FDA对IND中的额外非临床数据提出了相对较小的要求，这将是 如果是这样的话。FDA原则上同意简报文件中描述的研究设计， 尽管他们确实要求在研究的单剂部分小幅增加样本量 我会这么做的。这项研究的第一次患者访问计划在2020年第四季度进行。 为了支持非GLP毒代动力学(TK/PK)剂量范围研究，基础 建立了电化学发光免疫分析(ECLIA)方法 猕猴血浆中ACU-193的测定。相比之下，同样的基本 该方法被证明是不可接受的，当应用于SD大鼠的血浆时。具体来说， 在分析动态范围的上端注意到过多的不精密度。这排除了 可靠地量化计划剂量中预期的高ACU-193浓度- 范围广泛的研究。一系列额外的实验表明，干扰物质是 存在于一些但不是所有的老鼠体内。桥接ECLIA的并行开发 食蟹猴和食蟹猴血清中抗药抗体的特征 SpragueDawley大鼠在选定的药物朴素中表现出反应性，有时是相当高的反应性 老鼠。在食蟹猴的血清中未观察到这种反应。这个 大鼠PK/TK实验中的干扰物质和大鼠ADA实验中的反应性最终 确定为鼠抗人免疫球蛋白抗体。当存在时，这些抗体 干扰大鼠血浆中ACU-193的测定，并表现为血清中的ADAs 治疗幼稚的老鼠。不幸的是，资金原本打算覆盖预期的， 必须花费大鼠TK和大鼠ADA分析的直接开发和鉴定 确定问题的原因并修改基本的分析格式以解决潜在的问题 问题。现在正在申请补充资金，以支付完成 初步规划的开发和鉴定工作。有了这笔额外的资金，我们相信 临床试验的第一次患者探视可以毫不迟疑地开始。 因此，Acumen制药公司要求为现有的赠款提供25万美元的补充赠款 5U01AG053247-03，完成大鼠TK/PK和ADA检测方法的建立。这个 如上所述的技术挑战需要与CRO签订额外的合同时间，以 制定合格的方法来支持非GLP剂量范围研究，并随后完全 验证这些分析方法，以便它们可能支持计划的GLP毒理学 学习。这些分析作为IND应用程序的一部分是至关重要的，目前计划用于 2020年9月。所要求的额外经费将允许开展更多的工作 并将减少需要在以后的日期提交IND的风险。 TK/PK检测的额外诊断活动和验证工作估计为 估计约为70,000美元，ADA检测的额外开发工作是 估计约为180000美元。

5U01AG053247-3 Supplemental Request Summary The development of ACU-193 for Alzheimer’s disease is now reaching the final IND-enabling portions of the non-clinical research, including first non-GLP followed by GLP toxicology studies. Following completion of the toxicology studies, the current plan is to finalize and submit an IND to FDA. The design of the Phase 1 protocol has been agreed on and the protocol will be written early in 2020. Additionally, a Type C interaction with FDA occurred with a meeting request made in December 2018. The FDA did not feel that a meeting was required but provided written feedback in February 2019 to 3 questions posed in the Briefing Document. The FDA made relatively minor requests for additional non-clinical data in the IND, which will be provided. FDA agreed in principle to the study design as described in the Briefing Document, although they did ask for a small increase in sample size in the single dose portion of the study which will be done. First patient visit for the study is planned for 4Q2020. In support of non-GLP toxicokinetic (TK/PK) dose-ranging studies, a basic electrochemiluminescent immunoassay (ECLIA) method was developed and readily qualified for measurement of ACU-193 in Cynomologous monkey plasma. In contrast, the same basic method proved unacceptable when applied to plasma from Sprague Dawley rats. Specifically, excessive imprecision was noted at the upper end of the assay dynamic range. This precluded reliable quantification of the high ACU-193 concentrations anticipated in the planned dose- ranging studies. A series of additional experiments revealed that interfering substances were present in some but not all rats. Parallel development of a bridging ECLIA for detection and characterization of Anti-Drug Antibodies (ADA) in serum from Cynomologous monkey and Sprague Dawley rat revealed reactivity, sometimes quite high reactivity, in selected drug naïve rats. No such reactivity was observed in sera obtained from Cynomolgus monkeys. The interfering substances in the rat PK/TK assay and reactivity in the rat ADA assay were ultimately determined to be rat anti-human immunoglobulin antibodies. When present, these antibodies interfered with the measurement ACU-193 in rat plasma and behaved like ADAs in the serum of treatment naïve rats. Unfortunately, funds originally intended to cover an anticipated, straightforward development and qualification of the rat TK and rat ADA assays had to be spent to define the cause of the problem and modify basic assay formats to resolve that underlying issue. Supplemental funding is now being requested to cover the costs for completing the initially planned development and qualification work. With this additional funding, we believe that first patient visit for the clinical trial can begin without a delay. Acumen Pharmaceuticals is thus requesting a $250,000 Supplemental Grant to the existing Grant 5U01AG053247 - 03 to complete the development of the rat TK/PK and ADA assays. The technical challenges as described above are requiring additional contracted time with the CRO to produce qualified methods to support non-GLP dose ranging studies and subsequently fully validate these analytical methods so that they might support the planned GLP Toxicology studies. These assays are critical as part of the IND application which is currently scheduled for September 2020. The requested additional funding will allow additional work to be performed immediately and will reduce the risk that the IND would need to be submitted at a later date. The estimated additional diagnostic activities and validation work for the TK/PK assays is estimated to be approximately $70,000, and additional development work on the ADA assay is estimated to be approximately $180,000.