In vitro bioreactor production of a genetically modified late liver stage-arresting replication competent Plasmodium falciparum sporozoite vaccine

体外生物反应器生产具有复制能力的转基因晚期肝阶段恶性疟原虫子孢子疫苗

• 批准号: 10547414
• 负责人: B. KIM LEE SIM
• 金额: $ 30万
• 依托单位: SANARIA, INC.
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-03 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10547414
• 关键词: Africa; Africa South of the Sahara; African; Antigens; Antimalarials; Area; Attenuated; Authorization documentation; Bioreactors; Bite; Blood; COVID-19; Cerebral Malaria; Cessation of life; Characteristics; Chemoprophylaxis; Child; Chloroquine; Clinical; Clinical Trials; Communities; Cryopreservation; Culicidae; Detection; Development; Disease; Dissection; Dose; Ensure; Erythrocytes; Europe; Falciparum Malaria; Female; Fiber; Generations; Genes; Geographic Locations; Geography; Goals; Harvest; Hepatocyte; Hospitalization; Human; Immunization; Immunization Programs; Immunize; In Vitro; Individual; Infant; Infection; Infection prevention; Licensure; Liver; Malaria; Malaria Vaccines; Marketing; Mass Vaccinations; Medical; Metabolic; Methods; Mus; Netherlands; Oocysts; Parasites; Pathology; Persons; Phase; Phase III Clinical Trials; Plasmodium falciparum; Plasmodium falciparum vaccine; Pregnant Women; Prevention; Procedures; Process; Production; Quality Control; Radiation; Safety; Salivary Glands; Sporozoite vaccine; Sporozoites; Symptoms; Vaccination; Vaccine Production; Vaccines; Vial device; base; cost; human model; humanized mouse; in vivo; malaria infection; malarial anemia; male; mortality; mouse model; next generation; prevent; programs; research clinical testing; tool; transmission process; vaccine efficacy

ABSTRACT In 2020 malaria caused 241M clinical episodes and 627,000 deaths, a significant increase from 2019. There were more deaths in Africa from malaria than from COVID-19. There is an urgent unmet medical need for a malaria vaccine that prevents infection and disease in individuals and can be deployed in mass vaccination programs for malaria elimination. Based on results of a pilot implementation program in >500,000 infants, RTS,S/AS01 was recommended in late 2021 by WHO for immunization of 5-month-olds with 4 immunizations administered over 21 months. RTS,S significantly reduced hospital admissions for malaria by 21% and severe malaria by 30%. It did not significantly reduce cerebral malaria, severe malaria anemia, or overall mortality, or prevent Plasmodium falciparum (Pf) infection. Of vaccines under development, only Sanaria’s PfSPZ vaccines have the efficacy against Pf infection to be considered for prevention of Pf infection in individuals or for geographically focused Pf malaria elimination campaigns. Sanaria’s 1st generation vaccine, PfSPZ Vaccine, is comprised of radiation-attenuated Plasmodium falciparum (Pf) sporozoites (SPZ), which arrest early in the liver stage. Phase 3 clinical trials will begin in mid 2022, and marketing authorizations in Europe (EMA) and the US (FDA) are planned for 2023/2024. Sanaria’s 2nd generation vaccine is PfSPZ-CVac (Chemoprophylaxis Vaccine). In PfSPZ-CVac, the parasites replicate in the liver, biologically amplifying the immunogen load by up to 50,000-fold and then are killed by an anti-malarial drug. PfSPZ-CVac co-administered with chloroquine (CQ), gave 100% vaccine efficacy (VE) against heterologous controlled human malaria infection (CHMI) 12 weeks after vaccination using 22% the dose of PfSPZ needed to achieve 80% VE against heterologous CHMI with PfSPZ Vaccine. PfSPZ-CVac (CQ) is more protective than PfSPZ Vaccine at ~1/5 the dose. However, transient symptoms of malaria can occur after 1st dose of PfSPZ, and if CQ is not administered appropriately, parasite multiplication in the blood could cause severe malaria. To retain the enhanced potency of PfSPZ- CVac and eliminate its drawbacks, we genetically altered Pf to be able to fully replicate, but arrest prior to entering the blood by deleting a single gene. The first of our late arresting replication competent (LARC) parasites called PfSPZ-LARC1, was completely attenuated in mice with humanized livers and in humans. To increase the potential safety of PfSPZ-LARC vaccines, we created a parasite with two genes deleted, PfSPZ- LARC2, which also arrests late in the liver stage. Sanaria has also achieved in vitro production of PfSPZ, referred to as iPfSPZ, thereby eliminating the need for mosquitoes in manufacturing PfSPZ vaccines and significantly increasing efficiency and decreasing costs of producing PfSPZ vaccines. In this project we will optimize in vitro production and purification of iPfSPZ-LARC2, produce aseptic, purified, cryopreserved iPfSPZ- LARC2 and demonstrate these iPfSPZ-LARC2 are infectious, and can develop into late liver stages but are attenuated. In the next phase, we will manufacture iPfSPZ-LARC2 for assessment in clinical trials.

