Schistosomiasis is a major parasitic disease which could impact up to a billion people in 74 countries. Current control strategies rely primarily on anti-parasitic drugs alone (praziquantel) which has proven inadequate due to both reinfection and the inherent threat of drug resistance. We have developed a potent schistosomiasis vaccine, termed SchistoShield, targeting a functionally important antigen (Sm-p80) formulated with a potent immune- stimulator (GLA-SE). SchistoShield has been exhaustively tested in rodents, rabbits, and baboons and has exhibited protection at all parasitic life-cycle stages including larvae, worms, and egg laying, survival, and excretion. We are completing our Phase II SBIR grant research focused on manufacture, lyophilization, and fill/finish of the antigen and will be entering into three clinical trials (first an NIH funded Phase 1 human trial in the USA, and next two Phase 1b trials funded by the European union which will be performed in Burkina Faso and Madagascar in Africa) beginning in the first quarter of 2020. To support our upcoming trials, this Phase IIb grant will focus on studies required to ensure stability of the vaccine drug product (DP) for the duration of the trials as required by regulatory agencies. The research will include assessing long-term stability, formal shipping studies, and development of a sensitive potency assay suitable for later stage clinical development. The potency assay will include immunization into mice followed by antibody titers after a single injection. We will forcibly degrade our antigen using simulated real-life conditions and test the altered protein for retention of immunological function using our potency assay. The goal will be to identify which quality parameters are directly indicative of a loss of potency. At the end of these studies we will have our DP on stability, formal shipping methods identified, a sensitive potency assay developed, and have identified critical quality parameters of potency of the vaccine. All these studies are required in preparation for Phase 2 and 3 clinical trials and future licensure and deployment.
A low-cost, effective vaccine for schistosomiasis would greatly aid in the fight against this debilitating disease. By producing a stable candidate vaccine antigen compliant with federal regulations for human clinical trials we intend to progress toward a commercial product leading to an improvement in global health.
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