An Immunoadhesin Therapy for Inhalational Anthrax

描述（由申请人提供）：Planet Biotechnology正在开发PBI-220作为一种安全，有效和廉价的治疗对策，以对抗炭疽杆菌-一种威胁美国平民的药剂。PBI-220预计对天然和工程炭疽毒素具有广谱活性。PBI-220是一种重组嵌合蛋白，是一种免疫粘附素，由人受体、针对病原性靶标的诱饵和IgG-Fc组成，具有较长的循环半衰期和免疫效应细胞相互作用。PBI-220由CMG 2胞外结构域、炭疽毒素的人受体和人IgGl的Fc组成。我们建议使用吸入性炭疽的兔模型来进一步证明转基因烟草衍生的PBI-220的上级性能，然后通过在关键兔研究中直接比较来测试烟草衍生的和中国仓鼠卵巢（CHO）细胞衍生的PBI-220的性能。我们将确定在孢子激发后延迟治疗多长时间，并仍然保护动物免于死亡。此外，我们将直接比较植物和CHO细胞生产的PBI-220的功效。根据“动物规则”，本研究将被视为关键研究，并将用于证明在I期临床试验中检测PBI-220（来自一个或另一个来源）的合理性。

DESCRIPTION (provided by applicant): Planet Biotechnology is developing PBI-220 as a safe, effective and inexpensive therapeutic countermeasure to Bacillus anthracis - an agent threatening the U.S. civilian population. PBI-220 is expected to have broad spectrum activity against natural and engineered anthrax toxins. PBI-220, a recombinant chimeric protein, is an immunoadhesin comprised of a human receptor, a decoy against the pathogenic target, and an IgG-Fc, for a long circulating half-life and immune effector cell interaction. PBI-220 is comprised of the CMG2 extracellular domain, the human receptor for anthrax toxins, and the Fc of human IgGl. We propose to use the rabbit model of inhalation anthrax to further demonstrate the superior performance of PBI-220 derived from transgenic tobacco and then, to test, by direct comparison in a pivotal rabbit study, the performance of tobacco-derived and Chinese hamster ovary (CHO) cell-derived PBI-220. We will determine how long it is possible to delay treatment, following spore challenge, and still protect animals from death. In addition, we will directly compare the efficacy of the plant-made and CHO cell-made PBI-220s. This study will be considered a pivotal study, according to the "Animal Rule", and will be used to justify testing PBI-220, from one source or the other, in a Phase 1 clinical trial.