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

5 U 01 AG 053247 -3补充请求摘要 ACU-193治疗阿尔茨海默病的开发现已达到最终IND 部分非临床研究，包括首次非GLP研究，随后是GLP毒理学研究 问题研究毒理学研究完成后，目前的计划是最后确定和 向FDA提交IND。已就第1阶段方案的设计达成一致， 将于2020年初完成。此外，与FDA的C型相互作用发生在 2018年12月提出的会议要求。FDA认为不需要召开会议， 于2019年2月就简报文件中提出的3个问题提供了书面反馈。的 FDA对IND中的额外非临床数据提出了相对较小的要求， 提供了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次给药部分增加少量样本量 我会完成的研究的首次患者访视计划于2020年第4季度进行。 为了支持非GLP毒代动力学（TK/PK）剂量范围研究， 电致发光免疫分析（ECLIA）方法的发展和容易确认 食蟹猴血浆中ACU-193的测定。相反，同样的基本 当应用于Sprague道利大鼠的血浆时，该方法被证明是不可接受的。具体地说， 在测定动态范围的上限处注意到过度的不精确性。这就排除了 计划剂量中预期的高ACU-193浓度的可靠定量- 范围研究。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中。平行开发用于检测和分析的桥接ECLIA 食蟹猴血清中抗药物抗体（ADA）的表征 Sprague道利大鼠在选定的药物初治大鼠中显示出反应性，有时相当高的反应性。 大鼠在食蟹猴血清中未观察到此类反应性。的 最终确定了大鼠PK/TK试验中的干扰物质和大鼠ADA试验中的反应性 确定为大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的测量，并表现出与大鼠血清中ADA相似的行为。 未经处理的大鼠。不幸的是，资金原本打算支付预期的， 必须花费大鼠TK和大鼠ADA试验的直接开发和确认 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.目前正在请求补充资金，以支付完成 最初计划的开发和鉴定工作。有了这笔额外的资金，我们相信 临床试验的第一个患者访问可以开始而没有延迟。 因此，Acumen Pharmaceuticals要求在现有赠款的基础上追加25万美元的赠款 5 U 01 AG 053247 - 03，以完成大鼠TK/PK和ADA试验的开发。的 如上所述的技术挑战需要与CRO签订额外的合同时间， 产生合格的方法来支持非GLP剂量范围研究， 验证这些分析方法，以便它们可以支持计划的GLP毒理学 问题研究这些测定作为IND申请的一部分至关重要，该申请目前计划于 2020年9月。所要求的额外资金将使更多的工作得以开展 立即提交，并将降低需要在稍后日期提交IND的风险。 TK/PK试验的估计额外诊断活动和验证工作为 估计约为70，000美元，ADA检测的额外开发工作 估计约为18万美元。

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.