Manufacture of aseptic, purified, cryopreserved Plasmodium vivax sporozoites

摘要 由间日疟原虫（Pv）寄生虫引起的疟疾在发病率方面排名第二， 恶性疟原虫（Pf）疟疾排在首位。然而，与Pf不同，化疗 针对Pv的预防措施不能预防Pv特有的复发，复发是由于Pv的重新激活而发生的。 被称为催眠虫的寄生虫的持续性肝脏阶段睡眠形式。伯氨喹是唯一一种 靶向Pv催眠虫，但在G6 PD患者中可引起危及生命的急性溶血性贫血 缺乏症是最普遍的人类遗传性疾病，影响了疟疾流行国家8%的人。 开发更好的药物或生产急需的疫苗的努力进一步受到阻碍， 在体外繁殖Pv寄生虫的血液阶段，不像Pf。 控制人类疟疾感染（CHMI）作为评估抗Pv药物和疫苗的一种手段， 用Pv疟疾患者的新鲜的、被Pv感染的血液喂养蚊子。所有这些 瓶颈使得开发和测试针对Pv疟疾的强有力干预措施的任务更具挑战性 我们在第一阶段赠款下取得了重大进展， 无特定病原体（SPF）的玻利维亚塞米里鱼（Sb）的菌落。和瓶装的无菌纯化疟原虫 使用来自SPF Sb的感染血液在无菌蚊子中产生间日疟原虫（Pv）子孢子（SPZ）， 所有过程中和放行均符合无菌性和放行标准。我们现在概述第二阶段的后续计划， 按照cGMP生产大量PvSPZ挑战品，进行质量控制放行和稳定性 研究，准备临床试验方案，并准备和提交研究性新药（IND）申请 沿着在人源化FRG KO huHEP小鼠中的感染性研究，以及免疫原性和 在小鼠模型中进行的保护功效研究，以寄生虫血症作为保护结果。产品 本提案中概述的研究结果将被称为Sanaria® PvSPZ挑战，与PfSPZ相似 挑战将为更大的疟疾社区提供评估药物和疫苗效力的工具 使用更安全的质量控制试剂对抗Pv疟疾， 不同的地段，在后勤上更可行的管理，并不受地理限制， 与使用蚊子叮咬的传统CHMI相比，这将是一个前所未有的里程碑， 疫苗学和疫苗制造领域，最重要的是，它将成为一个强大的基础， 预防Pv疟疾的一种疫苗方法，即PvSPZ 化学预防疫苗（PvSPZ-CVac）。

ABSTRACT Malaria caused by Plasmodium vivax (Pv) parasites is ranked second with respect to the incidence and severity of disease while Plasmodium falciparum (Pf) malaria is ranked first. However unlike Pf, chemo prophylactic measures against Pv do not prevent relapses, unique to Pv, that occur due to re-activation of persistent liver-stage sleeping forms of the parasites called hypnozoites. Primaquine is the only licensed drug that targets Pv hypnozoites, but it causes life threatening acute hemolytic anemia in patients with G6PD deficiency, the most prevalent human genetic disorder, affecting 8% of people in malaria-endemic nations. Efforts to develop better drugs or produce a much needed vaccine are further hampered by the inability to propagate blood stages of Pv parasites in vitro, unlike Pf. Therefore generating infected mosquitoes for controlled human malaria infection (CHMI) as a means to assess anti-Pv drugs and vaccines, is entirely reliant on feeding of mosquitoes on fresh, Pv-infected blood from patients with Pv malaria. Together, these bottlenecks make the task of developing and testing robust interventions against Pv malaria more challenging compared to Pf. We have made significant progress under a phase I grant toward establishing and maintaining a colony of specific pathogen free (SPF) Saimiri boliviensis (Sb). and vialing aseptic, purified Plasmodium vivax (Pv) sporozoites (SPZ) that were generated in aseptic mosquitoes using infected blood from SPF Sb and met asepticity and release criteria in all in process and for release. We now outline phase 2 follow-up plans to manufacture a lot of PvSPZ Challenge in compliance with cGMPs, conduct quality control release and stability studies, prepare a clinical trial protocol, and prepare and submit an Investigational New Drug (IND) application to the FDA along with an infectivity study in humanized FRG KO huHEP mice, and an immunogenicity and protective efficacy study in a mouse model with patent parasitemia as the protection outcome. The product resulting from studies outlined in this proposal will be called Sanaria® PvSPZ Challenge, and similar to PfSPZ Challenge will provide the larger malaria community with a tool to assess the efficacy of drugs and vaccines against Pv malaria with a safer quality-controlled reagent that exhibits minimal variability in potency between different lots, is logistically more feasible to administer, and is not subject to geographical limitations for application, compared to traditional CHMI using mosquito bites. It will represent an unprecedented milestone in the field of vaccinology, and vaccine manufacturing and most importantly it will form the basis of a powerful vaccine approach to preventing Pv malaria when administered with anti-malarial chemoprophylaxis, the PvSPZ chemoprophylaxis vaccine (PvSPZ-CVac).