Nanocarrier formulated enzyme for the treatment of S. aureus infection

描述(申请人提供)：Lyso是一种对金黄色葡萄球菌具有溶菌作用的金属内肽酶，是治疗耐甲氧西林金黄色葡萄球菌(MRSA)感染的潜在系统疗法，包括心内膜炎、骨髓炎、导管相关感染以及MRSA介导的社区获得性真菌病和肺炎。然而，这种酶在体内的半衰期很短，尽管有积极的临床试验数据，但到目前为止，它还没有成为一种全身治疗方法。我们的Pharmain公司开发了一种纳米载体，受保护的接枝共聚物(PGC)，可以可逆地结合多肽和/或蛋白质(美国专利#7,138,105)，并具有可测量的解离常数(Kd)。重要的是，由于其大小，PGC纳米载体集中在血管通透性增加的部位，因此可能会在感染部位浓缩Lyso。我们的目标是开发一种Lyso的配方，以提供针对MRSA的挽救生命的治疗，并抑制耐药性的出现。我们的初步数据表明，PGC可以可逆地与Lyso结合，使血液半衰期增加14倍，并将其体内抗MRSA的效果提高100倍。我们建议制备无内毒素的lyso，并建立一个“主细胞库”(表达lyso的大肠杆菌)，用于：1)该项目满足我们lyso的需求，2)作为计划中的后SBIR IND申报和临床试验的参考细胞。我们还将通过合成初步数据中显示的有效PGC的变化(至少10个)来优化PGC的结构，以期进一步将半衰期延长到至少30倍。在我们向Ind投入大量资源之前，这一点很重要。为此，我们将继续开发PGC-lyso配方，对至少10个新的载体变体进行结合研究。我们将对至少6个选定的Lyso制剂进行pKs和生物分布研究。我们将确定我们的lyso制剂在体内对抗MRSA的有效性，并与商业上可获得的抗生素进行比较。Pharmain Corp.保密

DESCRIPTION (provided by applicant): Lyso, a metalloendopeptidase that is bacteriolytic for S. aureus, is a potential systemic therapy for treating methicillin-resistant S. aureus (MRSA) mediated infections including endocarditis, osteomyelitis, catheter related infections, and MRSA-mediated community acquired furunculosis and pneumonia. However, the short half-life of this enzyme in vivo has precluded its development thus far as a systemic therapy, despite positive clinical trial data. Our company, PharmaIN, has developed a nanocarrier, Protected Graft Copolymers (PGC), that can reversibly bind peptides and/or proteins (US patent #7,138,105) with measurable dissociation constant (Kd). Importantly, because of its size, PGC nanocarrier concentrates at sites of increased vascular permeability and thus can potentially concentrate lyso at the site of infection. Our goal is to develop a formulation of lyso to provide life-saving treatment against MRSA and to suppress the emergence of resistance. Our preliminary data demonstrates that PGC can reversibly associate with lyso, increase blood half-life 14-fold, and increase its in vivo efficacy against MRSA by 100-fold. We propose to prepare endotoxin- free lyso and create a "master cell-line bank" (E. coli expressing lyso) that will be used for: 1) this project to supply our lyso needs, and 2) as reference cells for the planned post-SBIR IND filing and clinical trial. We will also optimize the structure of PGC by synthesizing variations (at least 10) of the effective PGC shown in the preliminary data with the intention to further extend the half-life to at least 30 fold. This is important before we put a lot of resource towards IND. To this end, we will continue the development of PGC-lyso formulation by doing binding studies of at least 10 new carrier variations. We will do PKs and biodistribution studies on at least 6 selected lyso formulations. We will determine and compare with commercially available antibiotics the effectiveness of our lyso formulation in vivo against MRSA. PharmaIN Corp. Confidential