Optimizing a small molecule inhibitor of SARS-CoV-2 replication and associated cytokine storm

优化 SARS-CoV-2 复制和相关细胞因子风暴的小分子抑制剂

• 批准号: 10470714
• 负责人: JEFFREY S GLENN
• 金额: $ 77.21万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10470714
• 关键词: 2019-nCoV; Address; Animal Model; Antiviral Agents; Antiviral resistance; Back; Biological Availability; Buffers; COVID-19; CYP3A4 gene; Caco-2 Cells; Cells; Development; Disease; Dose; Drug Kinetics; Enterovirus; Enterovirus 71; Future; Goals; Golgi Apparatus; Hour; Human; IL8 gene; In Vitro; Interferons; Interleukin-6; Lead; Lipids; Maximum Tolerated Dose; Mediating; Metabolic; Metabolism; Modeling; Modification; Mus; Oral; Organelles; Peripheral Blood Mononuclear Cell; Permeability; Pharmaceutical Chemistry; Phosphatidylinositols; Phosphotransferases; Production; Protein Isoforms; Resistance; Resistance development; Ritonavir; Role; SARS coronavirus; SARS-CoV-2 infection; SARS-CoV-2 inhibitor; Serum; Severe Acute Respiratory Syndrome; Site; Small Interfering RNA; Structure-Activity Relationship; Testing; Therapeutic Index; Tissues; Toxic effect; Viral; Virulent; analog; animal safety; cytokine; cytokine release syndrome; drug development; experimental study; improved; in vivo; inhibitor; knock-down; lead optimization; mouse model; multidisciplinary; nanomolar; novel; pre-clinical; remdesivir; safety study; severe COVID-19; small molecule inhibitor; standard of care; synergism; virology

Our goal is to develop towards an IND a novel class of small molecule inhibitors of phosphoinositide (PI) 4 kinase IIIb (PI4KIIIb) with potent dual activity against both SARS-CoV-2 and the excess cytokine release associated with COVID-19 disease. Entry of SARS-CoV has been shown to depend on PI4KIIIb, and strong inhibition of entry was achieved following knockdown of PI4KIIIb via siRNA, and SARS-CoV-2 is believed to enter cells via a similar mechanism. This likely reflects a requirement for enrichment of phosphorylated isoforms of PI, such as PI-4, in the lipid organelle required for viral fusion upon entry. We have developed potent and specific small molecule inhibitors of PI4KIIIb, and optimized them for high oral bioavailability. Our lead inhibitor, STF-1019 has nanomolar efficacy against enteroviruses (EV) which are also dependent on PI4KIIIb, and is the only molecule to have demonstrated in vivo efficacy in the animal model of EV-71, and without toxicity. We have now shown that STF-1019’s EC50 against SARS-CoV-2 is 210 nM, with a CC50 of >100 microM, reflecting a therapeutic index (TI) of ~500. Finally, likely due to PI4KIIIb’s role in Golgi-mediated secretion, we have also recently shown that STF-1019 can potently inhibit the LPS-induced secretion of IL-6 from human PBMC. STF-1019’s metabolic stability, however, is suboptimal, requiring co-administration with an inhibitor (i.e. ritonavir) of its metabolism by CYP3A4 for optimal sustained tissue exposure. We hypothesize that: 1) STF-1019’s SAR and major metabolites indicates that our lead PI4KIIIb inhibitor can be further optimized to increase its activity and metabolic stability to achieve an optimal exposure profile; 2) modifications that further increase PI4KIIIb inhibition can provide a buffer for modifications that may increase metabolic stability at the expense of efficacy; 3) the optimized inhibitor will inhibit SARS-CoV-2 in vitro, and in vivo; 4) the optimized inhibitor will have a high barrier to the development of resistance; 5) because of its orthogonal mechanism of action, our PI4KIIIb inhibitor can be used in combination with other agents to maximize efficacy; 6) STF-1019’s inhibition of IL-6 reflects an ability to modulate the release of other cytokines, and this non- antiviral activity can be of great additional benefit in addressing the cytokine storm associated with severe COVID-19 infection; 7) determination of key pharmacokinetic, in vitro ADME-Tox parameters and initial preclinical in vivo toxicity assessment of our optimized lead can advance its translational development, and form the basis of a future IND package. We propose the test these hypotheses by: 1) Identifying the STF-1019 analog (and back-up compound) with greatest in vivo trough:EC90 ratios; 2) determining the in vivo activity of the optimized PI4KIIIb inhibitors against SARS-CoV-2 and their effect on cytokine production; 3) determining the relative barrier to resistance, and potential for synergy with other agents; and 4) nominating a PI4KIIIb inhibitor IND candidate by subjecting the optimized lead to initial in vitro ADME-tox and IND-enabling preclinical animal safety studies.

