Development of a novel adjuvant for vaccine sparing

描述（由申请人提供）：全球迫切需要开发新的和改进的疫苗来控制传染病，包括流感。疫苗接种仍然是控制这些疾病的最具成本效益的生物医学方法，但开发和生产足够数量的流感疫苗已被证明是有问题的。迄今为止，使用铝基佐剂（明矾）的临床试验--这是美国唯一获得许可的佐剂--与大流行性流感病毒疫苗组合，未能提供对流感特异性应答具有显著免疫刺激作用的证据。供应问题的一个有希望的解决方案是将保留抗原的佐剂掺入疫苗制剂中，从而促使寻找能够安全地提高保护性抗流感抗体滴度以最小化免疫原消耗的替代佐剂，同时仍然提高疫苗效力，从而增加可用疫苗剂量的数量。我们已经从盘尾丝虫（Onchocerca volvulus）（rASP-1）中鉴定出具有内在免疫刺激特性的天然分泌蛋白，并表明它是一种强大的免疫刺激佐剂;它促进平衡的Th 1/Th 2抗体应答和对几种可溶性疫苗候选抗原和商业灭活病毒疫苗（包括三价灭活流感疫苗（TIV））的细胞应答。此外，rASP-1蛋白诱导幼稚人DC的成熟和活化，并增强其作为APC的活性。它还通过激活树突状细胞（DCs）和TLR 2和TLR 4受体刺激Th 1偏向的细胞因子从正常PBMC分泌，表明rASP-1是一种新的免疫刺激佐剂。我们建议通过设计一种集中的临床前和产品开发方法来最大限度地提高其有前途的有益应用，该方法最终将在简单的水性制剂中生产高效安全的rASP-1佐剂流感疫苗，该制剂每剂需要最小的抗原量。通过这种方式提高疫苗效力，我们可以有效地增加可用疫苗剂量的数量。 我们计划使用酵母表达系统开发rASP-1佐剂的可扩展生产工艺;它将采用一系列用于过程中、缓冲液配制、放行和稳定性测试的关键测定。我们将在体外评估功能性和效力，然后验证在小鼠和雪貂中使用最少的免疫原消耗联合接种TIV流感疫苗一次免疫后所需抗体和细胞反应的诱导。我们相信该项目将产生汇编/提交IND和进入人用rASP-1佐剂临床开发所需的所有信息和过程。该申请有三个目的：1）rASP-1佐剂的工艺开发、表征、缓冲液配制和稳定性测试; 2）使用抗原剂量节省的rASP-1佐剂流感疫苗的有效性测试;以及3）技术转让、cGMP生产、GLP毒理学和IND制备。

DESCRIPTION (provided by applicant): There is urgent need worldwide for the development of new and improved vaccines to control infectious diseases, including influenza. Vaccination remains the most cost-effective biomedical approach for controlling these diseases, but developing and producing the flu vaccines in sufficient quantities has proved problematic. To date, clinical trials with aluminum-based adjuvants (alum)-the only ones licensed in the U.S.-in combination with pandemic influenza virus vaccines, have failed to provide evidence of a significant immunostimulating effect on influenza-specific responses. A promising solution to the supply problem is to incorporate an antigen-sparing adjuvant(s) into vaccine formulations, prompting the search for alternative adjuvants capable of safely boosting protective anti-influenza antibody titers to minimize immunogen consumption, while still enhancing vaccine efficacy and thus increasing the number of available vaccine doses. We have identified a naturally occurring secreted protein with intrinsic immunostimulatory properties from Onchocerca volvulus (rASP-1) and showed that it is a powerful immunostimulatory adjuvant; it promotes a balanced Th1/Th2 antibody response and cellular responses to several soluble vaccine candidate antigens, and commercial inactivated viral vaccines, including trivalent-inactivated flu vaccines (TIV). Further, the rASP-1 protein induces maturation and activation of naive human DCs and potentiates their activity as APCs. It also stimulates Th1-biased cytokine secretion from normal PBMCs via the activation of dendritic cells (DCs) and the TLR2 and TLR4 receptors, suggesting that rASP-1 is a novel immunostimulatory adjuvant. We propose to maximize its promising beneficial applications by designing a focused preclinical and product development approach that will ultimately produce a highly effective and safe rASP-1 adjuvanted flu vaccine in a simple aqueous formulation that requires a minimal antigen quantity per dose. By enhancing vaccine efficacy in this way, we can effectively increase the number of vaccine doses available. We plan to develop a scalable production process for the rASP-1 adjuvant using the yeast expression system; it will feature a series of critical assays used for in-process, buffer formulation, release, and stability testing. We will evaluate functionality and potency in vitro an then validate the induction of the desired antibody and cellular responses after one immunization with the co-administered TIV flu vaccine in mice and ferrets using minimal immunogen consumption. We are confident the project will produce all the information and processes necessary for compilation/ submission of an IND and entry into clinical development of the rASP-1 adjuvant for human use. The application has three aims: 1) process development, characterization, buffer formulation, and stability testing of the rASP-1 adjuvant; 2) efficacy testing of the rASP-1 adjuvanted flu vaccine using antigen dose sparing; and 3) technology transfer, cGMP manufacture, GLP toxicology, and IND preparation.