抽象的 2020年，疟疾造成24100万个临床发作和627,000人死亡，比2019年显着增加。 我们在非洲的疟疾死亡人数多于19岁。紧急未满足的医疗需求 阻止个体感染和疾病的疟疾疫苗，可以部署在大规模疫苗中 消除疟疾的计划。根据> 500,000个婴儿的试点实施计划的结果， RTS，S/AS01在2021年末建议通过对4个月大的5个月大的免疫接种 管理21个月。 RTS，S将疟疾的住院大大降低了21％，重度 疟疾增加了30％。它没有显着降低脑疟疾，严重的疟疾贫血或整体死亡率或 预防恶性疟原虫（PF）感染。开发的疫苗，只有Sanaria的PFSPZ疫苗 具有针对PF感染的效率，以预防个体的PF感染或 以地理为重点的PF疟疾消除运动。 Sanaria的第一代疫苗PFSPZ疫苗是 辐射衰减的恶性疟原虫（PF）Sporozoites（SPZ），在肝脏早期停滞不前 阶段。第三阶段临床试验将于2022年中期开始，并在欧洲和美国进行营销授权 （FDA）计划于2023/2024。 Sanaria的第二代疫苗是PFSPZ-CVAC（化学预防 疫苗）。在PFSPZ-CVAC中，寄生虫在肝脏中复制，从生物学上通过上升来扩增免疫原负荷 至50,000倍，然后被抗疟疾药物杀死。 PFSPZ-CVAC与氯喹共同采用 （CQ），针对异源控制的人类疟疾感染（CHMI）12产生100％疫苗效率（VE）12 疫苗接种后数周使用22％的PFSPZ剂量以实现80％的VE与异源CHMI 与PFSPZ疫苗。 PFSPZ-CVAC（CQ）比剂量约1/5受到PFSPZ疫苗的保护。然而， 疟疾的短暂症状可以在PFSPZ 1剂后发生，如果CQ不能适当给药， 血液中的寄生虫繁殖可能导致严重的疟疾。保留PFSPZ-的效力增强 CVAC并消除了其缺点，我们通常更改PF，以便能够完全复制，但在之前逮捕 通过删除单个基因进入血液。我们晚期逮捕复制能力的第一个（LARC） 称为PFSPZ-LARC1的寄生虫在具有人性化生活和人类的小鼠中完全减弱。到 提高了PFSPZ-LARC疫苗的潜在安全性，我们创建了一个寄生虫，其两个基因已删除，PFSPZ- LARC2，它也在肝脏阶段后期逮捕。 Sanaria还实现了PFSPZ的体外生产， 称为IPFSPZ，从而消除了制造PFSPZ疫苗和 显着提高效率并降低生产PFSPZ疫苗的成本。在这个项目中，我们将 优化IPFSPZ-LARC2的体外生产和纯化，产生无菌，纯化，冷冻保存的IPFSPZ- LARC2并证明这些IPFSPZ-LARC2具有感染性，可以发展为晚期肝脏阶段，但是 衰减。在下一个阶段，我们将制造IPFSPZ-LARC2在临床试验中进行评估。