我们的目标是开发一类新型磷酸肌醇 (PI) 4 小分子抑制剂 激酶 IIIb (PI4KIIIb) 具有针对 SARS-CoV-2 和过量细胞因子释放的有效双重活性 与 COVID-19 疾病相关。 SARS-CoV 的进入已被证明依赖于 PI4KIIIb，并且强烈 通过 siRNA 敲低 PI4KIIIb 后实现了进入抑制，并且 SARS-CoV-2 被认为 通过类似的机制进入细胞。这可能反映了对磷酸化物质富集的要求 PI 亚型，例如 PI-4，存在于病毒进入时融合所需的脂质细胞器中。我们开发了 PI4KIIIb 的有效且特异性小分子抑制剂，并对其进行了优化以获得高口服生物利用度。我们的 主要抑制剂 STF-1019 对肠道病毒 (EV) 具有纳摩尔级功效，这也依赖于 PI4KIIIb，是唯一在 EV-71 动物模型中证明体内功效的分子，并且 无毒性。我们现已证明 STF-1019 针对 SARS-CoV-2 的 EC50 为 210 nM，CC50 为 >100 microM，反映治疗指数 (TI) 约为 500。最后，可能是由于 PI4KIIIb 在高尔基体介导中的作用 分泌，我们最近还表明 STF-1019 可以有效抑制 LPS 诱导的 IL-6 分泌 来自人类 PBMC。然而，STF-1019 的代谢稳定性并不理想，需要与 CYP3A4 代谢的抑制剂（即利托那韦），以实现最佳的持续组织暴露。我们假设 1) STF-1019 的 SAR 和主要代谢物表明我们的主要 PI4KIIIb 抑制剂可以进一步 优化以提高其活性和代谢稳定性，以实现最佳暴露曲线； 2）修改 进一步增加 PI4KIIIb 抑制可以为可能增加代谢的修饰提供缓冲 以牺牲功效为代价的稳定性； 3)优化的抑制剂将在体外和体内抑制SARS-CoV-2； 4） 优化的抑制剂将对耐药性的产生具有较高的屏障； 5）由于其正交 作用机制，我们的 PI4KIIIb 抑制剂可以与其他药物联合使用，以最大限度地提高疗效； 6) STF-1019 对 IL-6 的抑制反映了调节其他细胞因子释放的能力，并且这种非- 抗病毒活性对于解决与严重疾病相关的细胞因子风暴具有巨大的额外益处 2019冠状病毒病感染; 7) 关键药代动力学、体外 ADME-Tox 参数和初始值的测定 我们优化的先导化合物的临床前体内毒性评估可以促进其转化开发，并且 形成未来 IND 计划的基础。我们建议通过以下方式测试这些假设：1) 识别 STF-1019 具有最大体内谷值的类似物（和备用化合物）：EC90 比率； 2) 测定体内活性 针对 SARS-CoV-2 的优化 PI4KIIIb 抑制剂及其对细胞因子产生的影响； 3）确定 耐药性的相对屏障以及与其他药物协同作用的潜力； 4) 提名 PI4KIIIb 抑制剂 IND 候选药物，通过对优化的先导化合物进行初始体外 ADME-tox 和 IND 启用 临床前动物安全性研究。