Final Preclinical Testing and Formulation of a Scalable, Live-attenuated SARS-CoV-2 Vaccine

项目总结 目前迫切需要能够大规模快速生产的有效SARS-CoV-2疫苗。vt.给出 我们对病毒的免疫反应的初步了解，一种产生一种 基础广泛的反应(天生的、体液的和细胞的)特别吸引人。此外，在很少或根本没有 对于关键免疫靶点的先验知识，能够将病毒的所有抗原呈现给宿主的疫苗是 非常理想。作为回应，Codagenix使用其独特的计算算法设计并完成了初始 一种鼻内减毒SARS-CoV-2疫苗CDX-005的临床前测试，它1)激活先天的， 体液和细胞免疫反应，2)将每个病毒抗原以其自然构象呈现给 接种宿主，3)廉价、快速、易于规模化生产。这是唯一的LAV 为美国市场开发的。该疫苗在完全特征化的GMP细胞和临床前生长旺盛 数据表明，在104-106pfu的范围内，单一的、低的鼻腔内剂量将具有保护作用。临床前 在叙利亚金黄地鼠身上的试验证明了CDX-005的安全性、减毒作用和体内疗效，以及 第一阶段临床试验将于2020年在英国开始，使用的是在海外制造的产品。我们的目标是 在美国生产和销售CDX-005 SARS-CoV-2疫苗。为此，Codagenix已经 有IND前与FDA的沟通和指导。我们建议完成额外的预 根据FDA的建议进行临床研究，并开发一种可长期稳定的配方 4°C的周期，以降低运输成本、简化最终用户存储并更易于管理 疫苗。因此，在目标1中，我们将开发一种在较长时间内稳定的CDX-005配方 2°-8°C。以我们的冷冻配方为基础，我们将测试辅料的稳定能力。 使用强制降解、加速稳定性测试和长期稳定性测试方案的液体疫苗。 在目标2中，我们将测定LATE的毒性、免疫原性、生物分布、减毒作用和疗效。 在叙利亚金黄地鼠中传代CDX-005。在为IND申请做准备时，我们将1)通过以下方式评估毒性 CDX-005接种后的组织病理学和血液学，2)检测CDX-005的免疫原性 血清免疫球蛋白酶联免疫吸附试验、空斑减少中和试验和定量聚合酶链式反应检测Th1/Th2反应，3)检测CDX-005 QPCR和TCID50在组织和排泄物中的生物分布和衰减，以及4)评估CDX-005的疗效 受到SARS-CoV-2挑战。在拟议工作的同时，我们将把CDX-005制造 能力转移到美国，在英国进行I期临床试验，并从这些组织中对病毒进行测序 让患者测试是否有可能逆转。我们认识到，其他SARS-CoV-2疫苗可能会上市 在CDX-005之前。虽然这些在抗击SARS-CoV-2的斗争中短期内将是一个巨大的福音，但 预计只能起到部分保护作用。相比之下，我们预计CDX-005作为LAV将提供 更强大和更持久的保护，使其成为长期市场中更具吸引力的选择。

PROJECT SUMMARY There is a critical need for effective SARS-CoV-2 vaccines that can be rapidly produced at large scale. Given our rudimentary understanding of the immunological responses to the virus, a vaccine that engenders a broad-based response (innate, humoral, and cellular), is particularly appealing. Further, with little or no a priori knowledge of key immunological targets, a vaccine that can present all of a virus’ antigens to the host is ideal. In response, using its unique computational algorithm, Codagenix has designed and completed initial pre-clinical testing of an intranasal, live-attenuated SARS-CoV-2 vaccine, CDX-005, that 1) activates innate, humoral, and cellular immune responses, 2) presents every viral antigen in its natural conformation to the inoculated host, and 3) will be inexpensive, fast, and easy to produce at scale. This is the only LAV being developed for the US market. The vaccine grows robustly in fully characterized GMP cells and pre-clinical data suggest that a single, low, intranasal dose in the range of 104-106 PFU will be protective. Pre-clinical testing in Syrian Golden hamsters demonstrated the safety, attenuation, and efficacy of CDX-005 in vivo, and a Phase I clinical trial will be beginning in the UK in 2020 using product manufactured overseas. Our goal is to produce and distribute the CDX-005 SARS-CoV-2 vaccine in the United States. To this end, Codagenix has had pre-IND communications with and guidance from the FDA. We propose to complete additional pre- clinical studies in response to FDA recommendations and to develop a formulation that is stable for extended periods at 4°C to reduce shipping costs, simplify end-user storage, and make it easier to administer the vaccine. Accordingly, in Aim 1, we will develop a CDX-005 formulation that is stable for extended periods at 2°-8°C. Starting with our frozen formulation as a base, we will test excipients for their ability to stabilize a liquid vaccine using forced degradation, accelerated stability testing, and long-term stability testing protocols. In Aim 2, we will determine the toxicity, immunogenicity, biodistribution, attenuation, and efficacy of late passage CDX-005 in Syrian Golden hamsters. In preparation for an IND filing, we will 1) assess toxicity by histopathology and hematology after inoculation with CDX-005, 2) examine CDX-005 immunogenicity by serum IgG ELISA, plaque reduction neutralization, and Th1/Th2 response by qPCR, 3) determine CDX-005 biodistribution and attenuation by qPCR and TCID50 in tissues and excretions, and 4) assess CDX-005 efficacy by SARS-CoV-2 challenge. In parallel with the proposed work, we will bring CDX-005 manufacturing capabilities to the US, conduct a Phase I clinical trial in the UK, and sequence the virus from tissues in these patients to test for possible reversion. We recognize that other SARS-CoV-2 vaccines may reach the market before CDX-005. While these will be a tremendous boon short term in the fight against SARS-CoV-2, the are expected to be only partially protective. In contrast, we anticipate that CDX-005, as an LAV, will provide a much more robust and longer lasting protection making it a more attractive choice in the long term market.