Prodrugs of Neuraminidase Inhibitors for Increased Oral Bioavailability

描述(申请人提供)：病毒编码的神经氨酸酶在流感病毒的生命周期中发挥关键作用。一类抑制神经氨酸酶作用的抗流感药物因其选择性和有效性而在制药行业引起了越来越多的兴趣。这些抑制剂是酶底物唾液酸的过渡态类似物，在体外和体内研究中都非常有效，IC50值在NM范围内。然而，这些药物的极性很强，因此口服生物利用度很差。在TSRL，我们开发了一种针对肠道转运体的氨基酸前体药物策略，以增强摄取。然后，被吸收的前药的后续激活可以通过前药的靶向酶解或将前药化学分解成激活的母体化合物来发生。这一策略是基于对细胞和组织中的运输和激活途径以及前药结构与这些途径的相互作用的分子机制的理解。在这个方案中，我们开发了两种神经氨酸酶抑制剂的新型氨基酸酰氧酯类前药，并提供了强有力的初步数据，表明这些前药由肠道转运体主动转运，并在原位肠道通透性模型中具有良好的肠道通透性。我们推测，通过这种前药方法，我们可以提高选定的神经氨酸酶抑制剂的口服利用度，使其能够被开发为口服药物产品。在目前的项目中，我们建议从稳定性、组织激活和生物利用度方面对一系列这些前药进行充分的表征。表现出可接受特征的化合物将通过犹他州州立大学的NIAID合同设施进行体内抗H1N1病毒有效性测试。我们的前药设计的分子机制方法在开发口服有效的神经氨酸酶抑制剂方面具有巨大的潜力。更广泛地说，这一前药战略在实现为更广泛的治疗有效的抗病毒药物开发可行的口服替代品这一最终目标方面提供了巨大的潜力和很大的希望。公共卫生相关性：TSRL已经开发出一种方法来提高抗流感药物的口服生物利用度，从而使它们适合口服给药。我们建议合成并测试一系列这些化合物作为口腔制剂的潜力。最终，这种方法可能会增加可用于治疗和预防流感的有效抗病毒化合物的数量。

DESCRIPTION (provided by applicant): Virally-encoded neuraminidase plays a key role in the life-cycle of the influenza virus. A class of anti-influenza drugs that inhibits the action of neuraminidase has garnered increasing interest in the pharmaceutical industry due to their selectivity and potency. The inhibitors are transition state analogs of the enzyme substrate, sialic acid, and are highly efficacious in in vitro and in vivo studies, with IC50 values in the nM range. However these drugs are very polar and consequently have poor oral bioavailability. At TSRL, we have a developed an amino acid prodrug strategy that targets intestinal transporters for enhanced uptake. Subsequent activation of the absorbed prodrug can then occur either through targeted enzymatic hydrolysis of the prodrug or chemical breakdown of the prodrug to the activate parent compound. This strategy is based on a molecular mechanistic understanding of the transport and activation pathways in cells and tissues and the interaction of prodrug structures with these pathways. In this proposal, we have developed novel amino acid acyloxy ester prodrugs of two neuraminidase inhibitors and provide strong preliminary data showing that these prodrugs are actively transported by intestinal transporter and have good intestinal permeability in an in situ intestinal permeability model. We hypothesize that through this prodrug approach, we can boost the oral availability of selected neuraminidase inhibitors to an extent that they can be developed as oral drug products. In the current project, we propose to fully characterize a series of these prodrugs with regard to their stability, tissue activation, and bioavailability. Compounds showing acceptable characteristics will be tested for in vivo efficacy against the H1N1 virus by the NIAID contract facility at Utah State University. Our molecular mechanistic approach to prodrug design has enormous potential for the development of orally effective neuraminidase inhibitors. More broadly, this prodrug strategy offers great potential and much promise in reaching the ultimate goal of developing viable oral alternatives for a wider range of therapeutically potent antiviral agents. PUBLIC HEALTH RELEVANCE: TSRL has developed an approach to improve the oral bioavailability of anti-influenza drugs, thus making them suitable for oral delivery. We propose to synthesize and test a series of these compounds for their potential as oral agents. Ultimately, this approach may increase the number of potent anti-virus compounds that are available for therapeutic and prophylactic treatment of influenza.